Clarify that the alloc_contig_pages() allocated range will always be
aligned to the requested nr_pages.
Link: https://lkml.kernel.org/r/1639545478-12160-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_pages_vma is meant to allocate a page with a vma specific memory
policy. The initial node parameter is always a local node so it is
pointless to waste a function argument for this. Drop the parameter.
Link: https://lkml.kernel.org/r/YaSnlv4QpryEpesG@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Ben Widawsky <ben.widawsky@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Arthur Marsh reported we would hit the error below when building kernel
with gcc-12:
CC mm/page_alloc.o
mm/page_alloc.c: In function `mem_init_print_info':
mm/page_alloc.c:8173:27: error: comparison between two arrays [-Werror=array-compare]
8173 | if (start <= pos && pos < end && size > adj) \
|
In C++20, the comparision between arrays should be warned.
Link: https://lkml.kernel.org/r/20211125130928.32465-1-sxwjean@me.com
Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Reported-by: Arthur Marsh <arthur.marsh@internode.on.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sl?b and vmalloc allocators reduce the given gfp mask for their internal
needs. For that they use GFP_RECLAIM_MASK to preserve the reclaim
behavior and constrains.
__GFP_NOLOCKDEP is not a part of that mask because it doesn't really
control the reclaim behavior strictly speaking. On the other hand it
tells the underlying page allocator to disable reclaim recursion
detection so arguably it should be part of the mask.
Having __GFP_NOLOCKDEP in the mask will not alter the behavior in any
form so this change is safe pretty much by definition. It also adds a
support for this flag to SL?B and vmalloc allocators which will in turn
allow its use to kvmalloc as well. A lack of the support has been
noticed recently in
http://lkml.kernel.org/r/20211119225435.GZ449541@dread.disaster.area
Link: https://lkml.kernel.org/r/YZ9XtLY4AEjVuiEI@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Support for GFP_NO{FS,IO} and __GFP_NOFAIL has been implemented by
previous patches so we can allow the support for kvmalloc. This will
allow some external users to simplify or completely remove their
helpers.
GFP_NOWAIT semantic hasn't been supported so far but it hasn't been
explicitly documented so let's add a note about that.
ceph_kvmalloc is the first helper to be dropped and changed to kvmalloc.
Link: https://lkml.kernel.org/r/20211122153233.9924-5-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit b7d90e7a5e ("mm/vmalloc: be more explicit about supported gfp
flags") has been merged prematurely without the rest of the series and
without addressed review feedback from Neil. Fix that up now. Only
wording is changed slightly.
Link: https://lkml.kernel.org/r/20211122153233.9924-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Chinner has mentioned that some of the xfs code would benefit from
kvmalloc support for __GFP_NOFAIL because they have allocations that
cannot fail and they do not fit into a single page.
The large part of the vmalloc implementation already complies with the
given gfp flags so there is no work for those to be done. The area and
page table allocations are an exception to that. Implement a retry loop
for those.
Add a short sleep before retrying. 1 jiffy is a completely random
timeout. Ideally the retry would wait for an explicit event - e.g. a
change to the vmalloc space change if the failure was caused by the
space fragmentation or depletion. But there are multiple different
reasons to retry and this could become much more complex. Keep the
retry simple for now and just sleep to prevent from hogging CPUs.
Link: https://lkml.kernel.org/r/20211122153233.9924-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "extend vmalloc support for constrained allocations", v2.
Based on a recent discussion with Dave and Neil [1] I have tried to
implement NOFS, NOIO, NOFAIL support for the vmalloc to make life of
kvmalloc users easier.
A requirement for NOFAIL support for kvmalloc was new to me but this
seems to be really needed by the xfs code.
NOFS/NOIO was a known and a long term problem which was hoped to be
handled by the scope API. Those scope should have been used at the
reclaim recursion boundaries both to document them and also to remove
the necessity of NOFS/NOIO constrains for all allocations within that
scope. Instead workarounds were developed to wrap a single allocation
instead (like ceph_kvmalloc).
First patch implements NOFS/NOIO support for vmalloc. The second one
adds NOFAIL support and the third one bundles all together into kvmalloc
and drops ceph_kvmalloc which can use kvmalloc directly now.
[1] http://lkml.kernel.org/r/163184741778.29351.16920832234899124642.stgit@noble.brown
This patch (of 4):
vmalloc historically hasn't supported GFP_NO{FS,IO} requests because
page table allocations do not support externally provided gfp mask and
performed GFP_KERNEL like allocations.
Since few years we have scope (memalloc_no{fs,io}_{save,restore}) APIs
to enforce NOFS and NOIO constrains implicitly to all allocators within
the scope. There was a hope that those scopes would be defined on a
higher level when the reclaim recursion boundary starts/stops (e.g.
when a lock required during the memory reclaim is required etc.). It
seems that not all NOFS/NOIO users have adopted this approach and
instead they have taken a workaround approach to wrap a single
[k]vmalloc allocation by a scope API.
These workarounds do not serve the purpose of a better reclaim recursion
documentation and reduction of explicit GFP_NO{FS,IO} usege so let's
just provide them with the semantic they are asking for without a need
for workarounds.
Add support for GFP_NOFS and GFP_NOIO to vmalloc directly. All internal
allocations already comply with the given gfp_mask. The only current
exception is vmap_pages_range which maps kernel page tables. Infer the
proper scope API based on the given gfp mask.
[sfr@canb.auug.org.au: mm/vmalloc.c needs linux/sched/mm.h]
Link: https://lkml.kernel.org/r/20211217232641.0148710c@canb.auug.org.au
Link: https://lkml.kernel.org/r/20211122153233.9924-1-mhocko@kernel.org
Link: https://lkml.kernel.org/r/20211122153233.9924-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2618c60b8b ("dma: make dma pool to use
kmalloc_node").
While working myself into the dmapool code I've found this little odd
kmalloc_node().
What basically happens here is that we allocate the housekeeping
structure on the numa node where the device is attached to. Since the
device is never doing DMA to or from that memory this doesn't seem to
make sense at all.
So while this doesn't seem to cause much harm it's probably cleaner to
revert the change for consistency.
Link: https://lkml.kernel.org/r/20211221110724.97664-1-christian.koenig@amd.com
Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: Yinghai Lu <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All callers pass NULL, so we can stop calculating the value we would
store in it.
Link: https://lkml.kernel.org/r/20211220205943.456187-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that we don't report it to the caller of reuse_swap_page(), we don't
need to request it from page_trans_huge_map_swapcount().
Link: https://lkml.kernel.org/r/20211220205943.456187-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
None of the callers care about the total_map_swapcount() any more.
Link: https://lkml.kernel.org/r/20211220205943.456187-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Check user page table entries at the time they are added and removed.
Allows to synchronously catch memory corruption issues related to double
mapping.
When a pte for an anonymous page is added into page table, we verify
that this pte does not already point to a file backed page, and vice
versa if this is a file backed page that is being added we verify that
this page does not have an anonymous mapping
We also enforce that read-only sharing for anonymous pages is allowed
(i.e. cow after fork). All other sharing must be for file pages.
Page table check allows to protect and debug cases where "struct page"
metadata became corrupted for some reason. For example, when refcnt or
mapcount become invalid.
Link: https://lkml.kernel.org/r/20211221154650.1047963-4-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Xu <weixugc@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have ptep_get_and_clear() and ptep_get_and_clear_full() helpers to
clear PTE from user page tables, but there is no variant for simple
clear of a present PTE from user page tables without using a low level
pte_clear() which can be either native or para-virtualised.
Add a new ptep_clear() that can be used in common code to clear PTEs
from page table. We will need this call later in order to add a hook
for page table check.
Link: https://lkml.kernel.org/r/20211221154650.1047963-3-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Xu <weixugc@google.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "page table check", v3.
Ensure that some memory corruptions are prevented by checking at the
time of insertion of entries into user page tables that there is no
illegal sharing.
We have recently found a problem [1] that existed in kernel since 4.14.
The problem was caused by broken page ref count and led to memory
leaking from one process into another. The problem was accidentally
detected by studying a dump of one process and noticing that one page
contains memory that should not belong to this process.
There are some other page->_refcount related problems that were recently
fixed: [2], [3] which potentially could also lead to illegal sharing.
In addition to hardening refcount [4] itself, this work is an attempt to
prevent this class of memory corruption issues.
It uses a simple state machine that is independent from regular MM logic
to check for illegal sharing at time pages are inserted and removed from
page tables.
[1] https://lore.kernel.org/all/xr9335nxwc5y.fsf@gthelen2.svl.corp.google.com
[2] https://lore.kernel.org/all/1582661774-30925-2-git-send-email-akaher@vmware.com
[3] https://lore.kernel.org/all/20210622021423.154662-3-mike.kravetz@oracle.com
[4] https://lore.kernel.org/all/20211221150140.988298-1-pasha.tatashin@soleen.com
This patch (of 4):
There are a few places where we first update the entry in the user page
table, and later change the struct page to indicate that this is
anonymous or file page.
In most places, however, we first configure the page metadata and then
insert entries into the page table. Page table check, will use the
information from struct page to verify the type of entry is inserted.
Change the order in all places to first update struct page, and later to
update page table.
This means that we first do calls that may change the type of page (anon
or file):
page_move_anon_rmap
page_add_anon_rmap
do_page_add_anon_rmap
page_add_new_anon_rmap
page_add_file_rmap
hugepage_add_anon_rmap
hugepage_add_new_anon_rmap
And after that do calls that add entries to the page table:
set_huge_pte_at
set_pte_at
Link: https://lkml.kernel.org/r/20211221154650.1047963-1-pasha.tatashin@soleen.com
Link: https://lkml.kernel.org/r/20211221154650.1047963-2-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Paul Turner <pjt@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Will Deacon <will@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With exit_mmap holding mmap_write_lock during free_pgtables call,
process_mrelease does not need to elevate mm->mm_users in order to
prevent exit_mmap from destrying pagetables while __oom_reap_task_mm is
walking the VMA tree. The change prevents process_mrelease from calling
the last mmput, which can lead to waiting for IO completion in exit_aio.
Link: https://lkml.kernel.org/r/20211209191325.3069345-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian@brauner.io>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom-reaper and process_mrelease system call should protect against races
with exit_mmap which can destroy page tables while they walk the VMA
tree. oom-reaper protects from that race by setting MMF_OOM_VICTIM and
by relying on exit_mmap to set MMF_OOM_SKIP before taking and releasing
mmap_write_lock. process_mrelease has to elevate mm->mm_users to
prevent such race.
Both oom-reaper and process_mrelease hold mmap_read_lock when walking
the VMA tree. The locking rules and mechanisms could be simpler if
exit_mmap takes mmap_write_lock while executing destructive operations
such as free_pgtables.
Change exit_mmap to hold the mmap_write_lock when calling unlock_range,
free_pgtables and remove_vma. Note also that because oom-reaper checks
VM_LOCKED flag, unlock_range() should not be allowed to race with it.
Before this patch, remove_vma used to be called with no locks held,
however with fput being executed asynchronously and vm_ops->close not
being allowed to hold mmap_lock (it is called from __split_vma with
mmap_sem held for write), changing that should be fine.
In most cases this lock should be uncontended. Previously, Kirill
reported ~4% regression caused by a similar change [1]. We reran the
same test and although the individual results are quite noisy, the
percentiles show lower regression with 1.6% being the worst case [2].
The change allows oom-reaper and process_mrelease to execute safely
under mmap_read_lock without worries that exit_mmap might destroy page
tables from under them.
[1] https://lore.kernel.org/all/20170725141723.ivukwhddk2voyhuc@node.shutemov.name/
[2] https://lore.kernel.org/all/CAJuCfpGC9-c9P40x7oy=jy5SphMcd0o0G_6U1-+JAziGKG6dGA@mail.gmail.com/
Link: https://lkml.kernel.org/r/20211209191325.3069345-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christian Brauner <christian@brauner.io>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jan Engelhardt <jengelh@inai.de>
Cc: Tim Murray <timmurray@google.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
linux/mm_types.h should only define structure definitions, to make it
cheap to include elsewhere. The atomic_t helper function definitions
are particularly large, so it's better to move the helpers using those
into the existing linux/mm_inline.h and only include that where needed.
As a follow-up, we may want to go through all the indirect includes in
mm_types.h and reduce them as much as possible.
Link: https://lkml.kernel.org/r/20211207125710.2503446-2-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Colin Cross <ccross@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The patch to add anonymous vma names causes a build failure in some
configurations:
include/linux/mm_types.h: In function 'is_same_vma_anon_name':
include/linux/mm_types.h:924:37: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
924 | return name && vma_name && !strcmp(name, vma_name);
| ^~~~~~
include/linux/mm_types.h:22:1: note: 'strcmp' is defined in header '<string.h>'; did you forget to '#include <string.h>'?
This should not really be part of linux/mm_types.h in the first place,
as that header is meant to only contain structure defintions and need a
minimum set of indirect includes itself.
While the header clearly includes more than it should at this point,
let's not make it worse by including string.h as well, which would pull
in the expensive (compile-speed wise) fortify-string logic.
Move the new functions into a separate header that only needs to be
included in a couple of locations.
Link: https://lkml.kernel.org/r/20211207125710.2503446-1-arnd@kernel.org
Fixes: "mm: add a field to store names for private anonymous memory"
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Colin Cross <ccross@google.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While forking a process with high number (64K) of named anonymous vmas
the overhead caused by strdup() is noticeable. Experiments with ARM64
Android device show up to 40% performance regression when forking a
process with 64k unpopulated anonymous vmas using the max name lengths
vs the same process with the same number of anonymous vmas having no
name.
Introduce anon_vma_name refcounted structure to avoid the overhead of
copying vma names during fork() and when splitting named anonymous vmas.
When a vma is duplicated, instead of copying the name we increment the
refcount of this structure. Multiple vmas can point to the same
anon_vma_name as long as they increment the refcount. The name member
of anon_vma_name structure is assigned at structure allocation time and
is never changed. If vma name changes then the refcount of the original
structure is dropped, a new anon_vma_name structure is allocated to hold
the new name and the vma pointer is updated to point to the new
structure.
With this approach the fork() performance regressions is reduced 3-4x
times and with usecases using more reasonable number of VMAs (a few
thousand) the regressions is not measurable.
Link: https://lkml.kernel.org/r/20211019215511.3771969-3-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Colin Cross <ccross@google.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Glauber <jan.glauber@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Landley <rob@landley.net>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Shaohua Li <shli@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In many userspace applications, and especially in VM based applications
like Android uses heavily, there are multiple different allocators in
use. At a minimum there is libc malloc and the stack, and in many cases
there are libc malloc, the stack, direct syscalls to mmap anonymous
memory, and multiple VM heaps (one for small objects, one for big
objects, etc.). Each of these layers usually has its own tools to
inspect its usage; malloc by compiling a debug version, the VM through
heap inspection tools, and for direct syscalls there is usually no way
to track them.
On Android we heavily use a set of tools that use an extended version of
the logic covered in Documentation/vm/pagemap.txt to walk all pages
mapped in userspace and slice their usage by process, shared (COW) vs.
unique mappings, backing, etc. This can account for real physical
memory usage even in cases like fork without exec (which Android uses
heavily to share as many private COW pages as possible between
processes), Kernel SamePage Merging, and clean zero pages. It produces
a measurement of the pages that only exist in that process (USS, for
unique), and a measurement of the physical memory usage of that process
with the cost of shared pages being evenly split between processes that
share them (PSS).
If all anonymous memory is indistinguishable then figuring out the real
physical memory usage (PSS) of each heap requires either a pagemap
walking tool that can understand the heap debugging of every layer, or
for every layer's heap debugging tools to implement the pagemap walking
logic, in which case it is hard to get a consistent view of memory
across the whole system.
Tracking the information in userspace leads to all sorts of problems.
It either needs to be stored inside the process, which means every
process has to have an API to export its current heap information upon
request, or it has to be stored externally in a filesystem that somebody
needs to clean up on crashes. It needs to be readable while the process
is still running, so it has to have some sort of synchronization with
every layer of userspace. Efficiently tracking the ranges requires
reimplementing something like the kernel vma trees, and linking to it
from every layer of userspace. It requires more memory, more syscalls,
more runtime cost, and more complexity to separately track regions that
the kernel is already tracking.
This patch adds a field to /proc/pid/maps and /proc/pid/smaps to show a
userspace-provided name for anonymous vmas. The names of named
anonymous vmas are shown in /proc/pid/maps and /proc/pid/smaps as
[anon:<name>].
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name)
Setting the name to NULL clears it. The name length limit is 80 bytes
including NUL-terminator and is checked to contain only printable ascii
characters (including space), except '[',']','\','$' and '`'.
Ascii strings are being used to have a descriptive identifiers for vmas,
which can be understood by the users reading /proc/pid/maps or
/proc/pid/smaps. Names can be standardized for a given system and they
can include some variable parts such as the name of the allocator or a
library, tid of the thread using it, etc.
The name is stored in a pointer in the shared union in vm_area_struct
that points to a null terminated string. Anonymous vmas with the same
name (equivalent strings) and are otherwise mergeable will be merged.
The name pointers are not shared between vmas even if they contain the
same name. The name pointer is stored in a union with fields that are
only used on file-backed mappings, so it does not increase memory usage.
CONFIG_ANON_VMA_NAME kernel configuration is introduced to enable this
feature. It keeps the feature disabled by default to prevent any
additional memory overhead and to avoid confusing procfs parsers on
systems which are not ready to support named anonymous vmas.
The patch is based on the original patch developed by Colin Cross, more
specifically on its latest version [1] posted upstream by Sumit Semwal.
It used a userspace pointer to store vma names. In that design, name
pointers could be shared between vmas. However during the last
upstreaming attempt, Kees Cook raised concerns [2] about this approach
and suggested to copy the name into kernel memory space, perform
validity checks [3] and store as a string referenced from
vm_area_struct.
One big concern is about fork() performance which would need to strdup
anonymous vma names. Dave Hansen suggested experimenting with
worst-case scenario of forking a process with 64k vmas having longest
possible names [4]. I ran this experiment on an ARM64 Android device
and recorded a worst-case regression of almost 40% when forking such a
process.
This regression is addressed in the followup patch which replaces the
pointer to a name with a refcounted structure that allows sharing the
name pointer between vmas of the same name. Instead of duplicating the
string during fork() or when splitting a vma it increments the refcount.
[1] https://lore.kernel.org/linux-mm/20200901161459.11772-4-sumit.semwal@linaro.org/
[2] https://lore.kernel.org/linux-mm/202009031031.D32EF57ED@keescook/
[3] https://lore.kernel.org/linux-mm/202009031022.3834F692@keescook/
[4] https://lore.kernel.org/linux-mm/5d0358ab-8c47-2f5f-8e43-23b89d6a8e95@intel.com/
Changes for prctl(2) manual page (in the options section):
PR_SET_VMA
Sets an attribute specified in arg2 for virtual memory areas
starting from the address specified in arg3 and spanning the
size specified in arg4. arg5 specifies the value of the attribute
to be set. Note that assigning an attribute to a virtual memory
area might prevent it from being merged with adjacent virtual
memory areas due to the difference in that attribute's value.
Currently, arg2 must be one of:
PR_SET_VMA_ANON_NAME
Set a name for anonymous virtual memory areas. arg5 should
be a pointer to a null-terminated string containing the
name. The name length including null byte cannot exceed
80 bytes. If arg5 is NULL, the name of the appropriate
anonymous virtual memory areas will be reset. The name
can contain only printable ascii characters (including
space), except '[',']','\','$' and '`'.
This feature is available only if the kernel is built with
the CONFIG_ANON_VMA_NAME option enabled.
[surenb@google.com: docs: proc.rst: /proc/PID/maps: fix malformed table]
Link: https://lkml.kernel.org/r/20211123185928.2513763-1-surenb@google.com
[surenb: rebased over v5.15-rc6, replaced userpointer with a kernel copy,
added input sanitization and CONFIG_ANON_VMA_NAME config. The bulk of the
work here was done by Colin Cross, therefore, with his permission, keeping
him as the author]
Link: https://lkml.kernel.org/r/20211019215511.3771969-2-surenb@google.com
Signed-off-by: Colin Cross <ccross@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jan Glauber <jan.glauber@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Landley <rob@landley.net>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: Shaohua Li <shli@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: rearrange madvise code to allow for reuse", v11.
Avoid performance regression of the new anon vma name field refcounting it.
I checked the image sizes with allnoconfig builds:
unpatched Linus' ToT
text data bss dec hex filename
1324759 32 73928 1398719 1557bf vmlinux
After the first patch is applied (madvise refactoring)
text data bss dec hex filename
1322346 32 73928 1396306 154e52 vmlinux
>>> 2413 bytes decrease vs ToT <<<
After all patches applied with CONFIG_ANON_VMA_NAME=n
text data bss dec hex filename
1322337 32 73928 1396297 154e49 vmlinux
>>> 2422 bytes decrease vs ToT <<<
After all patches applied with CONFIG_ANON_VMA_NAME=y
text data bss dec hex filename
1325228 32 73928 1399188 155994 vmlinux
>>> 469 bytes increase vs ToT <<<
This patch (of 3):
Refactor the madvise syscall to allow for parts of it to be reused by a
prctl syscall that affects vmas.
Move the code that walks vmas in a virtual address range into a function
that takes a function pointer as a parameter. The only caller for now
is sys_madvise, which uses it to call madvise_vma_behavior on each vma,
but the next patch will add an additional caller.
Move handling all vma behaviors inside madvise_behavior, and rename it
to madvise_vma_behavior.
Move the code that updates the flags on a vma, including splitting or
merging the vma as necessary, into a new function called
madvise_update_vma. The next patch will add support for updating a new
anon_name field as well.
Link: https://lkml.kernel.org/r/20211019215511.3771969-1-surenb@google.com
Signed-off-by: Colin Cross <ccross@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jan Glauber <jan.glauber@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Rob Landley <rob@landley.net>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kvmalloc* allocation functions can fallback to vmalloc allocations
and more often on long running machines. In addition the kernel does
have __GFP_ACCOUNT kvmalloc* calls. So, often on long running machines,
the memory.stat does not tell the complete picture which type of memory
is charged to the memcg. So add a per-memcg vmalloc stat.
[shakeelb@google.com: page_memcg() within rcu lock, per Muchun]
Link: https://lkml.kernel.org/r/20211222052457.1960701-1-shakeelb@google.com
[akpm@linux-foundation.org: remove cast, per Muchun]
[shakeelb@google.com: remove area->page[0] checks and move to page by page accounting per Michal]
Link: https://lkml.kernel.org/r/20220104222341.3972772-1-shakeelb@google.com
Link: https://lkml.kernel.org/r/20211221215336.1922823-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.
Link: https://github.com/KSPP/linux/issues/160
Link: https://lkml.kernel.org/r/20211216022024.127375-1-wangweiyang2@huawei.com
Signed-off-by: Wang Weiyang <wangweiyang2@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 11192d9c12 ("memcg: flush stats only if updated") added
tracking of memcg stats updates which is used by the readers to flush
only if the updates are over a certain threshold. However each
individual update can correspond to a large value change for a given
stat. For example adding or removing a hugepage to an LRU changes the
stat by thp_nr_pages (512 on x86_64).
Treating the update related to THP as one can keep the stat off, in
theory, by (thp_nr_pages * nr_cpus * CHARGE_BATCH) before flush.
To handle such scenarios, this patch adds consideration of the stat
update value as well instead of just the update event. In addition let
the asyn flusher unconditionally flush the stats to put time limit on
the stats skew and hopefully a lot less readers would need to flush.
Link: https://lkml.kernel.org/r/20211118065350.697046-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Michal Koutný" <mkoutny@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Our container agent wants to know when a container exits if it was OOM
killed or not to report to the user. We use memory.oom.group = 1 to
ensure that OOM kills within the container's cgroup kill everything.
Existing memory.events are insufficient for knowing if this triggered:
1) Our current approach reads memory.events oom_kill and reports the
container was killed if the value is non-zero. This is erroneous in
some cases where containers create their children cgroups with
memory.oom.group=1 as such OOM kills will get counted against the
container cgroup's oom_kill counter despite not actually OOM killing
the entire container.
2) Reading memory.events.local will fail to identify OOM kills in leaf
cgroups (that don't set memory.oom.group) within the container
cgroup.
This patch adds a new oom_group_kill event when memory.oom.group
triggers to allow userspace to cleanly identify when an entire cgroup is
oom killed.
[schatzberg.dan@gmail.com: changes from Johannes and Chris]
Link: https://lkml.kernel.org/r/20211213162511.2492267-1-schatzberg.dan@gmail.com
Link: https://lkml.kernel.org/r/20211203162426.3375036-1-schatzberg.dan@gmail.com
Signed-off-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
propagate_protected_usage() is called to propagate the usage change in
the page_counter structure. But there is a call to this function from
page_counter_try_charge() when there is actually no usage change. Hence
this call should be removed.
Link: https://lkml.kernel.org/r/20211118181125.3918222-1-dqiao@redhat.com
Signed-off-by: Donghai Qiao <dqiao@redhat.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 494c1dfe85 ("mm: memcg/slab: create a new set of kmalloc-cg-<n>
caches") makes cgroup_memory_nokmem global, however, it is unnecessary
because there is already a function mem_cgroup_kmem_disabled() which
exports it.
Just make it static and replace it with mem_cgroup_kmem_disabled() in
mm/slab_common.c.
Link: https://lkml.kernel.org/r/20211109065418.21693-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Chris Down <chris@chrisdown.name>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'a' and 'b' bitmaps are local to this function, so no concurrent
access can occur. So the non-atomic '__set_bit()' can be used to save a
few cycles.
Link: https://lkml.kernel.org/r/e52476da5cee57151745c5c3c934a69798dc6fa4.1638132190.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a data race in commit 779750d20b ("shmem: split huge pages beyond
i_size under memory pressure").
Here are call traces causing race:
Call Trace 1:
shmem_unused_huge_shrink+0x3ae/0x410
? __list_lru_walk_one.isra.5+0x33/0x160
super_cache_scan+0x17c/0x190
shrink_slab.part.55+0x1ef/0x3f0
shrink_node+0x10e/0x330
kswapd+0x380/0x740
kthread+0xfc/0x130
? mem_cgroup_shrink_node+0x170/0x170
? kthread_create_on_node+0x70/0x70
ret_from_fork+0x1f/0x30
Call Trace 2:
shmem_evict_inode+0xd8/0x190
evict+0xbe/0x1c0
do_unlinkat+0x137/0x330
do_syscall_64+0x76/0x120
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
A simple explanation:
Image there are 3 items in the local list (@list). In the first
traversal, A is not deleted from @list.
1) A->B->C
^
|
pos (leave)
In the second traversal, B is deleted from @list. Concurrently, A is
deleted from @list through shmem_evict_inode() since last reference
counter of inode is dropped by other thread. Then the @list is corrupted.
2) A->B->C
^ ^
| |
evict pos (drop)
We should make sure the inode is either on the global list or deleted from
any local list before iput().
Fixed by moving inodes back to global list before we put them.
[akpm@linux-foundation.org: coding style fixes]
Link: https://lkml.kernel.org/r/20211125064502.99983-1-ligang.bdlg@bytedance.com
Fixes: 779750d20b ("shmem: split huge pages beyond i_size under memory pressure")
Signed-off-by: Gang Li <ligang.bdlg@bytedance.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current behavior of memory failure is to truncate the page cache
regardless of dirty or clean. If the page is dirty the later access
will get the obsolete data from disk without any notification to the
users. This may cause silent data loss. It is even worse for shmem
since shmem is in-memory filesystem, truncating page cache means
discarding data blocks. The later read would return all zero.
The right approach is to keep the corrupted page in page cache, any
later access would return error for syscalls or SIGBUS for page fault,
until the file is truncated, hole punched or removed. The regular
storage backed filesystems would be more complicated so this patch is
focused on shmem. This also unblock the support for soft offlining
shmem THP.
[akpm@linux-foundation.org: coding style fixes]
[arnd@arndb.de: fix uninitialized variable use in me_pagecache_clean()]
Link: https://lkml.kernel.org/r/20211022064748.4173718-1-arnd@kernel.org
[Fix invalid pointer dereference in shmem_read_mapping_page_gfp() with a
slight different implementation from what Ajay Garg <ajaygargnsit@gmail.com>
and Muchun Song <songmuchun@bytedance.com> proposed and reworked the
error handling of shmem_write_begin() suggested by Linus]
Link: https://lore.kernel.org/linux-mm/20211111084617.6746-1-ajaygargnsit@gmail.com/
Link: https://lkml.kernel.org/r/20211020210755.23964-6-shy828301@gmail.com
Link: https://lkml.kernel.org/r/20211116193247.21102-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ajay Garg <ajaygargnsit@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Andy Lavr <andy.lavr@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When BUG_ON check for THP migration entry, the existing code only check
thp_migration_supported case, but not for !thp_migration_supported case.
If !thp_migration_supported() and !pmd_present(), the original code may
dead loop in theory. To make the BUG_ON check consistent, we need catch
both cases.
Move the BUG_ON check one step earlier, because if the bug happen we
should know it instead of depend on FOLL_MIGRATION been used by caller.
Because pmdval instead of *pmd is read by the is_pmd_migration_entry()
check, the existing code don't help to avoid useless locking within
pmd_migration_entry_wait(), so remove that check.
Link: https://lkml.kernel.org/r/20211217062559.737063-1-lixinhai.lxh@gmail.com
Signed-off-by: Li Xinhai <lixinhai.lxh@gmail.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fault_in_readable() and fault_in_writeable() perform __get_user() and
__put_user() in a loop, implying multiple user access locking/unlocking.
To avoid that, use user access blocks.
Link: https://lkml.kernel.org/r/720dcf79314acca1a78fae56d478cc851952149d.1637084492.git.christophe.leroy@csgroup.eu
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Return value directly instead of taking this in another redundant
variable.
Link: https://lkml.kernel.org/r/20211207083222.401594-1-chi.minghao@zte.com.cn
Signed-off-by: chiminghao <chi.minghao@zte.com.cn>
Reported-by: Zeal Robot <zealci@zte.com.cm>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dump_mapping() is a big chunk of dump_page(), and it'd be handy to be
able to call it when we don't have a struct page. Split it out and move
it to fs/inode.c. Take the opportunity to simplify some of the debug
messages a little.
Link: https://lkml.kernel.org/r/20211121121056.2870061-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KASAN's quarantine might save its metadata inside freed objects. As
this happens after the memory is zeroed by the slab allocator when
init_on_free is enabled, the memory coming out of quarantine is not
properly zeroed.
This causes lib/test_meminit.c tests to fail with Generic KASAN.
Zero the metadata when the object is removed from quarantine.
Link: https://lkml.kernel.org/r/2805da5df4b57138fdacd671f5d227d58950ba54.1640037083.git.andreyknvl@google.com
Fixes: 6471384af2 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because mm/slab_common.c is not instrumented with software KASAN modes,
it is not possible to detect use-after-free of the kmem_cache passed
into kmem_cache_destroy(). In particular, because of the s->refcount--
and subsequent early return if non-zero, KASAN would never be able to
see the double-free via kmem_cache_free(kmem_cache, s). To be able to
detect a double-kmem_cache_destroy(), check accessibility of the
kmem_cache, and in case of failure return early.
While KASAN_HW_TAGS is able to detect such bugs, by checking
accessibility and returning early we fail more gracefully and also avoid
corrupting reused objects (where tags mismatch).
A recent case of a double-kmem_cache_destroy() was detected by KFENCE:
https://lkml.kernel.org/r/0000000000003f654905c168b09d@google.com, which
was not detectable by software KASAN modes.
Link: https://lkml.kernel.org/r/20211119142219.1519617-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a new @vmemmap_shift property for struct dev_pagemap which specifies
that a devmap is composed of a set of compound pages of order
@vmemmap_shift, instead of base pages. When a compound page devmap is
requested, all but the first page are initialised as tail pages instead
of order-0 pages.
For certain ZONE_DEVICE users like device-dax which have a fixed page
size, this creates an opportunity to optimize GUP and GUP-fast walkers,
treating it the same way as THP or hugetlb pages.
Additionally, commit 7118fc2906 ("hugetlb: address ref count racing in
prep_compound_gigantic_page") removed set_page_count() because the
setting of page ref count to zero was redundant. devmap pages don't
come from page allocator though and only head page refcount is used for
compound pages, hence initialize tail page count to zero.
Link: https://lkml.kernel.org/r/20211202204422.26777-5-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move struct page init to an helper function __init_zone_device_page().
This is in preparation for sharing the storage for compound page
metadata.
Link: https://lkml.kernel.org/r/20211202204422.26777-4-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm, device-dax: Introduce compound pages in devmap", v7.
This series converts device-dax to use compound pages, and moves away
from the 'struct page per basepage on PMD/PUD' that is done today.
Doing so
1) unlocks a few noticeable improvements on unpin_user_pages() and
makes device-dax+altmap case 4x times faster in pinning (numbers
below and in last patch)
2) as mentioned in various other threads it's one important step
towards cleaning up ZONE_DEVICE refcounting.
I've split the compound pages on devmap part from the rest based on
recent discussions on devmap pending and future work planned[5][6].
There is consensus that device-dax should be using compound pages to
represent its PMD/PUDs just like HugeTLB and THP, and that leads to less
specialization of the dax parts. I will pursue the rest of the work in
parallel once this part is merged, particular the GUP-{slow,fast}
improvements [7] and the tail struct page deduplication memory savings
part[8].
To summarize what the series does:
Patch 1: Prepare hwpoisoning to work with dax compound pages.
Patches 2-3: Split the current utility function of prep_compound_page()
into head and tail and use those two helpers where appropriate to take
advantage of caches being warm after __init_single_page(). This is used
when initializing zone device when we bring up device-dax namespaces.
Patches 4-10: Add devmap support for compound pages in device-dax.
memmap_init_zone_device() initialize its metadata as compound pages, and
it introduces a new devmap property known as vmemmap_shift which
outlines how the vmemmap is structured (defaults to base pages as done
today). The property describe the page order of the metadata
essentially. While at it do a few cleanups in device-dax in patches
5-9. Finally enable device-dax usage of devmap @vmemmap_shift to a
value based on its own @align property. @vmemmap_shift returns 0 by
default (which is today's case of base pages in devmap, like fsdax or
the others) and the usage of compound devmap is optional. Starting with
device-dax (*not* fsdax) we enable it by default. There are a few
pinning improvements particular on the unpinning case and altmap, as
well as unpin_user_page_range_dirty_lock() being just as effective as
THP/hugetlb[0] pages.
$ gup_test -f /dev/dax1.0 -m 16384 -r 10 -S -a -n 512 -w
(pin_user_pages_fast 2M pages) put:~71 ms -> put:~22 ms
[altmap]
(pin_user_pages_fast 2M pages) get:~524ms put:~525 ms -> get: ~127ms put:~71ms
$ gup_test -f /dev/dax1.0 -m 129022 -r 10 -S -a -n 512 -w
(pin_user_pages_fast 2M pages) put:~513 ms -> put:~188 ms
[altmap with -m 127004]
(pin_user_pages_fast 2M pages) get:~4.1 secs put:~4.12 secs -> get:~1sec put:~563ms
Tested on x86 with 1Tb+ of pmem (alongside registering it with RDMA with
and without altmap), alongside gup_test selftests with dynamic dax
regions and static dax regions. Coupled with ndctl unit tests for
dynamic dax devices that exercise all of this. Note, for dynamic dax
regions I had to revert commit 8aa83e6395 ("x86/setup: Call
early_reserve_memory() earlier"), it is a known issue that this commit
broke efi_fake_mem=.
This patch (of 11):
Split the utility function prep_compound_page() into head and tail
counterparts, and use them accordingly.
This is in preparation for sharing the storage for compound page
metadata.
Link: https://lkml.kernel.org/r/20211202204422.26777-1-joao.m.martins@oracle.com
Link: https://lkml.kernel.org/r/20211202204422.26777-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yongqiang reports a kmemleak panic when module insmod/rmmod with KASAN
enabled(without KASAN_VMALLOC) on x86[1].
When the module area allocates memory, it's kmemleak_object is created
successfully, but the KASAN shadow memory of module allocation is not
ready, so when kmemleak scan the module's pointer, it will panic due to
no shadow memory with KASAN check.
module_alloc
__vmalloc_node_range
kmemleak_vmalloc
kmemleak_scan
update_checksum
kasan_module_alloc
kmemleak_ignore
Note, there is no problem if KASAN_VMALLOC enabled, the modules area
entire shadow memory is preallocated. Thus, the bug only exits on ARCH
which supports dynamic allocation of module area per module load, for
now, only x86/arm64/s390 are involved.
Add a VM_DEFER_KMEMLEAK flags, defer vmalloc'ed object register of
kmemleak in module_alloc() to fix this issue.
[1] https://lore.kernel.org/all/6d41e2b9-4692-5ec4-b1cd-cbe29ae89739@huawei.com/
[wangkefeng.wang@huawei.com: fix build]
Link: https://lkml.kernel.org/r/20211125080307.27225-1-wangkefeng.wang@huawei.com
[akpm@linux-foundation.org: simplify ifdefs, per Andrey]
Link: https://lkml.kernel.org/r/CA+fCnZcnwJHUQq34VuRxpdoY6_XbJCDJ-jopksS5Eia4PijPzw@mail.gmail.com
Link: https://lkml.kernel.org/r/20211124142034.192078-1-wangkefeng.wang@huawei.com
Fixes: 793213a82d ("s390/kasan: dynamic shadow mem allocation for modules")
Fixes: 39d114ddc6 ("arm64: add KASAN support")
Fixes: bebf56a1b1 ("kasan: enable instrumentation of global variables")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reported-by: Yongqiang Liu <liuyongqiang13@huawei.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With HW tag-based kasan enable, We will get the warning when we free
object whose address starts with 0xFF.
It is because kmemleak rbtree stores tagged object and this freeing
object's tag does not match with rbtree object.
In the example below, kmemleak rbtree stores the tagged object in the
kmalloc(), and kfree() gets the pointer with 0xFF tag.
Call sequence:
ptr = kmalloc(size, GFP_KERNEL);
page = virt_to_page(ptr);
offset = offset_in_page(ptr);
kfree(page_address(page) + offset);
ptr = kmalloc(size, GFP_KERNEL);
A sequence like that may cause the warning as following:
1) Freeing unknown object:
In kfree(), we will get free unknown object warning in
kmemleak_free(). Because object(0xFx) in kmemleak rbtree and
pointer(0xFF) in kfree() have different tag.
2) Overlap existing:
When we allocate that object with the same hw-tag again, we will
find the overlap in the kmemleak rbtree and kmemleak thread will be
killed.
kmemleak: Freeing unknown object at 0xffff000003f88000
CPU: 5 PID: 177 Comm: cat Not tainted 5.16.0-rc1-dirty #21
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x1ac
show_stack+0x1c/0x30
dump_stack_lvl+0x68/0x84
dump_stack+0x1c/0x38
kmemleak_free+0x6c/0x70
slab_free_freelist_hook+0x104/0x200
kmem_cache_free+0xa8/0x3d4
test_version_show+0x270/0x3a0
module_attr_show+0x28/0x40
sysfs_kf_seq_show+0xb0/0x130
kernfs_seq_show+0x30/0x40
seq_read_iter+0x1bc/0x4b0
seq_read_iter+0x1bc/0x4b0
kernfs_fop_read_iter+0x144/0x1c0
generic_file_splice_read+0xd0/0x184
do_splice_to+0x90/0xe0
splice_direct_to_actor+0xb8/0x250
do_splice_direct+0x88/0xd4
do_sendfile+0x2b0/0x344
__arm64_sys_sendfile64+0x164/0x16c
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0x44/0xec
do_el0_svc+0x74/0x90
el0_svc+0x20/0x80
el0t_64_sync_handler+0x1a8/0x1b0
el0t_64_sync+0x1ac/0x1b0
...
kmemleak: Cannot insert 0xf2ff000003f88000 into the object search tree (overlaps existing)
CPU: 5 PID: 178 Comm: cat Not tainted 5.16.0-rc1-dirty #21
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x1ac
show_stack+0x1c/0x30
dump_stack_lvl+0x68/0x84
dump_stack+0x1c/0x38
create_object.isra.0+0x2d8/0x2fc
kmemleak_alloc+0x34/0x40
kmem_cache_alloc+0x23c/0x2f0
test_version_show+0x1fc/0x3a0
module_attr_show+0x28/0x40
sysfs_kf_seq_show+0xb0/0x130
kernfs_seq_show+0x30/0x40
seq_read_iter+0x1bc/0x4b0
kernfs_fop_read_iter+0x144/0x1c0
generic_file_splice_read+0xd0/0x184
do_splice_to+0x90/0xe0
splice_direct_to_actor+0xb8/0x250
do_splice_direct+0x88/0xd4
do_sendfile+0x2b0/0x344
__arm64_sys_sendfile64+0x164/0x16c
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0x44/0xec
do_el0_svc+0x74/0x90
el0_svc+0x20/0x80
el0t_64_sync_handler+0x1a8/0x1b0
el0t_64_sync+0x1ac/0x1b0
kmemleak: Kernel memory leak detector disabled
kmemleak: Object 0xf2ff000003f88000 (size 128):
kmemleak: comm "cat", pid 177, jiffies 4294921177
kmemleak: min_count = 1
kmemleak: count = 0
kmemleak: flags = 0x1
kmemleak: checksum = 0
kmemleak: backtrace:
kmem_cache_alloc+0x23c/0x2f0
test_version_show+0x1fc/0x3a0
module_attr_show+0x28/0x40
sysfs_kf_seq_show+0xb0/0x130
kernfs_seq_show+0x30/0x40
seq_read_iter+0x1bc/0x4b0
kernfs_fop_read_iter+0x144/0x1c0
generic_file_splice_read+0xd0/0x184
do_splice_to+0x90/0xe0
splice_direct_to_actor+0xb8/0x250
do_splice_direct+0x88/0xd4
do_sendfile+0x2b0/0x344
__arm64_sys_sendfile64+0x164/0x16c
invoke_syscall+0x48/0x114
el0_svc_common.constprop.0+0x44/0xec
do_el0_svc+0x74/0x90
kmemleak: Automatic memory scanning thread ended
[akpm@linux-foundation.org: whitespace tweak]
Link: https://lkml.kernel.org/r/20211118054426.4123-1-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Doug Berger <opendmb@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no external users of slab_start/next/stop(), so make them
static. And the memory.kmem.slabinfo is deprecated, which outputs
nothing now, so move memcg_slab_show() into mm/memcontrol.c and rename
it to mem_cgroup_slab_show to be consistent with other function names.
Link: https://lkml.kernel.org/r/20211109133359.32881-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Calling kmem_cache_destroy() while the cache still has objects allocated
is a kernel bug, and will usually result in the entire cache being
leaked. While the message in kmem_cache_destroy() resembles a warning,
it is currently not implemented using a real WARN().
This is problematic for infrastructure testing the kernel, all of which
rely on the specific format of WARN()s to pick up on bugs.
Some 13 years ago this used to be a simple WARN_ON() in slub, but commit
d629d81957 ("slub: improve kmem_cache_destroy() error message")
changed it into an open-coded warning to avoid confusion with a bug in
slub itself.
Instead, turn the open-coded warning into a real WARN() with the message
preserved, so that test systems can actually identify these issues, and
we get all the other benefits of using a normal WARN(). The warning
message is extended with "when called from <caller-ip>" to make it even
clearer where the fault lies.
For most configurations this is only a cosmetic change, however, note
that WARN() here will now also respect panic_on_warn.
Link: https://lkml.kernel.org/r/20211102170733.648216-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Simplify the dax_operations API
- Eliminate bdev_dax_pgoff() in favor of the filesystem maintaining
and applying a partition offset to all its DAX iomap operations.
- Remove wrappers and device-mapper stacked callbacks for
->copy_from_iter() and ->copy_to_iter() in favor of moving
block_device relative offset responsibility to the
dax_direct_access() caller.
- Remove the need for an @bdev in filesystem-DAX infrastructure
- Remove unused uio helpers copy_from_iter_flushcache() and
copy_mc_to_iter() as only the non-check_copy_size() versions are
used for DAX.
- Prepare XFS for the pending (next merge window) DAX+reflink support
- Remove deprecated DEV_DAX_PMEM_COMPAT support
- Cleanup a straggling misuse of the GUID api
Tags offered after the branch was cut:
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/Ydb/3P+8nvjCjYfO@redhat.com
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Merge tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull dax and libnvdimm updates from Dan Williams:
"The bulk of this is a rework of the dax_operations API after
discovering the obstacles it posed to the work-in-progress DAX+reflink
support for XFS and other copy-on-write filesystem mechanics.
Primarily the need to plumb a block_device through the API to handle
partition offsets was a sticking point and Christoph untangled that
dependency in addition to other cleanups to make landing the
DAX+reflink support easier.
The DAX_PMEM_COMPAT option has been around for 4 years and not only
are distributions shipping userspace that understand the current
configuration API, but some are not even bothering to turn this option
on anymore, so it seems a good time to remove it per the deprecation
schedule. Recall that this was added after the device-dax subsystem
moved from /sys/class/dax to /sys/bus/dax for its sysfs organization.
All recent functionality depends on /sys/bus/dax.
Some other miscellaneous cleanups and reflink prep patches are
included as well.
Summary:
- Simplify the dax_operations API:
- Eliminate bdev_dax_pgoff() in favor of the filesystem
maintaining and applying a partition offset to all its DAX iomap
operations.
- Remove wrappers and device-mapper stacked callbacks for
->copy_from_iter() and ->copy_to_iter() in favor of moving
block_device relative offset responsibility to the
dax_direct_access() caller.
- Remove the need for an @bdev in filesystem-DAX infrastructure
- Remove unused uio helpers copy_from_iter_flushcache() and
copy_mc_to_iter() as only the non-check_copy_size() versions are
used for DAX.
- Prepare XFS for the pending (next merge window) DAX+reflink support
- Remove deprecated DEV_DAX_PMEM_COMPAT support
- Cleanup a straggling misuse of the GUID api"
* tag 'libnvdimm-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (38 commits)
iomap: Fix error handling in iomap_zero_iter()
ACPI: NFIT: Import GUID before use
dax: remove the copy_from_iter and copy_to_iter methods
dax: remove the DAXDEV_F_SYNC flag
dax: simplify dax_synchronous and set_dax_synchronous
uio: remove copy_from_iter_flushcache() and copy_mc_to_iter()
iomap: turn the byte variable in iomap_zero_iter into a ssize_t
memremap: remove support for external pgmap refcounts
fsdax: don't require CONFIG_BLOCK
iomap: build the block based code conditionally
dax: fix up some of the block device related ifdefs
fsdax: shift partition offset handling into the file systems
dax: return the partition offset from fs_dax_get_by_bdev
iomap: add a IOMAP_DAX flag
xfs: pass the mapping flags to xfs_bmbt_to_iomap
xfs: use xfs_direct_write_iomap_ops for DAX zeroing
xfs: move dax device handling into xfs_{alloc,free}_buftarg
ext4: cleanup the dax handling in ext4_fill_super
ext2: cleanup the dax handling in ext2_fill_super
fsdax: decouple zeroing from the iomap buffered I/O code
...
This patchset stops just short of actually enabling large folios.
It converts everything that I noticed needs to be converted, but there may
still be places I've overlooked which still have page size assumptions.
The big change here is using large entries in the page cache XArray
instead of many small entries. That only affects shmem for now, but
it's a pretty big change for shmem since it changes where memory needs
to be allocated (at split time instead of insertion).
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Merge tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache
Pull folio conversion updates from Matthew Wilcox:
"Convert much of the page cache to use folios
This stops just short of actually enabling large folios. It converts
everything that I noticed needs to be converted, but there may still
be places I've overlooked which still have page size assumptions.
The big change here is using large entries in the page cache XArray
instead of many small entries. That only affects shmem for now, but
it's a pretty big change for shmem since it changes where memory needs
to be allocated (at split time instead of insertion)"
* tag 'folio-5.17' of git://git.infradead.org/users/willy/pagecache: (49 commits)
mm: Use multi-index entries in the page cache
XArray: Add xas_advance()
truncate,shmem: Handle truncates that split large folios
truncate: Convert invalidate_inode_pages2_range to folios
fs: Convert vfs_dedupe_file_range_compare to folios
mm: Remove pagevec_remove_exceptionals()
mm: Convert find_lock_entries() to use a folio_batch
filemap: Return only folios from find_get_entries()
filemap: Convert filemap_get_read_batch() to use a folio_batch
filemap: Convert filemap_read() to use a folio
truncate: Add invalidate_complete_folio2()
truncate: Convert invalidate_inode_pages2_range() to use a folio
truncate: Skip known-truncated indices
truncate,shmem: Add truncate_inode_folio()
shmem: Convert part of shmem_undo_range() to use a folio
mm: Add unmap_mapping_folio()
truncate: Add truncate_cleanup_folio()
filemap: Add filemap_release_folio()
filemap: Use a folio in filemap_page_mkwrite
filemap: Use a folio in filemap_map_pages
...
This series provides KCSAN fixes and also the ability to take memory
barriers into account for weakly-ordered systems. This last can increase
the probability of detecting certain types of data races.
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Merge tag 'kcsan.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull KCSAN updates from Paul McKenney:
"This provides KCSAN fixes and also the ability to take memory barriers
into account for weakly-ordered systems. This last can increase the
probability of detecting certain types of data races"
* tag 'kcsan.2022.01.09a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (29 commits)
kcsan: Only test clear_bit_unlock_is_negative_byte if arch defines it
kcsan: Avoid nested contexts reading inconsistent reorder_access
kcsan: Turn barrier instrumentation into macros
kcsan: Make barrier tests compatible with lockdep
kcsan: Support WEAK_MEMORY with Clang where no objtool support exists
compiler_attributes.h: Add __disable_sanitizer_instrumentation
objtool, kcsan: Remove memory barrier instrumentation from noinstr
objtool, kcsan: Add memory barrier instrumentation to whitelist
sched, kcsan: Enable memory barrier instrumentation
mm, kcsan: Enable barrier instrumentation
x86/qspinlock, kcsan: Instrument barrier of pv_queued_spin_unlock()
x86/barriers, kcsan: Use generic instrumentation for non-smp barriers
asm-generic/bitops, kcsan: Add instrumentation for barriers
locking/atomics, kcsan: Add instrumentation for barriers
locking/barriers, kcsan: Support generic instrumentation
locking/barriers, kcsan: Add instrumentation for barriers
kcsan: selftest: Add test case to check memory barrier instrumentation
kcsan: Ignore GCC 11+ warnings about TSan runtime support
kcsan: test: Add test cases for memory barrier instrumentation
kcsan: test: Match reordered or normal accesses
...
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Merge tag 'slab-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- Separate struct slab from struct page - an offshot of the page folio
work.
Struct page fields used by slab allocators are moved from struct page
to a new struct slab, that uses the same physical storage. Similar to
struct folio, it always is a head page. This brings better type
safety, separation of large kmalloc allocations from true slabs, and
cleanup of related objcg code.
- A SLAB_MERGE_DEFAULT config optimization.
* tag 'slab-for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (33 commits)
mm/slob: Remove unnecessary page_mapcount_reset() function call
bootmem: Use page->index instead of page->freelist
zsmalloc: Stop using slab fields in struct page
mm/slub: Define struct slab fields for CONFIG_SLUB_CPU_PARTIAL only when enabled
mm/slub: Simplify struct slab slabs field definition
mm/sl*b: Differentiate struct slab fields by sl*b implementations
mm/kfence: Convert kfence_guarded_alloc() to struct slab
mm/kasan: Convert to struct folio and struct slab
mm/slob: Convert SLOB to use struct slab and struct folio
mm/memcg: Convert slab objcgs from struct page to struct slab
mm: Convert struct page to struct slab in functions used by other subsystems
mm/slab: Finish struct page to struct slab conversion
mm/slab: Convert most struct page to struct slab by spatch
mm/slab: Convert kmem_getpages() and kmem_freepages() to struct slab
mm/slub: Finish struct page to struct slab conversion
mm/slub: Convert most struct page to struct slab by spatch
mm/slub: Convert pfmemalloc_match() to take a struct slab
mm/slub: Convert __free_slab() to use struct slab
mm/slub: Convert alloc_slab_page() to return a struct slab
mm/slub: Convert print_page_info() to print_slab_info()
...
from poison memory and error injection into SGX pages
- A bunch of changes to the SGX selftests to simplify and allow of SGX
features testing without the need of a whole SGX software stack
- Add a sysfs attribute which is supposed to show the amount of SGX
memory in a NUMA node, similar to what /proc/meminfo is to normal
memory
- The usual bunch of fixes and cleanups too
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Merge tag 'x86_sgx_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SGX updates from Borislav Petkov:
- Add support for handling hw errors in SGX pages: poisoning,
recovering from poison memory and error injection into SGX pages
- A bunch of changes to the SGX selftests to simplify and allow of SGX
features testing without the need of a whole SGX software stack
- Add a sysfs attribute which is supposed to show the amount of SGX
memory in a NUMA node, similar to what /proc/meminfo is to normal
memory
- The usual bunch of fixes and cleanups too
* tag 'x86_sgx_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
x86/sgx: Fix NULL pointer dereference on non-SGX systems
selftests/sgx: Fix corrupted cpuid macro invocation
x86/sgx: Add an attribute for the amount of SGX memory in a NUMA node
x86/sgx: Fix minor documentation issues
selftests/sgx: Add test for multiple TCS entry
selftests/sgx: Enable multiple thread support
selftests/sgx: Add page permission and exception test
selftests/sgx: Rename test properties in preparation for more enclave tests
selftests/sgx: Provide per-op parameter structs for the test enclave
selftests/sgx: Add a new kselftest: Unclobbered_vdso_oversubscribed
selftests/sgx: Move setup_test_encl() to each TEST_F()
selftests/sgx: Encpsulate the test enclave creation
selftests/sgx: Dump segments and /proc/self/maps only on failure
selftests/sgx: Create a heap for the test enclave
selftests/sgx: Make data measurement for an enclave segment optional
selftests/sgx: Assign source for each segment
selftests/sgx: Fix a benign linker warning
x86/sgx: Add check for SGX pages to ghes_do_memory_failure()
x86/sgx: Add hook to error injection address validation
x86/sgx: Hook arch_memory_failure() into mainline code
...
When I say remove I mean remove. All profile_task_exit and
profile_munmap do is call a blocking notifier chain. The helpers
profile_task_register and profile_task_unregister are not called
anywhere in the tree. Which means this is all dead code.
So remove the dead code and make it easier to read do_exit.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20220103213312.9144-1-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
In preparation for removing the flag SIGNAL_GROUP_COREDUMP, change
__task_will_free_mem to test signal->core_state instead of the flag
SIGNAL_GROUP_COREDUMP.
Both fields are protected by siglock and both live in signal_struct so
there are no real tradeoffs here, just a change to which field is
being tested.
Link: https://lkml.kernel.org/r/20211213225350.27481-3-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
We currently store large folios as 2^N consecutive entries. While this
consumes rather more memory than necessary, it also turns out to be buggy.
A writeback operation which starts within a tail page of a dirty folio will
not write back the folio as the xarray's dirty bit is only set on the
head index. With multi-index entries, the dirty bit will be found no
matter where in the folio the operation starts.
This does end up simplifying the page cache slightly, although not as
much as I had hoped.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Handle folio splitting in the parts of the truncation functions which
already handle partial pages. Factor all that code out into a new
function called truncate_inode_partial_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
If we're going to unmap a folio, we have to be sure to unmap the entire
folio, not just the part of it which lies after the search index.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
All of its callers now call folio_batch_remove_exceptionals().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
find_lock_entries() already only returned the head page of folios, so
convert it to return a folio_batch instead of a pagevec. That cascades
through converting truncate_inode_pages_range() to
delete_from_page_cache_batch() and page_cache_delete_batch().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
The callers have all been converted to work on folios, so convert
find_get_entries() to return a batch of folios instead of pages.
We also now return multiple large folios in a single call.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This change ripples all the way through the filemap_read() call chain and
removes a lot of messing about converting folios to pages and back again.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
We know the pagevec always contains folios, but use page_folio() anyway
instead of casting. Removes a few calls to legacy functions.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Convert invalidate_complete_page2() to invalidate_complete_folio2().
Use filemap_free_folio() to free the page instead of calling ->freepage
manually.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
If we're going to unmap a folio, we have to be sure to unmap the entire
folio, not just the part of it which lies after the search index.
We cannot yet remove the struct page from invalidate_inode_pages2_range()
because the page pointer in the pvec might be a shadow/dax/swap entry
instead of actually a page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
If we've truncated an entire folio, we can skip over all the indices
covered by this folio.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Convert all callers of truncate_inode_page() to call
truncate_inode_folio() instead, and move the declaration to mm/internal.h.
Move the assertion that the caller is not passing in a tail page to
generic_error_remove_page(). We can't entirely remove the struct page
from the callers yet because the page pointer in the pvec might be a
shadow/dax/swap entry instead of actually a page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
find_lock_entries() never returns tail pages. We cannot use page_folio()
here as the pagevec may also contain swap entries, so simply cast for
now. This is an intermediate step which will be fully removed by the
end of this series.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Convert both callers of unmap_mapping_page() to call unmap_mapping_folio()
instead. Also move zap_details from linux/mm.h to mm/memory.c
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
All members of struct slab can now be removed from struct page.
This shrinks the definition of struct page by 30 LOC, making
it easier to understand.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
After commit 401fb12c68 ("mm/sl*b: Differentiate struct slab fields by
sl*b implementations"), we can reorder fields of struct slab depending
on slab allocator.
For now, page_mapcount_reset() is called because page->_mapcount and
slab->units have same offset. But this is not necessary for struct slab.
Use unused field for units instead.
Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://lore.kernel.org/r/20211212065241.GA886691@odroid
page->freelist is for the use of slab. Using page->index is the same
set of bits as page->freelist, and by using an integer instead of a
pointer, we can avoid casts.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <x86@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
The ->freelist and ->units members of struct page are for the use of
slab only. I'm not particularly familiar with zsmalloc, so generate the
same code by using page->index to store 'page' (page->index and
page->freelist are at the same offset in struct page). This should be
cleaned up properly at some point by somebody who is familiar with
zsmalloc.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
The fields 'next' and 'slabs' are only used when CONFIG_SLUB_CPU_PARTIAL
is enabled. We can put their definition to #ifdef to prevent accidental
use when disabled.
Currenlty show_slab_objects() and slabs_cpu_partial_show() contain code
accessing the slabs field that's effectively dead with
CONFIG_SLUB_CPU_PARTIAL=n through the wrappers slub_percpu_partial() and
slub_percpu_partial_read_once(), but to prevent a compile error, we need
to hide all this code behind #ifdef.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Before commit b47291ef02 ("mm, slub: change percpu partial accounting
from objects to pages") we had to fit two integer fields into a native
word size, so we used short int on 32-bit and int on 64-bit via #ifdef.
After that commit there is only one integer field, so we can simply
define it as int everywhere.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
With a struct slab definition separate from struct page, we can go
further and define only fields that the chosen sl*b implementation uses.
This means everything between __page_flags and __page_refcount
placeholders now depends on the chosen CONFIG_SL*B. Some fields exist in
all implementations (slab_list) but can be part of a union in some, so
it's simpler to repeat them than complicate the definition with ifdefs
even more.
The patch doesn't change physical offsets of the fields, although it
could be done later - for example it's now clear that tighter packing in
SLOB could be possible.
This should also prevent accidental use of fields that don't exist in
given implementation. Before this patch virt_to_cache() and
cache_from_obj() were visible for SLOB (albeit not used), although they
rely on the slab_cache field that isn't set by SLOB. With this patch
it's now a compile error, so these functions are now hidden behind
an #ifndef CONFIG_SLOB.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Marco Elver <elver@google.com> # kfence
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
The function sets some fields that are being moved from struct page to
struct slab so it needs to be converted.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
KASAN accesses some slab related struct page fields so we need to
convert it to struct slab. Some places are a bit simplified thanks to
kasan_addr_to_slab() encapsulating the PageSlab flag check through
virt_to_slab(). When resolving object address to either a real slab or
a large kmalloc, use struct folio as the intermediate type for testing
the slab flag to avoid unnecessary implicit compound_head().
[ vbabka@suse.cz: use struct folio, adjust to differences in previous
patches ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeongogn Yoo <42.hyeyoo@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <kasan-dev@googlegroups.com>
Use struct slab throughout the slob allocator. Where non-slab page can
appear use struct folio instead of struct page.
[ vbabka@suse.cz: don't introduce wrappers for PageSlobFree in mm/slab.h
just for the single callers being wrappers in mm/slob.c ]
[ Hyeonggon Yoo <42.hyeyoo@gmail.com>: fix NULL pointer deference ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
page->memcg_data is used with MEMCG_DATA_OBJCGS flag only for slab pages
so convert all the related infrastructure to struct slab. Also use
struct folio instead of struct page when resolving object pointers.
This is not just mechanistic changing of types and names. Now in
mem_cgroup_from_obj() we use folio_test_slab() to decide if we interpret
the folio as a real slab instead of a large kmalloc, instead of relying
on MEMCG_DATA_OBJCGS bit that used to be checked in page_objcgs_check().
Similarly in memcg_slab_free_hook() where we can encounter
kmalloc_large() pages (here the folio slab flag check is implied by
virt_to_slab()). As a result, page_objcgs_check() can be dropped instead
of converted.
To avoid include cycles, move the inline definition of slab_objcgs()
from memcontrol.h to mm/slab.h.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <cgroups@vger.kernel.org>
Change cache_free_alien() to use slab_nid(virt_to_slab()). Otherwise
just update of comments and some remaining variable names.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
The majority of conversion from struct page to struct slab in SLAB
internals can be delegated to a coccinelle semantic patch. This includes
renaming of variables with 'page' in name to 'slab', and similar.
Big thanks to Julia Lawall and Luis Chamberlain for help with
coccinelle.
// Options: --include-headers --no-includes --smpl-spacing mm/slab.c
// Note: needs coccinelle 1.1.1 to avoid breaking whitespace, and ocaml for the
// embedded script
// build list of functions for applying the next rule
@initialize:ocaml@
@@
let ok_function p =
not (List.mem (List.hd p).current_element ["kmem_getpages";"kmem_freepages"])
// convert the type in selected functions
@@
position p : script:ocaml() { ok_function p };
@@
- struct page@p
+ struct slab
@@
@@
-PageSlabPfmemalloc(page)
+slab_test_pfmemalloc(slab)
@@
@@
-ClearPageSlabPfmemalloc(page)
+slab_clear_pfmemalloc(slab)
@@
@@
obj_to_index(
...,
- page
+ slab_page(slab)
,...)
// for all functions, change any "struct slab *page" parameter to "struct slab
// *slab" in the signature, and generally all occurences of "page" to "slab" in
// the body - with some special cases.
@@
identifier fn;
expression E;
@@
fn(...,
- struct slab *page
+ struct slab *slab
,...)
{
<...
(
- int page_node;
+ int slab_node;
|
- page_node
+ slab_node
|
- page_slab(page)
+ slab
|
- page_address(page)
+ slab_address(slab)
|
- page_size(page)
+ slab_size(slab)
|
- page_to_nid(page)
+ slab_nid(slab)
|
- virt_to_head_page(E)
+ virt_to_slab(E)
|
- page
+ slab
)
...>
}
// rename a function parameter
@@
identifier fn;
expression E;
@@
fn(...,
- int page_node
+ int slab_node
,...)
{
<...
- page_node
+ slab_node
...>
}
// functions converted by previous rules that were temporarily called using
// slab_page(E) so we want to remove the wrapper now that they accept struct
// slab ptr directly
@@
identifier fn =~ "index_to_obj";
expression E;
@@
fn(...,
- slab_page(E)
+ E
,...)
// functions that were returning struct page ptr and now will return struct
// slab ptr, including slab_page() wrapper removal
@@
identifier fn =~ "cache_grow_begin|get_valid_first_slab|get_first_slab";
expression E;
@@
fn(...)
{
<...
- slab_page(E)
+ E
...>
}
// rename any former struct page * declarations
@@
@@
struct slab *
-page
+slab
;
// all functions (with exceptions) with a local "struct slab *page" variable
// that will be renamed to "struct slab *slab"
@@
identifier fn !~ "kmem_getpages|kmem_freepages";
expression E;
@@
fn(...)
{
<...
(
- page_slab(page)
+ slab
|
- page_to_nid(page)
+ slab_nid(slab)
|
- kasan_poison_slab(page)
+ kasan_poison_slab(slab_page(slab))
|
- page_address(page)
+ slab_address(slab)
|
- page_size(page)
+ slab_size(slab)
|
- page->pages
+ slab->slabs
|
- page = virt_to_head_page(E)
+ slab = virt_to_slab(E)
|
- virt_to_head_page(E)
+ virt_to_slab(E)
|
- page
+ slab
)
...>
}
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
These functions sit at the boundary to page allocator. Also use folio
internally to avoid extra compound_head() when dealing with page flags.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Update comments mentioning pages to mention slabs where appropriate.
Also some goto labels.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
The majority of conversion from struct page to struct slab in SLUB
internals can be delegated to a coccinelle semantic patch. This includes
renaming of variables with 'page' in name to 'slab', and similar.
Big thanks to Julia Lawall and Luis Chamberlain for help with
coccinelle.
// Options: --include-headers --no-includes --smpl-spacing include/linux/slub_def.h mm/slub.c
// Note: needs coccinelle 1.1.1 to avoid breaking whitespace, and ocaml for the
// embedded script
// build list of functions to exclude from applying the next rule
@initialize:ocaml@
@@
let ok_function p =
not (List.mem (List.hd p).current_element ["nearest_obj";"obj_to_index";"objs_per_slab_page";"__slab_lock";"__slab_unlock";"free_nonslab_page";"kmalloc_large_node"])
// convert the type from struct page to struct page in all functions except the
// list from previous rule
// this also affects struct kmem_cache_cpu, but that's ok
@@
position p : script:ocaml() { ok_function p };
@@
- struct page@p
+ struct slab
// in struct kmem_cache_cpu, change the name from page to slab
// the type was already converted by the previous rule
@@
@@
struct kmem_cache_cpu {
...
-struct slab *page;
+struct slab *slab;
...
}
// there are many places that use c->page which is now c->slab after the
// previous rule
@@
struct kmem_cache_cpu *c;
@@
-c->page
+c->slab
@@
@@
struct kmem_cache {
...
- unsigned int cpu_partial_pages;
+ unsigned int cpu_partial_slabs;
...
}
@@
struct kmem_cache *s;
@@
- s->cpu_partial_pages
+ s->cpu_partial_slabs
@@
@@
static void
- setup_page_debug(
+ setup_slab_debug(
...)
{...}
@@
@@
- setup_page_debug(
+ setup_slab_debug(
...);
// for all functions (with exceptions), change any "struct slab *page"
// parameter to "struct slab *slab" in the signature, and generally all
// occurences of "page" to "slab" in the body - with some special cases.
@@
identifier fn !~ "free_nonslab_page|obj_to_index|objs_per_slab_page|nearest_obj";
@@
fn(...,
- struct slab *page
+ struct slab *slab
,...)
{
<...
- page
+ slab
...>
}
// similar to previous but the param is called partial_page
@@
identifier fn;
@@
fn(...,
- struct slab *partial_page
+ struct slab *partial_slab
,...)
{
<...
- partial_page
+ partial_slab
...>
}
// similar to previous but for functions that take pointer to struct page ptr
@@
identifier fn;
@@
fn(...,
- struct slab **ret_page
+ struct slab **ret_slab
,...)
{
<...
- ret_page
+ ret_slab
...>
}
// functions converted by previous rules that were temporarily called using
// slab_page(E) so we want to remove the wrapper now that they accept struct
// slab ptr directly
@@
identifier fn =~ "slab_free|do_slab_free";
expression E;
@@
fn(...,
- slab_page(E)
+ E
,...)
// similar to previous but for another pattern
@@
identifier fn =~ "slab_pad_check|check_object";
@@
fn(...,
- folio_page(folio, 0)
+ slab
,...)
// functions that were returning struct page ptr and now will return struct
// slab ptr, including slab_page() wrapper removal
@@
identifier fn =~ "allocate_slab|new_slab";
expression E;
@@
static
-struct slab *
+struct slab *
fn(...)
{
<...
- slab_page(E)
+ E
...>
}
// rename any former struct page * declarations
@@
@@
struct slab *
(
- page
+ slab
|
- partial_page
+ partial_slab
|
- oldpage
+ oldslab
)
;
// this has to be separate from previous rule as page and page2 appear at the
// same line
@@
@@
struct slab *
-page2
+slab2
;
// similar but with initial assignment
@@
expression E;
@@
struct slab *
(
- page
+ slab
|
- flush_page
+ flush_slab
|
- discard_page
+ slab_to_discard
|
- page_to_unfreeze
+ slab_to_unfreeze
)
= E;
// convert most of struct page to struct slab usage inside functions (with
// exceptions), including specific variable renames
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
expression E;
@@
fn(...)
{
<...
(
- int pages;
+ int slabs;
|
- int pages = E;
+ int slabs = E;
|
- page
+ slab
|
- flush_page
+ flush_slab
|
- partial_page
+ partial_slab
|
- oldpage->pages
+ oldslab->slabs
|
- oldpage
+ oldslab
|
- unsigned int nr_pages;
+ unsigned int nr_slabs;
|
- nr_pages
+ nr_slabs
|
- unsigned int partial_pages = E;
+ unsigned int partial_slabs = E;
|
- partial_pages
+ partial_slabs
)
...>
}
// this has to be split out from the previous rule so that lines containing
// multiple matching changes will be fully converted
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
@@
fn(...)
{
<...
(
- slab->pages
+ slab->slabs
|
- pages
+ slabs
|
- page2
+ slab2
|
- discard_page
+ slab_to_discard
|
- page_to_unfreeze
+ slab_to_unfreeze
)
...>
}
// after we simply changed all occurences of page to slab, some usages need
// adjustment for slab-specific functions, or use slab_page() wrapper
@@
identifier fn !~ "nearest_obj|obj_to_index|objs_per_slab_page|__slab_(un)*lock|__free_slab|free_nonslab_page|kmalloc_large_node";
@@
fn(...)
{
<...
(
- page_slab(slab)
+ slab
|
- kasan_poison_slab(slab)
+ kasan_poison_slab(slab_page(slab))
|
- page_address(slab)
+ slab_address(slab)
|
- page_size(slab)
+ slab_size(slab)
|
- PageSlab(slab)
+ folio_test_slab(slab_folio(slab))
|
- page_to_nid(slab)
+ slab_nid(slab)
|
- compound_order(slab)
+ slab_order(slab)
)
...>
}
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Preparatory for mass conversion. Use the new slab_test_pfmemalloc()
helper. As it doesn't do VM_BUG_ON(!PageSlab()) we no longer need the
pfmemalloc_match_unsafe() variant.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
__free_slab() is on the boundary of distinguishing struct slab and
struct page so start with struct slab but convert to folio for working
with flags and folio_page() to call functions that require struct page.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Preparatory, callers convert back to struct page for now.
Also move setting page flags to alloc_slab_page() where we still operate
on a struct page. This means the page->slab_cache pointer is now set
later than the PageSlab flag, which could theoretically confuse some pfn
walker assuming PageSlab means there would be a valid cache pointer. But
as the code had no barriers and used __set_bit() anyway, it could have
happened already, so there shouldn't be such a walker.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Improve the type safety and prepare for further conversion. For flags
access, convert to folio internally.
[ vbabka@suse.cz: access flags via folio_flags() ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
These functions operate on the PG_locked page flag, but make them accept
struct slab to encapsulate this implementation detail.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Convert kfree(), kmem_cache_free() and ___cache_free() to resolve object
addresses to struct slab, using folio as intermediate step where needed.
Keep passing the result as struct page for now in preparation for mass
conversion of internal functions.
[ vbabka@suse.cz: Use folio as intermediate step when checking for
large kmalloc pages, and when freeing them - rename
free_nonslab_page() to free_large_kmalloc() that takes struct folio ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
This gives us a little bit of extra typesafety as we know that nobody
called virt_to_page() instead of virt_to_head_page().
[ vbabka@suse.cz: Use folio as intermediate step when filtering out
large kmalloc pages ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Ensure that we're not seeing a tail page inside __check_heap_object() by
converting to a slab instead of a page. Take the opportunity to mark
the slab as const since we're not modifying it. Also move the
declaration of __check_heap_object() to mm/slab.h so it's not available
to the wider kernel.
[ vbabka@suse.cz: in check_heap_object() only convert to struct slab for
actual PageSlab pages; use folio as intermediate step instead of page ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
All three implementations of slab support kmem_obj_info() which reports
details of an object allocated from the slab allocator. By using the
slab type instead of the page type, we make it obvious that this can
only be called for slabs.
[ vbabka@suse.cz: also convert the related kmem_valid_obj() to folios ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
In SLUB, use folios, and struct slab to access slab_cache field.
In SLOB, use folios to properly resolve pointers beyond
PAGE_SIZE offset of the object.
[ vbabka@suse.cz: use folios, and only convert folio_test_slab() == true
folios to struct slab ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
This function is entirely self-contained, so can be converted from page
to slab.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Convert the parameter of these functions to struct slab instead of
struct page and drop _page from the names. For now their callers just
convert page to slab.
[ vbabka@suse.cz: replace existing functions instead of calling them ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Make struct slab independent of struct page. It still uses the
underlying memory in struct page for storing slab-specific data, but
slab and slub can now be weaned off using struct page directly. Some of
the wrapper functions (slab_address() and slab_order()) still need to
cast to struct folio, but this is a significant disentanglement.
[ vbabka@suse.cz: Rebase on folios, use folio instead of page where
possible.
Do not duplicate flags field in struct slab, instead make the related
accessors go through slab_folio(). For testing pfmemalloc use the
folio_*_active flag accessors directly so the PageSlabPfmemalloc
wrappers can be removed later.
Make folio_slab() expect only folio_test_slab() == true folios and
virt_to_slab() return NULL when folio_test_slab() == false.
Move struct slab to mm/slab.h.
Don't represent with struct slab pages that are not true slab pages,
but just a compound page obtained directly rom page allocator (with
large kmalloc() for SLUB and SLOB). ]
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
There are no callers outside of mm/slub.c anymore.
Move freelist_corrupted() that calls object_err() to avoid a need for
forward declaration.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
The function no longer does what its name and comment suggests, and just
sets two struct page fields, which can be done directly in its sole
caller.
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Convert both callers of truncate_cleanup_page() to use
truncate_cleanup_folio() instead.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reimplement try_to_release_page() as a wrapper around
filemap_release_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This fixes a bug for tail pages. They always have a NULL mapping, so
the check would fail and we would never mark the folio as dirty.
Ends up growing the kernel by 19 bytes although there will be fewer
calls to compound_head() dynamically.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Saves 61 bytes due to fewer calls to compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This saves 105 bytes of text.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Saves one call to compound_head() and reduces text size by 15 bytes.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This saves a few calls to compound_head(), including one in
filemap_update_page(). Shrinks the kernel by 78 bytes.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Commit bd8a1f3655 ("mm/filemap: support readpage splitting a page")
changed the read_iter path to drop the refcount while waiting for the
page lock. However, it missed the same pattern in read_mapping_page()
and friends. Use the same pattern in do_read_cache_folio() that is
used in filemap_update_page().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reimplement read_cache_page() as a wrapper around read_cache_folio().
Saves over 400 bytes of text from do_read_cache_folio() which more
than makes up for the extra 100 bytes of text added to the various
wrapper functions.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Instead of converting back-and-forth between the actual page and
the head page, just convert once at the end of the function where we
set the vmf->page. Saves 241 bytes of text, or 15% of the size of
filemap_fault().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Call page_cache_async_ra() directly instead of indirecting through
page_cache_async_readahead().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This saves 99 bytes of kernel text.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Using the folio here avoids checking whether it's a tail page.
This patch mostly just enables some of the following patches.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
The only caller was already passing a head page, so this simply avoids
a call to compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
This is all internal to filemap and saves 100 bytes of text.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
One of the callers already had a folio; the other two grow by a few
bytes, but filemap_read_page() shrinks by 50 bytes for a net reduction
of 27 bytes.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
None of the callers of find_get_pages_contig() want tail pages. They all
use order-0 pages today, but if they were converted, they'd want folios.
So just remove the call to find_subpage() instead of replacing it with
folio_page().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
The page cache only stores folios, never tail pages. Saves 29 bytes
due to removing calls to compound_head().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Convert callers to cope. Saves 580 bytes of kernel text; all five
callers are reduced in size.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reimplement __delete_from_page_cache() as a wrapper around
__filemap_remove_folio() and delete_from_page_cache() as a wrapper
around filemap_remove_folio(). Remove the EXPORT_SYMBOL as
delete_from_page_cache() was not used by any in-tree modules.
Convert page_cache_free_page() into filemap_free_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Pass the folio instead of a page. The page was already implicitly a
folio as it accessed page->mapping directly. Add the order of the folio
to the tracepoint, as this is important information. Also drop printing
the address of the struct page as the pfn provides better information
than the struct page address.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Replace unaccount_page_cache_page() with filemap_unaccount_folio().
The bug handling path could be a bit more robust (eg taking into account
the mapcounts of tail pages), but it's really never supposed to happen.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
It was already assuming a head page, so this is a straightforward
conversion. Convert the one caller to call page_folio(), even though
it must currently be passing in a head page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Convert all three callers of put_and_wait_on_page_locked() to
folio_put_wait_locked(). This shrinks the kernel overall by 19 bytes.
filemap_update_page() shrinks by 19 bytes while __migration_entry_wait()
is unchanged. folio_put_wait_locked() is 14 bytes smaller than
put_and_wait_on_page_locked(), but pmd_migration_entry_wait() grows by
14 bytes. It removes the assumption from pmd_migration_entry_wait()
that pages cannot be larger than a PMD (which is true today, but
may be interesting to explore in the future).
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Add some notes about how this function needs to be called.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Pages are individually marked as suffering from hardware poisoning.
Checking that the head page is not hardware poisoned doesn't make
sense; we might be after a subpage. We check each page individually
before we use it, so this was an optimisation gone wrong.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Hugh Dickins reported the following
My tmpfs swapping load (tweaked to use huge pages more heavily
than in real life) is far from being a realistic load: but it was
notably slowed down by your throttling mods in 5.16-rc, and this
patch makes it well again - thanks.
But: it very quickly hit NULL pointer until I changed that last
line to
if (first_pgdat)
consider_reclaim_throttle(first_pgdat, sc);
The likely issue is that huge pages are a major component of the test
workload. When this is the case, first_pgdat may never get set if
compaction is ready to continue due to this check
if (IS_ENABLED(CONFIG_COMPACTION) &&
sc->order > PAGE_ALLOC_COSTLY_ORDER &&
compaction_ready(zone, sc)) {
sc->compaction_ready = true;
continue;
}
If this was true for every zone in the zonelist, first_pgdat would never
get set resulting in a NULL pointer exception.
Link: https://lkml.kernel.org/r/20211209095453.GM3366@techsingularity.net
Fixes: 1b4e3f26f9 ("mm: vmscan: Reduce throttling due to a failure to make progress")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Galbraith, Alexey Avramov and Darrick Wong all reported similar
problems due to reclaim throttling for excessive lengths of time. In
Alexey's case, a memory hog that should go OOM quickly stalls for
several minutes before stalling. In Mike and Darrick's cases, a small
memcg environment stalled excessively even though the system had enough
memory overall.
Commit 69392a403f ("mm/vmscan: throttle reclaim when no progress is
being made") introduced the problem although commit a19594ca4a
("mm/vmscan: increase the timeout if page reclaim is not making
progress") made it worse. Systems at or near an OOM state that cannot
be recovered must reach OOM quickly and memcg should kill tasks if a
memcg is near OOM.
To address this, only stall for the first zone in the zonelist, reduce
the timeout to 1 tick for VMSCAN_THROTTLE_NOPROGRESS and only stall if
the scan control nr_reclaimed is 0, kswapd is still active and there
were excessive pages pending for writeback. If kswapd has stopped
reclaiming due to excessive failures, do not stall at all so that OOM
triggers relatively quickly. Similarly, if an LRU is simply congested,
only lightly throttle similar to NOPROGRESS.
Alexey's original case was the most straight forward
for i in {1..3}; do tail /dev/zero; done
On vanilla 5.16-rc1, this test stalled heavily, after the patch the test
completes in a few seconds similar to 5.15.
Alexey's second test case added watching a youtube video while tail runs
10 times. On 5.15, playback only jitters slightly, 5.16-rc1 stalls a
lot with lots of frames missing and numerous audio glitches. With this
patch applies, the video plays similarly to 5.15.
[lkp@intel.com: Fix W=1 build warning]
Link: https://lore.kernel.org/r/99e779783d6c7fce96448a3402061b9dc1b3b602.camel@gmx.de
Link: https://lore.kernel.org/r/20211124011954.7cab9bb4@mail.inbox.lv
Link: https://lore.kernel.org/r/20211022144651.19914-1-mgorman@techsingularity.net
Link: https://lore.kernel.org/r/20211202150614.22440-1-mgorman@techsingularity.net
Link: https://linux-regtracking.leemhuis.info/regzbot/regression/20211124011954.7cab9bb4@mail.inbox.lv/
Reported-and-tested-by: Alexey Avramov <hakavlad@inbox.lv>
Reported-and-tested-by: Mike Galbraith <efault@gmx.de>
Reported-and-tested-by: Darrick J. Wong <djwong@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Tracked-by: Thorsten Leemhuis <regressions@leemhuis.info>
Fixes: 69392a403f ("mm/vmscan: throttle reclaim when no progress is being made")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAMON debugfs interface increases the reference counts of 'struct pid's
for targets from the 'target_ids' file write callback
('dbgfs_target_ids_write()'), but decreases the counts only in DAMON
monitoring termination callback ('dbgfs_before_terminate()').
Therefore, when 'target_ids' file is repeatedly written without DAMON
monitoring start/termination, the reference count is not decreased and
therefore memory for the 'struct pid' cannot be freed. This commit
fixes this issue by decreasing the reference counts when 'target_ids' is
written.
Link: https://lkml.kernel.org/r/20211229124029.23348-1-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hulk Robot reported a panic in put_page_testzero() when testing
madvise() with MADV_SOFT_OFFLINE. The BUG() is triggered when retrying
get_any_page(). This is because we keep MF_COUNT_INCREASED flag in
second try but the refcnt is not increased.
page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0)
------------[ cut here ]------------
kernel BUG at include/linux/mm.h:737!
invalid opcode: 0000 [#1] PREEMPT SMP
CPU: 5 PID: 2135 Comm: sshd Tainted: G B 5.16.0-rc6-dirty #373
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: release_pages+0x53f/0x840
Call Trace:
free_pages_and_swap_cache+0x64/0x80
tlb_flush_mmu+0x6f/0x220
unmap_page_range+0xe6c/0x12c0
unmap_single_vma+0x90/0x170
unmap_vmas+0xc4/0x180
exit_mmap+0xde/0x3a0
mmput+0xa3/0x250
do_exit+0x564/0x1470
do_group_exit+0x3b/0x100
__do_sys_exit_group+0x13/0x20
__x64_sys_exit_group+0x16/0x20
do_syscall_64+0x34/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
Modules linked in:
---[ end trace e99579b570fe0649 ]---
RIP: 0010:release_pages+0x53f/0x840
Link: https://lkml.kernel.org/r/20211221074908.3910286-1-liushixin2@huawei.com
Fixes: b94e02822d ("mm,hwpoison: try to narrow window race for free pages")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAMON debugfs interface iterates current monitoring targets in
'dbgfs_target_ids_read()' while holding the corresponding
'kdamond_lock'. However, it also destructs the monitoring targets in
'dbgfs_before_terminate()' without holding the lock. This can result in
a use_after_free bug. This commit avoids the race by protecting the
destruction with the corresponding 'kdamond_lock'.
Link: https://lkml.kernel.org/r/20211221094447.2241-1-sj@kernel.org
Reported-by: Sangwoo Bae <sangwoob@amazon.com>
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org> [5.15.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a memory error hits a tail page of a free hugepage,
__page_handle_poison() is expected to be called to isolate the error in
4kB unit, but it's not called due to the outdated if-condition in
memory_failure_hugetlb(). This loses the chance to isolate the error in
the finer unit, so it's not optimal. Drop the condition.
This "(p != head && TestSetPageHWPoison(head)" condition is based on the
old semantics of PageHWPoison on hugepage (where PG_hwpoison flag was
set on the subpage), so it's not necessray any more. By getting to set
PG_hwpoison on head page for hugepages, concurrent error events on
different subpages in a single hugepage can be prevented by
TestSetPageHWPoison(head) at the beginning of memory_failure_hugetlb().
So dropping the condition should not reopen the race window originally
mentioned in commit b985194c8c ("hwpoison, hugetlb:
lock_page/unlock_page does not match for handling a free hugepage")
[naoya.horiguchi@linux.dev: fix "HardwareCorrupted" counter]
Link: https://lkml.kernel.org/r/20211220084851.GA1460264@u2004
Link: https://lkml.kernel.org/r/20211210110208.879740-1-naoya.horiguchi@linux.dev
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Fei Luo <luofei@unicloud.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: <stable@vger.kernel.org> [5.14+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull percpu fixes from Dennis Zhou:
"This contains a fix for SMP && !MMU archs for percpu which has been
tested by arm and sh. It seems in the past they have gotten away with
it due to mapping of vm functions to km functions, but this fell apart
a few releases ago and was just reported recently.
The other is just a minor dependency clean up.
I think queued up right now by Andrew is a fix in percpu that papers
of what seems to be a bug in hotplug for a special situation with
memoryless nodes. Michal Hocko is digging into it further"
* 'for-5.16-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
percpu_ref: Replace kernel.h with the necessary inclusions
percpu: km: ensure it is used with NOMMU (either UP or SMP)
Initialize min_ratio if it is set during bdi unregistration. This can
prevent problems that may occur a when bdi is removed without resetting
min_ratio.
For example.
1) insert external sdcard
2) set external sdcard's min_ratio 70
3) remove external sdcard without setting min_ratio 0
4) insert external sdcard
5) set external sdcard's min_ratio 70 << error occur(can't set)
Because when an sdcard is removed, the present bdi_min_ratio value will
remain. Currently, the only way to reset bdi_min_ratio is to reboot.
[akpm@linux-foundation.org: tweak comment and coding style]
Link: https://lkml.kernel.org/r/20211021161942.5983-1-mj0123.lee@samsung.com
Signed-off-by: Manjong Lee <mj0123.lee@samsung.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Changheun Lee <nanich.lee@samsung.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <seunghwan.hyun@samsung.com>
Cc: <sookwan7.kim@samsung.com>
Cc: <yt0928.kim@samsung.com>
Cc: <junho89.kim@samsung.com>
Cc: <jisoo2146.oh@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Preallocation of gigantic pages can't work bacause of commit
b5389086ad ("hugetlbfs: extend the definition of hugepages parameter
to support node allocation"). When nid is NUMA_NO_NODE(-1),
alloc_bootmem_huge_page will always return without doing allocation.
Fix this by adding more check.
Link: https://lkml.kernel.org/r/20211129133803.15653-1-yaozhenguo1@gmail.com
Fixes: b5389086ad ("hugetlbfs: extend the definition of hugepages parameter to support node allocation")
Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All the calls to mod_objcg_mlstate(), get_obj_stock() and
put_obj_stock() are done by functions defined within the same "#ifdef
CONFIG_MEMCG_KMEM" compilation block. When CONFIG_MEMCG_KMEM isn't
defined, the following compilation warnings will be issued [1] and [2].
mm/memcontrol.c:785:20: warning: unused function 'mod_objcg_mlstate'
mm/memcontrol.c:2113:33: warning: unused function 'get_obj_stock'
Fix these warning by moving those functions to under the same
CONFIG_MEMCG_KMEM compilation block. There is no functional change.
[1] https://lore.kernel.org/lkml/202111272014.WOYNLUV6-lkp@intel.com/
[2] https://lore.kernel.org/lkml/202111280551.LXsWYt1T-lkp@intel.com/
Link: https://lkml.kernel.org/r/20211129161140.306488-1-longman@redhat.com
Fixes: 559271146e ("mm/memcg: optimize user context object stock access")
Fixes: 68ac5b3c8d ("mm/memcg: cache vmstat data in percpu memcg_stock_pcp")
Signed-off-by: Waiman Long <longman@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On big-endian s390, the alloc/free_traces attributes produce endless
output, because of always 0 idx in slab_debugfs_show().
idx is de-referenced from *v, which points to a loff_t value, with
unsigned int idx = *(unsigned int *)v;
This will only give the upper 32 bits on big-endian, which remain 0.
Instead of only fixing this de-reference, during discussion it seemed
more appropriate to change the seq_ops so that they use an explicit
iterator in private loc_track struct.
This patch adds idx to loc_track, which will also fix the endianness
bug.
Link: https://lore.kernel.org/r/20211117193932.4049412-1-gerald.schaefer@linux.ibm.com
Link: https://lkml.kernel.org/r/20211126171848.17534-1-gerald.schaefer@linux.ibm.com
Fixes: 64dd68497b ("mm: slub: move sysfs slab alloc/free interfaces to debugfs")
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Reported-by: Steffen Maier <maier@linux.ibm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A couple of test functions in DAMON virtual address space monitoring
primitives implementation has unnecessary damon_ctx variables. This
commit removes those.
Link: https://lkml.kernel.org/r/20211201150440.1088-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On some configuration[1], 'damon_test_split_evenly()' kunit test
function has >1024 bytes frame size, so below build warning is
triggered:
CC mm/damon/vaddr.o
In file included from mm/damon/vaddr.c:672:
mm/damon/vaddr-test.h: In function 'damon_test_split_evenly':
mm/damon/vaddr-test.h:309:1: warning: the frame size of 1064 bytes is larger than 1024 bytes [-Wframe-larger-than=]
309 | }
| ^
This commit fixes the warning by separating the common logic in the
function.
[1] https://lore.kernel.org/linux-mm/202111182146.OV3C4uGr-lkp@intel.com/
Link: https://lkml.kernel.org/r/20211201150440.1088-6-sj@kernel.org
Fixes: 17ccae8bb5 ("mm/damon: add kunit tests")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The DAMON virtual address space monitoring primitive prints a warning
message for wrong DAMOS action. However, it is not essential as the
code returns appropriate failure in the case. This commit removes the
message to make the log clean.
Link: https://lkml.kernel.org/r/20211201150440.1088-5-sj@kernel.org
Fixes: 6dea8add4d ("mm/damon/vaddr: support DAMON-based Operation Schemes")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAMON core prints error messages when damon_target object creation is
failed or wrong monitoring attributes are given. Because appropriate
error code is returned for each case, the messages are not essential.
Also, because the code path can be triggered with user-specified input,
this could result in kernel log mistakenly being messy. To avoid the
case, this commit removes the messages.
Link: https://lkml.kernel.org/r/20211201150440.1088-4-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Fixes: b9a6ac4e4e ("mm/damon: adaptively adjust regions")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When wrong scheme action is requested via the debugfs interface, DAMON
prints an error message. Because the function returns error code, this
is not really needed. Because the code path is triggered by the user
specified input, this can result in kernel log mistakenly being messy.
To avoid the case, this commit removes the message.
Link: https://lkml.kernel.org/r/20211201150440.1088-3-sj@kernel.org
Fixes: af122dd8f3 ("mm/damon/dbgfs: support DAMON-based Operation Schemes")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/damon: Trivial fixups and improvements".
This patchset contains trivial fixups and improvements for DAMON and its
kunit/kselftest tests.
This patch (of 11):
DAMON is using hrtimer if requested sleep time is <=100ms, while the
suggested threshold[1] is <=20ms. This commit applies the threshold.
[1] Documentation/timers/timers-howto.rst
Link: https://lkml.kernel.org/r/20211201150440.1088-2-sj@kernel.org
Fixes: ee801b7dd7 ("mm/damon/schemes: activate schemes based on a watermarks mechanism")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because DAMON sleeps in uninterruptible mode, /proc/loadavg reports fake
load while DAMON is turned on, though it is doing nothing. This can
confuse users[1]. To avoid the case, this commit makes DAMON sleeps in
idle mode.
[1] https://lore.kernel.org/all/11868371.O9o76ZdvQC@natalenko.name/
Link: https://lkml.kernel.org/r/20211126145015.15862-3-sj@kernel.org
Fixes: 2224d84854 ("mm: introduce Data Access MONitor (DAMON)")
Reported-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: SeongJae Park <sj@kernel.org>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pages are individually marked as suffering from hardware poisoning.
Checking that the head page is not hardware poisoned doesn't make
sense; we might be after a subpage. We check each page individually
before we use it, so this was an optimisation gone wrong. It will
cause us to fall back to the slow path when there was no need to do
that
Link: https://lkml.kernel.org/r/20211120174429.2596303-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some memory management calls imply memory barriers that are required to
avoid false positives. For example, without the correct instrumentation,
we could observe data races of the following variant:
T0 | T1
------------------------+------------------------
|
*a = 42; ---+ |
kfree(a); | |
| | b = kmalloc(..); // b == a
<reordered> <-+ | *b = 42; // not a data race!
|
Therefore, instrument memory barriers in all allocator code currently
not being instrumented in a default build.
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Daniel Borkmann says:
====================
bpf 2021-12-08
We've added 12 non-merge commits during the last 22 day(s) which contain
a total of 29 files changed, 659 insertions(+), 80 deletions(-).
The main changes are:
1) Fix an off-by-two error in packet range markings and also add a batch of
new tests for coverage of these corner cases, from Maxim Mikityanskiy.
2) Fix a compilation issue on MIPS JIT for R10000 CPUs, from Johan Almbladh.
3) Fix two functional regressions and a build warning related to BTF kfunc
for modules, from Kumar Kartikeya Dwivedi.
4) Fix outdated code and docs regarding BPF's migrate_disable() use on non-
PREEMPT_RT kernels, from Sebastian Andrzej Siewior.
5) Add missing includes in order to be able to detangle cgroup vs bpf header
dependencies, from Jakub Kicinski.
6) Fix regression in BPF sockmap tests caused by missing detachment of progs
from sockets when they are removed from the map, from John Fastabend.
7) Fix a missing "no previous prototype" warning in x86 JIT caused by BPF
dispatcher, from Björn Töpel.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf: Add selftests to cover packet access corner cases
bpf: Fix the off-by-two error in range markings
treewide: Add missing includes masked by cgroup -> bpf dependency
tools/resolve_btfids: Skip unresolved symbol warning for empty BTF sets
bpf: Fix bpf_check_mod_kfunc_call for built-in modules
bpf: Make CONFIG_DEBUG_INFO_BTF depend upon CONFIG_BPF_SYSCALL
mips, bpf: Fix reference to non-existing Kconfig symbol
bpf: Make sure bpf_disable_instrumentation() is safe vs preemption.
Documentation/locking/locktypes: Update migrate_disable() bits.
bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap
bpf, sockmap: Attach map progs to psock early for feature probes
bpf, x86: Fix "no previous prototype" warning
====================
Link: https://lore.kernel.org/r/20211208155125.11826-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, NOMMU pull km allocator via !SMP dependency because most of
them are UP, yet for SMP+NOMMU vm allocator gets pulled which:
* may lead to broken build [1]
* ...or not working runtime due to [2]
It looks like SMP+NOMMU case was overlooked in bbddff0545 ("percpu:
use percpu allocator on UP too") so restore that.
[1]
For ARM SMP+NOMMU (R-class cores)
arm-none-linux-gnueabihf-ld: mm/percpu.o: in function `pcpu_post_unmap_tlb_flush':
mm/percpu-vm.c:188: undefined reference to `flush_tlb_kernel_range'
[2]
static inline
int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
pgprot_t prot, struct page **pages, unsigned int page_shift)
{
return -EINVAL;
}
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Rob Landley <rob@landley.net>
Tested-by: Rich Felker <dalias@libc.org>
[Dennis: use depends instead of default for condition]
Signed-off-by: Dennis Zhou <dennis@kernel.org>
No driver is left using the external pgmap refcount, so remove the
code to support it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20211028151017.50234-1-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
No functional changes in this patch, just in preparation for efficiently
calling this light function from the block O_DIRECT handling.
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
cgroup.h (therefore swap.h, therefore half of the universe)
includes bpf.h which in turn includes module.h and slab.h.
Since we're about to get rid of that dependency we need
to clean things up.
v2: drop the cpu.h include from cacheinfo.h, it's not necessary
and it makes riscv sensitive to ordering of include files.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Krzysztof Wilczyński <kw@linux.com>
Acked-by: Peter Chen <peter.chen@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/all/20211120035253.72074-1-kuba@kernel.org/ # v1
Link: https://lore.kernel.org/all/20211120165528.197359-1-kuba@kernel.org/ # cacheinfo discussion
Link: https://lore.kernel.org/bpf/20211202203400.1208663-1-kuba@kernel.org
- Fix compilation warnings on csky and sparc
- Rename multipage folios to large folios
- Rename AS_THP_SUPPORT and FS_THP_SUPPORT
- Add functions to zero portions of a folio
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Merge tag 'folio-5.16b' of git://git.infradead.org/users/willy/pagecache
Pull folio fixes from Matthew Wilcox:
"In the course of preparing the folio changes for iomap for next merge
window, we discovered some problems that would be nice to address now:
- Renaming multi-page folios to large folios.
mapping_multi_page_folio_support() is just a little too long, so we
settled on mapping_large_folio_support(). That meant renaming, eg
folio_test_multi() to folio_test_large().
Rename AS_THP_SUPPORT to match
- I hadn't included folio wrappers for zero_user_segments(), etc.
Also, multi-page^W^W large folio support is now independent of
CONFIG_TRANSPARENT_HUGEPAGE, so machines with HIGHMEM always need
to fall back to the out-of-line zero_user_segments().
Remove FS_THP_SUPPORT to match
- The build bots finally got round to telling me that I missed a
couple of architectures when adding flush_dcache_folio(). Christoph
suggested that we just add linux/cacheflush.h and not rely on
asm-generic/cacheflush.h"
* tag 'folio-5.16b' of git://git.infradead.org/users/willy/pagecache:
mm: Add functions to zero portions of a folio
fs: Rename AS_THP_SUPPORT and mapping_thp_support
fs: Remove FS_THP_SUPPORT
mm: Remove folio_test_single
mm: Rename folio_test_multi to folio_test_large
Add linux/cacheflush.h
We must flush the TLB before releasing i_mmap_rwsem to avoid the
potential reuse of an unshared PMDs page. This is not true in the case
of move_hugetlb_page_tables(). The last reference on the page table can
therefore be dropped before the TLB flush took place.
Prevent it by reordering the operations and flushing the TLB before
releasing i_mmap_rwsem.
Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mina Almasry <almasrymina@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When __unmap_hugepage_range() calls to huge_pmd_unshare() succeed, a TLB
flush is missing. This TLB flush must be performed before releasing the
i_mmap_rwsem, in order to prevent an unshared PMDs page from being
released and reused before the TLB flush took place.
Arguably, a comprehensive solution would use mmu_gather interface to
batch the TLB flushes and the PMDs page release, however it is not an
easy solution: (1) try_to_unmap_one() and try_to_migrate_one() also call
huge_pmd_unshare() and they cannot use the mmu_gather interface; and (2)
deferring the release of the page reference for the PMDs page until
after i_mmap_rwsem is dropeed can confuse huge_pmd_unshare() into
thinking PMDs are shared when they are not.
Fix __unmap_hugepage_range() by adding the missing TLB flush, and
forcing a flush when unshare is successful.
Fixes: 24669e5847 ("hugetlb: use mmu_gather instead of a temporary linked list for accumulating pages)" # 3.6
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kmap_local conversion broke the ARM architecture, because the new
code assumes that all PTEs used for creating kmaps form a linear array
in memory, and uses array indexing to look up the kmap PTE belonging to
a certain kmap index.
On ARM, this cannot work, not only because the PTE pages may be
non-adjacent in memory, but also because ARM/!LPAE interleaves hardware
entries and extended entries (carrying software-only bits) in a way that
is not compatible with array indexing.
Fortunately, this only seems to affect configurations with more than 8
CPUs, due to the way the per-CPU kmap slots are organized in memory.
Work around this by permitting an architecture to set a Kconfig symbol
that signifies that the kmap PTEs do not form a lineary array in memory,
and so the only way to locate the appropriate one is to walk the page
tables.
Link: https://lore.kernel.org/linux-arm-kernel/20211026131249.3731275-1-ardb@kernel.org/
Link: https://lkml.kernel.org/r/20211116094737.7391-1-ardb@kernel.org
Fixes: 2a15ba82fa ("ARM: highmem: Switch to generic kmap atomic")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reported-by: Quanyang Wang <quanyang.wang@windriver.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAMON debugfs is supposed to protect dbgfs_ctxs, dbgfs_nr_ctxs, and
dbgfs_dirs using damon_dbgfs_lock. However, some of the code is
accessing the variables without the protection. This fixes it by
protecting all such accesses.
Link: https://lkml.kernel.org/r/20211110145758.16558-3-sj@kernel.org
Fixes: 75c1c2b53c ("mm/damon/dbgfs: support multiple contexts")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "DAMON fixes".
This patch (of 2):
DAMON users can trigger below warning in '__alloc_pages()' by invoking
write() to some DAMON debugfs files with arbitrarily high count
argument, because DAMON debugfs interface allocates some buffers based
on the user-specified 'count'.
if (unlikely(order >= MAX_ORDER)) {
WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
return NULL;
}
Because the DAMON debugfs interface code checks failure of the
'kmalloc()', this commit simply suppresses the warnings by adding
'__GFP_NOWARN' flag.
Link: https://lkml.kernel.org/r/20211110145758.16558-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211110145758.16558-2-sj@kernel.org
Fixes: 4bc05954d0 ("mm/damon: implement a debugfs-based user space interface")
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently in the is_continue case in hugetlb_mcopy_atomic_pte(), if we
bail out using "goto out_release_unlock;" in the cases where idx >=
size, or !huge_pte_none(), the code will detect that new_pagecache_page
== false, and so call restore_reserve_on_error(). In this case I see
restore_reserve_on_error() delete the reservation, and the following
call to remove_inode_hugepages() will increment h->resv_hugepages
causing a 100% reproducible leak.
We should treat the is_continue case similar to adding a page into the
pagecache and set new_pagecache_page to true, to indicate that there is
no reservation to restore on the error path, and we need not call
restore_reserve_on_error(). Rename new_pagecache_page to
page_in_pagecache to make that clear.
Link: https://lkml.kernel.org/r/20211117193825.378528-1-almasrymina@google.com
Fixes: c7b1850dfb ("hugetlb: don't pass page cache pages to restore_reserve_on_error")
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reported-by: James Houghton <jthoughton@google.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Wei Xu <weixugc@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When hugetlb_vm_op_open() is called during copy_vma(), we may take the
reference to resv_map->css. Later, when clearing the reservation
pointer of old_vma after transferring it to new_vma, we forget to drop
the reference to resv_map->css. This leads to a reference leak of css.
Fixes this by adding a check to drop reservation css reference in
clear_vma_resv_huge_pages()
Link: https://lkml.kernel.org/r/20211113154412.91134-1-minhquangbui99@gmail.com
Fixes: 550a7d60bd ("mm, hugepages: add mremap() support for hugepage backed vma")
Signed-off-by: Bui Quang Minh <minhquangbui99@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Mina Almasry <almasrymina@google.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When kmemleak is enabled for SLOB, system does not boot and does not
print anything to the console. At the very early stage in the boot
process we hit infinite recursion from kmemleak_init() and eventually
kernel crashes.
kmemleak_init() specifies SLAB_NOLEAKTRACE for KMEM_CACHE(), but
kmem_cache_create_usercopy() removes it because CACHE_CREATE_MASK is not
valid for SLOB.
Let's fix CACHE_CREATE_MASK and make kmemleak work with SLOB
Link: https://lkml.kernel.org/r/20211115020850.3154366-1-rkovhaev@gmail.com
Fixes: d8843922fb ("slab: Ignore internal flags in cache creation")
Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Glauber Costa <glommer@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After the memory is freed, it can be immediately allocated by other
CPUs, before the "free" trace report has been emitted. This causes
inaccurate traces.
For example, if the following sequence of events occurs:
CPU 0 CPU 1
(1) alloc xxxxxx
(2) free xxxxxx
(3) alloc xxxxxx
(4) free xxxxxx
Then they will be inaccurately reported via tracing, so that they appear
to have happened in this order:
CPU 0 CPU 1
(1) alloc xxxxxx
(2) alloc xxxxxx
(3) free xxxxxx
(4) free xxxxxx
This makes it look like CPU 1 somehow managed to allocate memory that
CPU 0 still had allocated for itself.
In order to avoid this, emit the "free xxxxxx" tracing report just
before the actual call to free the memory, instead of just after it.
Link: https://lkml.kernel.org/r/374eb75d-7404-8721-4e1e-65b0e5b17279@huawei.com
Signed-off-by: Yunfeng Ye <yeyunfeng@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While free_unref_page_list() puts pages onto the CPU local LRU list, it
does not remove them from the list they were passed in on. That makes
the list_head appear to be non-empty, and would lead to various
corruption problems if we didn't have an assertion that the list was
empty.
Reinitialise the list after calling free_unref_page_list() to avoid this
problem.
Link: https://lkml.kernel.org/r/YYp40A2lNrxaZji8@casper.infradead.org
Fixes: 988c69f1bc ("mm: optimise put_pages_list()")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Steve French <stfrench@microsoft.com>
Reported-by: Namjae Jeon <linkinjeon@kernel.org>
Tested-by: Steve French <stfrench@microsoft.com>
Tested-by: Namjae Jeon <linkinjeon@kernel.org>
Cc: Steve French <smfrench@gmail.com>
Cc: Hyeoncheol Lee <hyc.lee@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These functions are wrappers around zero_user_segments(), which means
that zero_user_segments() can now be called for compound pages even when
CONFIG_TRANSPARENT_HUGEPAGE is disabled.
Use 'xend' as the name of the parameter to indicate that this is an
excluded end, not the more usual included end. Excluding the end makes
more sense to the callers, but can cause confusion to readers who are
more used to seeing included ends.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Instead of setting a bit in the fs_flags to set a bit in the
address_space, set the bit in the address_space directly.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Add a call inside memory_failure() to call the arch specific code
to check if the address is an SGX EPC page and handle it.
Note the SGX EPC pages do not have a "struct page" entry, so the hook
goes in at the same point as the device mapping hook.
Pull the call to acquire the mutex earlier so the SGX errors are also
protected.
Make set_mce_nospec() skip SGX pages when trying to adjust
the 1:1 map.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/20211026220050.697075-6-tony.luck@intel.com
This reverts commit b9d02f1bdd.
The error handling of that patch was fundamentally broken, and it needs
to be entirely re-done.
For example, in shmem_write_begin() it would call shmem_getpage(), then
ignore the error return from that, and look at the page pointer contents
instead.
And in shmem_read_mapping_page_gfp(), the patch tested PageHWPoison() on
a page pointer that two lines earlier had potentially been set as an
error pointer.
These issues could be individually fixed, but when it has this many
issues, I'm just reverting it instead of waiting for fixes.
Link: https://lore.kernel.org/linux-mm/20211111084617.6746-1-ajaygargnsit@gmail.com/
Reported-by: Ajay Garg <ajaygargnsit@gmail.com>
Reported-by: Jens Axboe <axboe@kernel.dk>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'netfs-folio-20211111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull netfs, 9p, afs and ceph (partial) foliation from David Howells:
"This converts netfslib, 9p and afs to use folios. It also partially
converts ceph so that it uses folios on the boundaries with netfslib.
To help with this, a couple of folio helper functions are added in the
first two patches.
These patches don't touch fscache and cachefiles as I intend to remove
all the code that deals with pages directly from there. Only nfs and
cifs are using the old fscache I/O API now. The new API uses iov_iter
instead.
Thanks to Jeff Layton, Dominique Martinet and AuriStor for testing and
retesting the patches"
* tag 'netfs-folio-20211111' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Use folios in directory handling
netfs, 9p, afs, ceph: Use folios
folio: Add a function to get the host inode for a folio
folio: Add a function to change the private data attached to a folio
Merge more updates from Andrew Morton:
"The post-linux-next material.
7 patches.
Subsystems affected by this patch series (all mm): debug,
slab-generic, migration, memcg, and kasan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kasan: add kasan mode messages when kasan init
mm: unexport {,un}lock_page_memcg
mm: unexport folio_memcg_{,un}lock
mm/migrate.c: remove MIGRATE_PFN_LOCKED
mm: migrate: simplify the file-backed pages validation when migrating its mapping
mm: allow only SLUB on PREEMPT_RT
mm/page_owner.c: modify the type of argument "order" in some functions
and netfilter.
Current release - regressions:
- bpf: do not reject when the stack read size is different
from the tracked scalar size
- net: fix premature exit from NAPI state polling in napi_disable()
- riscv, bpf: fix RV32 broken build, and silence RV64 warning
Current release - new code bugs:
- net: fix possible NULL deref in sock_reserve_memory
- amt: fix error return code in amt_init(); fix stopping the workqueue
- ax88796c: use the correct ioctl callback
Previous releases - always broken:
- bpf: stop caching subprog index in the bpf_pseudo_func insn
- security: fixups for the security hooks in sctp
- nfc: add necessary privilege flags in netlink layer, limit operations
to admin only
- vsock: prevent unnecessary refcnt inc for non-blocking connect
- net/smc: fix sk_refcnt underflow on link down and fallback
- nfnetlink_queue: fix OOB when mac header was cleared
- can: j1939: ignore invalid messages per standard
- bpf, sockmap:
- fix race in ingress receive verdict with redirect to self
- fix incorrect sk_skb data_end access when src_reg = dst_reg
- strparser, and tls are reusing qdisc_skb_cb and colliding
- ethtool: fix ethtool msg len calculation for pause stats
- vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries
to access an unregistering real_dev
- udp6: make encap_rcv() bump the v6 not v4 stats
- drv: prestera: add explicit padding to fix m68k build
- drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge
- drv: mvpp2: fix wrong SerDes reconfiguration order
Misc & small latecomers:
- ipvs: auto-load ipvs on genl access
- mctp: sanity check the struct sockaddr_mctp padding fields
- libfs: support RENAME_EXCHANGE in simple_rename()
- avoid double accounting for pure zerocopy skbs
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf, can and netfilter.
Current release - regressions:
- bpf: do not reject when the stack read size is different from the
tracked scalar size
- net: fix premature exit from NAPI state polling in napi_disable()
- riscv, bpf: fix RV32 broken build, and silence RV64 warning
Current release - new code bugs:
- net: fix possible NULL deref in sock_reserve_memory
- amt: fix error return code in amt_init(); fix stopping the
workqueue
- ax88796c: use the correct ioctl callback
Previous releases - always broken:
- bpf: stop caching subprog index in the bpf_pseudo_func insn
- security: fixups for the security hooks in sctp
- nfc: add necessary privilege flags in netlink layer, limit
operations to admin only
- vsock: prevent unnecessary refcnt inc for non-blocking connect
- net/smc: fix sk_refcnt underflow on link down and fallback
- nfnetlink_queue: fix OOB when mac header was cleared
- can: j1939: ignore invalid messages per standard
- bpf, sockmap:
- fix race in ingress receive verdict with redirect to self
- fix incorrect sk_skb data_end access when src_reg = dst_reg
- strparser, and tls are reusing qdisc_skb_cb and colliding
- ethtool: fix ethtool msg len calculation for pause stats
- vlan: fix a UAF in vlan_dev_real_dev() when ref-holder tries to
access an unregistering real_dev
- udp6: make encap_rcv() bump the v6 not v4 stats
- drv: prestera: add explicit padding to fix m68k build
- drv: felix: fix broken VLAN-tagged PTP under VLAN-aware bridge
- drv: mvpp2: fix wrong SerDes reconfiguration order
Misc & small latecomers:
- ipvs: auto-load ipvs on genl access
- mctp: sanity check the struct sockaddr_mctp padding fields
- libfs: support RENAME_EXCHANGE in simple_rename()
- avoid double accounting for pure zerocopy skbs"
* tag 'net-5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (123 commits)
selftests/net: udpgso_bench_rx: fix port argument
net: wwan: iosm: fix compilation warning
cxgb4: fix eeprom len when diagnostics not implemented
net: fix premature exit from NAPI state polling in napi_disable()
net/smc: fix sk_refcnt underflow on linkdown and fallback
net/mlx5: Lag, fix a potential Oops with mlx5_lag_create_definer()
gve: fix unmatched u64_stats_update_end()
net: ethernet: lantiq_etop: Fix compilation error
selftests: forwarding: Fix packet matching in mirroring selftests
vsock: prevent unnecessary refcnt inc for nonblocking connect
net: marvell: mvpp2: Fix wrong SerDes reconfiguration order
net: ethernet: ti: cpsw_ale: Fix access to un-initialized memory
net: stmmac: allow a tc-taprio base-time of zero
selftests: net: test_vxlan_under_vrf: fix HV connectivity test
net: hns3: allow configure ETS bandwidth of all TCs
net: hns3: remove check VF uc mac exist when set by PF
net: hns3: fix some mac statistics is always 0 in device version V2
net: hns3: fix kernel crash when unload VF while it is being reset
net: hns3: sync rx ring head in echo common pull
net: hns3: fix pfc packet number incorrect after querying pfc parameters
...
There are multiple kasan modes. It makes sense that we add some
messages to know which kasan mode is active when booting up [1].
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212195 [1]
Link: https://lkml.kernel.org/r/20211020094850.4113-1-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Yee Lee <yee.lee@mediatek.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are only used in built-in core mm code.
Link: https://lkml.kernel.org/r/20210820095815.445392-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "unexport memcg locking helpers".
Neither the old page-based nor the new folio-based memcg locking helpers
are used in modular code at all, so drop the exports.
This patch (of 2):
folio_memcg_{,un}lock are only used in built-in core mm code.
Link: https://lkml.kernel.org/r/20210820095815.445392-1-hch@lst.de
Link: https://lkml.kernel.org/r/20210820095815.445392-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MIGRATE_PFN_LOCKED is used to indicate to migrate_vma_prepare() that a
source page was already locked during migrate_vma_collect(). If it
wasn't then the a second attempt is made to lock the page. However if
the first attempt failed it's unlikely a second attempt will succeed,
and the retry adds complexity. So clean this up by removing the retry
and MIGRATE_PFN_LOCKED flag.
Destination pages are also meant to have the MIGRATE_PFN_LOCKED flag
set, but nothing actually checks that.
Link: https://lkml.kernel.org/r/20211025041608.289017-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no need to validate the file-backed page's refcount before
trying to freeze the page's expected refcount, instead we can rely on
the folio_ref_freeze() to validate if the page has the expected refcount
before migrating its mapping.
Moreover we are always under the page lock when migrating the page
mapping, which means nowhere else can remove it from the page cache, so
we can remove the xas_load() validation under the i_pages lock.
Link: https://lkml.kernel.org/r/cover.1629447552.git.baolin.wang@linux.alibaba.com
Link: https://lkml.kernel.org/r/df4c129fd8e86a95dbc55f4663d77441cc0d3bd1.1629447552.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The type of "order" in struct page_owner is unsigned short.
However, it is unsigned int in the following 3 functions:
__reset_page_owner
__set_page_owner_handle
__set_page_owner_handle
The type of "order" in argument list is unsigned int, which is
inconsistent.
[akpm@linux-foundation.org: update include/linux/page_owner.h]
Link: https://lkml.kernel.org/r/20211020125945.47792-1-caoyixuan2019@email.szu.edu.cn
Signed-off-by: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'pidfd.v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull pidfd updates from Christian Brauner:
"Various places in the kernel have picked up pidfds.
The two most recent additions have probably been the ability to use
pidfds in bpf maps and the usage of pidfds in mm-based syscalls such
as process_mrelease() and process_madvise().
The same pattern to turn a pidfd into a struct task exists in two
places. One of those places used PIDTYPE_TGID while the other one used
PIDTYPE_PID even though it is clearly documented in all pidfd-helpers
that pidfds __currently__ only refer to thread-group leaders (subject
to change in the future if need be).
This isn't a bug per se but has the potential to be one if we allow
pidfds to refer to individual threads. If that happens we want to
audit all codepaths that make use of them to ensure they can deal with
pidfds refering to individual threads.
This adds a simple helper to turn a pidfd into a struct task making it
easy to grep for such places. Plus, it gets rid of code-duplication"
* tag 'pidfd.v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
mm: use pidfd_get_task()
pid: add pidfd_get_task() helper
- Fix double-evaluation of 'pte' macro argument when using 52-bit PAs
- Fix signedness of some MTE prctl PR_* constants
- Fix kmemleak memory usage by skipping early pgtable allocations
- Fix printing of CPU feature register strings
- Remove redundant -nostdlib linker flag for vDSO binaries
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Will Deacon:
- Fix double-evaluation of 'pte' macro argument when using 52-bit PAs
- Fix signedness of some MTE prctl PR_* constants
- Fix kmemleak memory usage by skipping early pgtable allocations
- Fix printing of CPU feature register strings
- Remove redundant -nostdlib linker flag for vDSO binaries
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: pgtable: make __pte_to_phys/__phys_to_pte_val inline functions
arm64: Track no early_pgtable_alloc() for kmemleak
arm64: mte: change PR_MTE_TCF_NONE back into an unsigned long
arm64: vdso: remove -nostdlib compiler flag
arm64: arm64_ftr_reg->name may not be a human-readable string
Merge more updates from Andrew Morton:
"87 patches.
Subsystems affected by this patch series: mm (pagecache and hugetlb),
procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
sysvfs, kcov, gdb, resource, selftests, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
selftests/kselftest/runner/run_one(): allow running non-executable files
virtio-mem: disallow mapping virtio-mem memory via /dev/mem
kernel/resource: disallow access to exclusive system RAM regions
kernel/resource: clean up and optimize iomem_is_exclusive()
scripts/gdb: handle split debug for vmlinux
kcov: replace local_irq_save() with a local_lock_t
kcov: avoid enable+disable interrupts if !in_task()
kcov: allocate per-CPU memory on the relevant node
Documentation/kcov: define `ip' in the example
Documentation/kcov: include types.h in the example
sysv: use BUILD_BUG_ON instead of runtime check
kernel/fork.c: unshare(): use swap() to make code cleaner
seq_file: fix passing wrong private data
seq_file: move seq_escape() to a header
signal: remove duplicate include in signal.h
crash_dump: remove duplicate include in crash_dump.h
crash_dump: fix boolreturn.cocci warning
hfs/hfsplus: use WARN_ON for sanity check
...
virtio-mem dynamically exposes memory inside a device memory region as
system RAM to Linux, coordinating with the hypervisor which parts are
actually "plugged" and consequently usable/accessible.
On the one hand, the virtio-mem driver adds/removes whole memory blocks,
creating/removing busy IORESOURCE_SYSTEM_RAM resources, on the other
hand, it logically (un)plugs memory inside added memory blocks,
dynamically either exposing them to the buddy or hiding them from the
buddy and marking them PG_offline.
In contrast to physical devices, like a DIMM, the virtio-mem driver is
required to actually make use of any of the device-provided memory,
because it performs the handshake with the hypervisor. virtio-mem
memory cannot simply be access via /dev/mem without a driver.
There is no safe way to:
a) Access plugged memory blocks via /dev/mem, as they might contain
unplugged holes or might get silently unplugged by the virtio-mem
driver and consequently turned inaccessible.
b) Access unplugged memory blocks via /dev/mem because the virtio-mem
driver is required to make them actually accessible first.
The virtio-spec states that unplugged memory blocks MUST NOT be written,
and only selected unplugged memory blocks MAY be read. We want to make
sure, this is the case in sane environments -- where the virtio-mem driver
was loaded.
We want to make sure that in a sane environment, nobody "accidentially"
accesses unplugged memory inside the device managed region. For example,
a user might spot a memory region in /proc/iomem and try accessing it via
/dev/mem via gdb or dumping it via something else. By the time the mmap()
happens, the memory might already have been removed by the virtio-mem
driver silently: the mmap() would succeeed and user space might
accidentially access unplugged memory.
So once the driver was loaded and detected the device along the
device-managed region, we just want to disallow any access via /dev/mem to
it.
In an ideal world, we would mark the whole region as busy ("owned by a
driver") and exclude it; however, that would be wrong, as we don't really
have actual system RAM at these ranges added to Linux ("busy system RAM").
Instead, we want to mark such ranges as "not actual busy system RAM but
still soft-reserved and prepared by a driver for future use."
Let's teach iomem_is_exclusive() to reject access to any range with
"IORESOURCE_SYSTEM_RAM | IORESOURCE_EXCLUSIVE", even if not busy and even
if "iomem=relaxed" is set. Introduce EXCLUSIVE_SYSTEM_RAM to make it
easier for applicable drivers to depend on this setting in their Kconfig.
For now, there are no applicable ranges and we'll modify virtio-mem next
to properly set IORESOURCE_EXCLUSIVE on the parent resource container it
creates to contain all actual busy system RAM added via
add_memory_driver_managed().
Link: https://lkml.kernel.org/r/20210920142856.17758-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To print stack entries into a buffer, users of stackdepot, first get a
list of stack entries using stack_depot_fetch and then print this list
into a buffer using stack_trace_snprint. Provide a helper in stackdepot
for this purpose. Also change above mentioned users to use this helper.
[imran.f.khan@oracle.com: fix build error]
Link: https://lkml.kernel.org/r/20210915175321.3472770-4-imran.f.khan@oracle.com
[imran.f.khan@oracle.com: export stack_depot_snprint() to modules]
Link: https://lkml.kernel.org/r/20210916133535.3592491-4-imran.f.khan@oracle.com
Link: https://lkml.kernel.org/r/20210915014806.3206938-4-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Jani Nikula <jani.nikula@intel.com> [i915]
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To print a stack entries, users of stackdepot, first use stack_depot_fetch
to get a list of stack entries and then use stack_trace_print to print
this list. Provide a helper in stackdepot to print stack entries based on
stackdepot handle. Also change above mentioned users to use this helper.
Link: https://lkml.kernel.org/r/20210915014806.3206938-3-imran.f.khan@oracle.com
Signed-off-by: Imran Khan <imran.f.khan@oracle.com>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 21a3c273f8 ("mm, hugetlb: add thread name and pid to
SHM_HUGETLB mlock rlimit warning") marked this as deprecated in 2012,
but it is not deleted yet.
Mike says he still sees that message in log files on occasion, so maybe we
should preserve this warning.
Also remove hugetlbfs related user_shm_unlock in ipc/shm.c and remove the
user_shm_unlock after out.
Link: https://lkml.kernel.org/r/20211103105857.25041-1-zhangyiru3@huawei.com
Signed-off-by: zhangyiru <zhangyiru3@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liu Zixian <liuzixian4@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: wuxu.wu <wuxu.wu@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Historically (pre-2.5), the inode shrinker used to reclaim only empty
inodes and skip over those that still contained page cache. This caused
problems on highmem hosts: struct inode could put fill lowmem zones
before the cache was getting reclaimed in the highmem zones.
To address this, the inode shrinker started to strip page cache to
facilitate reclaiming lowmem. However, this comes with its own set of
problems: the shrinkers may drop actively used page cache just because
the inodes are not currently open or dirty - think working with a large
git tree. It further doesn't respect cgroup memory protection settings
and can cause priority inversions between containers.
Nowadays, the page cache also holds non-resident info for evicted cache
pages in order to detect refaults. We've come to rely heavily on this
data inside reclaim for protecting the cache workingset and driving swap
behavior. We also use it to quantify and report workload health through
psi. The latter in turn is used for fleet health monitoring, as well as
driving automated memory sizing of workloads and containers, proactive
reclaim and memory offloading schemes.
The consequences of dropping page cache prematurely is that we're seeing
subtle and not-so-subtle failures in all of the above-mentioned
scenarios, with the workload generally entering unexpected thrashing
states while losing the ability to reliably detect it.
To fix this on non-highmem systems at least, going back to rotating
inodes on the LRU isn't feasible. We've tried (commit a76cf1a474
("mm: don't reclaim inodes with many attached pages")) and failed
(commit 69056ee6a8 ("Revert "mm: don't reclaim inodes with many
attached pages"")).
The issue is mostly that shrinker pools attract pressure based on their
size, and when objects get skipped the shrinkers remember this as
deferred reclaim work. This accumulates excessive pressure on the
remaining inodes, and we can quickly eat into heavily used ones, or
dirty ones that require IO to reclaim, when there potentially is plenty
of cold, clean cache around still.
Instead, this patch keeps populated inodes off the inode LRU in the
first place - just like an open file or dirty state would. An otherwise
clean and unused inode then gets queued when the last cache entry
disappears. This solves the problem without reintroducing the reclaim
issues, and generally is a bit more scalable than having to wade through
potentially hundreds of thousands of busy inodes.
Locking is a bit tricky because the locks protecting the inode state
(i_lock) and the inode LRU (lru_list.lock) don't nest inside the
irq-safe page cache lock (i_pages.xa_lock). Page cache deletions are
serialized through i_lock, taken before the i_pages lock, to make sure
depopulated inodes are queued reliably. Additions may race with
deletions, but we'll check again in the shrinker. If additions race
with the shrinker itself, we're protected by the i_lock: if find_inode()
or iput() win, the shrinker will bail on the elevated i_count or
I_REFERENCED; if the shrinker wins and goes ahead with the inode, it
will set I_FREEING and inhibit further igets(), which will cause the
other side to create a new instance of the inode instead.
Link: https://lkml.kernel.org/r/20210614211904.14420-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After switched page size from 64KB to 4KB on several arm64 servers here,
kmemleak starts to run out of early memory pool due to a huge number of
those early_pgtable_alloc() calls:
kmemleak_alloc_phys()
memblock_alloc_range_nid()
memblock_phys_alloc_range()
early_pgtable_alloc()
init_pmd()
alloc_init_pud()
__create_pgd_mapping()
__map_memblock()
paging_init()
setup_arch()
start_kernel()
Increased the default value of DEBUG_KMEMLEAK_MEM_POOL_SIZE by 4 times
won't be enough for a server with 200GB+ memory. There isn't much
interesting to check memory leaks for those early page tables and those
early memory mappings should not reference to other memory. Hence, no
kmemleak false positives, and we can safely skip tracking those early
allocations from kmemleak like we did in the commit fed84c7852
("mm/memblock.c: skip kmemleak for kasan_init()") without needing to
introduce complications to automatically scale the value depends on the
runtime memory size etc. After the patch, the default value of
DEBUG_KMEMLEAK_MEM_POOL_SIZE becomes sufficient again.
Signed-off-by: Qian Cai <quic_qiancai@quicinc.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/20211105150509.7826-1-quic_qiancai@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>
Merge misc updates from Andrew Morton:
"257 patches.
Subsystems affected by this patch series: scripts, ocfs2, vfs, and
mm (slab-generic, slab, slub, kconfig, dax, kasan, debug, pagecache,
gup, swap, memcg, pagemap, mprotect, mremap, iomap, tracing, vmalloc,
pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, tools,
memblock, oom-kill, hugetlbfs, migration, thp, readahead, nommu, ksm,
vmstat, madvise, memory-hotplug, rmap, zsmalloc, highmem, zram,
cleanups, kfence, and damon)"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (257 commits)
mm/damon: remove return value from before_terminate callback
mm/damon: fix a few spelling mistakes in comments and a pr_debug message
mm/damon: simplify stop mechanism
Docs/admin-guide/mm/pagemap: wordsmith page flags descriptions
Docs/admin-guide/mm/damon/start: simplify the content
Docs/admin-guide/mm/damon/start: fix a wrong link
Docs/admin-guide/mm/damon/start: fix wrong example commands
mm/damon/dbgfs: add adaptive_targets list check before enable monitor_on
mm/damon: remove unnecessary variable initialization
Documentation/admin-guide/mm/damon: add a document for DAMON_RECLAIM
mm/damon: introduce DAMON-based Reclamation (DAMON_RECLAIM)
selftests/damon: support watermarks
mm/damon/dbgfs: support watermarks
mm/damon/schemes: activate schemes based on a watermarks mechanism
tools/selftests/damon: update for regions prioritization of schemes
mm/damon/dbgfs: support prioritization weights
mm/damon/vaddr,paddr: support pageout prioritization
mm/damon/schemes: prioritize regions within the quotas
mm/damon/selftests: support schemes quotas
mm/damon/dbgfs: support quotas of schemes
...
Since the return value of 'before_terminate' callback is never used, we
make it have no return value.
Link: https://lkml.kernel.org/r/20211029005023.8895-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are a few spelling mistakes in the code. Fix these.
Link: https://lkml.kernel.org/r/20211028184157.614544-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A kernel thread can exit gracefully with kthread_stop(). So we don't
need a new flag 'kdamond_stop'. And to make sure the task struct is not
freed when accessing it, get reference to it before termination.
Link: https://lkml.kernel.org/r/20211027130517.4404-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When the ctx->adaptive_targets list is empty, I did some test on
monitor_on interface like this.
# cat /sys/kernel/debug/damon/target_ids
#
# echo on > /sys/kernel/debug/damon/monitor_on
# damon: kdamond (5390) starts
Though the ctx->adaptive_targets list is empty, but the kthread_run
still be called, and the kdamond.x thread still be created, this is
meaningless.
So there adds a judgment in 'dbgfs_monitor_on_write', if the
ctx->adaptive_targets list is empty, return -EINVAL.
Link: https://lkml.kernel.org/r/0a60a6e8ec9d71989e0848a4dc3311996ca3b5d4.1634720326.git.xhao@linux.alibaba.com
Signed-off-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This implements a new kernel subsystem that finds cold memory regions
using DAMON and reclaims those immediately. It is intended to be used
as proactive lightweigh reclamation logic for light memory pressure.
For heavy memory pressure, it could be inactivated and fall back to the
traditional page-scanning based reclamation.
It's implemented on top of DAMON framework to use the DAMON-based
Operation Schemes (DAMOS) feature. It utilizes all the DAMOS features
including speed limit, prioritization, and watermarks.
It could be enabled and tuned in boot time via the kernel boot
parameter, and in run time via its module parameters
('/sys/module/damon_reclaim/parameters/') interface.
[yangyingliang@huawei.com: fix error return code in damon_reclaim_turn()]
Link: https://lkml.kernel.org/r/20211025124500.2758060-1-yangyingliang@huawei.com
Link: https://lkml.kernel.org/r/20211019150731.16699-15-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This updates DAMON debugfs interface to support the watermarks based
schemes activation. For this, now 'schemes' file receives five more
values.
Link: https://lkml.kernel.org/r/20211019150731.16699-13-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAMON-based operation schemes need to be manually turned on and off. In
some use cases, however, the condition for turning a scheme on and off
would depend on the system's situation. For example, schemes for
proactive pages reclamation would need to be turned on when some memory
pressure is detected, and turned off when the system has enough free
memory.
For easier control of schemes activation based on the system situation,
this introduces a watermarks-based mechanism. The client can describe
the watermark metric (e.g., amount of free memory in the system),
watermark check interval, and three watermarks, namely high, mid, and
low. If the scheme is deactivated, it only gets the metric and compare
that to the three watermarks for every check interval. If the metric is
higher than the high watermark, the scheme is deactivated. If the
metric is between the mid watermark and the low watermark, the scheme is
activated. If the metric is lower than the low watermark, the scheme is
deactivated again. This is to allow users fall back to traditional
page-granularity mechanisms.
Link: https://lkml.kernel.org/r/20211019150731.16699-12-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows DAMON debugfs interface users set the prioritization weights
by putting three more numbers to the 'schemes' file.
Link: https://lkml.kernel.org/r/20211019150731.16699-10-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes the default monitoring primitives for virtual address spaces
and the physical address sapce to support memory regions prioritization
for 'PAGEOUT' DAMOS action. It calculates hotness of each region as
weighted sum of 'nr_accesses' and 'age' of the region and get the
priority score as reverse of the hotness, so that cold regions can be
paged out first.
Link: https://lkml.kernel.org/r/20211019150731.16699-9-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes DAMON apply schemes to regions having higher priority first,
if it cannot apply schemes to all regions due to the quotas.
The prioritization function should be implemented in the monitoring
primitives. Those would commonly calculate the priority of the region
using attributes of regions, namely 'size', 'nr_accesses', and 'age'.
For example, some primitive would calculate the priority of each region
using a weighted sum of 'nr_accesses' and 'age' of the region.
The optimal weights would depend on give environments, so this makes
those customizable. Nevertheless, the score calculation functions are
only encouraged to respect the weights, not mandated.
Link: https://lkml.kernel.org/r/20211019150731.16699-8-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes the debugfs interface of DAMON support the scheme quotas by
chaning the format of the input for the schemes file.
Link: https://lkml.kernel.org/r/20211019150731.16699-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size quota feature of DAMOS is useful for IO resource-critical
systems, but not so intuitive for CPU time-critical systems. Systems
using zram or zswap-like swap device would be examples.
To provide another intuitive ways for such systems, this implements
time-based quota for DAMON-based Operation Schemes. If the quota is
set, DAMOS tries to use only up to the user-defined quota of CPU time
within a given time window.
Link: https://lkml.kernel.org/r/20211019150731.16699-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If DAMOS has stopped applying action in the middle of a group of memory
regions due to its size quota, it starts the work again from the
beginning of the address space in the next charge window. If there is a
huge memory region at the beginning of the address space and it fulfills
the scheme's target data access pattern always, the action will applied
to only the region.
This mitigates the case by skipping memory regions that charged in
current charge window at the beginning of next charge window.
Link: https://lkml.kernel.org/r/20211019150731.16699-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There could be arbitrarily large memory regions fulfilling the target
data access pattern of a DAMON-based operation scheme. In the case,
applying the action of the scheme could incur too high overhead. To
provide an intuitive way for avoiding it, this implements a feature
called size quota. If the quota is set, DAMON tries to apply the action
only up to the given amount of memory regions within a given time
window.
Link: https://lkml.kernel.org/r/20211019150731.16699-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduction
============
This patchset 1) makes the engine for general data access
pattern-oriented memory management (DAMOS) be more useful for production
environments, and 2) implements a static kernel module for lightweight
proactive reclamation using the engine.
Proactive Reclamation
---------------------
On general memory over-committed systems, proactively reclaiming cold
pages helps saving memory and reducing latency spikes that incurred by
the direct reclaim or the CPU consumption of kswapd, while incurring
only minimal performance degradation[2].
A Free Pages Reporting[8] based memory over-commit virtualization system
would be one more specific use case. In the system, the guest VMs
reports their free memory to host, and the host reallocates the reported
memory to other guests. As a result, the system's memory utilization
can be maximized. However, the guests could be not so memory-frugal,
because some kernel subsystems and user-space applications are designed
to use as much memory as available. Then, guests would report only
small amount of free memory to host, results in poor memory utilization.
Running the proactive reclamation in such guests could help mitigating
this problem.
Google has also implemented this idea and using it in their data center.
They further proposed upstreaming it in LSFMM'19, and "the general
consensus was that, while this sort of proactive reclaim would be useful
for a number of users, the cost of this particular solution was too high
to consider merging it upstream"[3]. The cost mainly comes from the
coldness tracking. Roughly speaking, the implementation periodically
scans the 'Accessed' bit of each page. For the reason, the overhead
linearly increases as the size of the memory and the scanning frequency
grows. As a result, Google is known to dedicating one CPU for the work.
That's a reasonable option to someone like Google, but it wouldn't be so
to some others.
DAMON and DAMOS: An engine for data access pattern-oriented memory management
-----------------------------------------------------------------------------
DAMON[4] is a framework for general data access monitoring. Its
adaptive monitoring overhead control feature minimizes its monitoring
overhead. It also let the upper-bound of the overhead be configurable
by clients, regardless of the size of the monitoring target memory.
While monitoring 70 GiB memory of a production system every 5
milliseconds, it consumes less than 1% single CPU time. For this, it
could sacrify some of the quality of the monitoring results.
Nevertheless, the lower-bound of the quality is configurable, and it
uses a best-effort algorithm for better quality. Our test results[5]
show the quality is practical enough. From the production system
monitoring, we were able to find a 4 KiB region in the 70 GiB memory
that shows highest access frequency.
We normally don't monitor the data access pattern just for fun but to
improve something like memory management. Proactive reclamation is one
such usage. For such general cases, DAMON provides a feature called
DAMon-based Operation Schemes (DAMOS)[6]. It makes DAMON an engine for
general data access pattern oriented memory management. Using this,
clients can ask DAMON to find memory regions of specific data access
pattern and apply some memory management action (e.g., page out, move to
head of the LRU list, use huge page, ...). We call the request
'scheme'.
Proactive Reclamation on top of DAMON/DAMOS
-------------------------------------------
Therefore, by using DAMON for the cold pages detection, the proactive
reclamation's monitoring overhead issue can be solved. Actually, we
previously implemented a version of proactive reclamation using DAMOS
and achieved noticeable improvements with our evaluation setup[5].
Nevertheless, it more for a proof-of-concept, rather than production
uses. It supports only virtual address spaces of processes, and require
additional tuning efforts for given workloads and the hardware. For the
tuning, we introduced a simple auto-tuning user space tool[8]. Google
is also known to using a ML-based similar approach for their fleets[2].
But, making it just works with intuitive knobs in the kernel would be
helpful for general users.
To this end, this patchset improves DAMOS to be ready for such
production usages, and implements another version of the proactive
reclamation, namely DAMON_RECLAIM, on top of it.
DAMOS Improvements: Aggressiveness Control, Prioritization, and Watermarks
--------------------------------------------------------------------------
First of all, the current version of DAMOS supports only virtual address
spaces. This patchset makes it supports the physical address space for
the page out action.
Next major problem of the current version of DAMOS is the lack of the
aggressiveness control, which can results in arbitrary overhead. For
example, if huge memory regions having the data access pattern of
interest are found, applying the requested action to all of the regions
could incur significant overhead. It can be controlled by tuning the
target data access pattern with manual or automated approaches[2,7].
But, some people would prefer the kernel to just work with only
intuitive tuning or default values.
For such cases, this patchset implements a safeguard, namely time/size
quota. Using this, the clients can specify up to how much time can be
used for applying the action, and/or up to how much memory regions the
action can be applied within a user-specified time duration. A followup
question is, to which memory regions should the action applied within
the limits? We implement a simple regions prioritization mechanism for
each action and make DAMOS to apply the action to high priority regions
first. It also allows clients tune the prioritization mechanism to use
different weights for size, access frequency, and age of memory regions.
This means we could use not only LRU but also LFU or some fancy
algorithms like CAR[9] with lightweight overhead.
Though DAMON is lightweight, someone would want to remove even the cold
pages monitoring overhead when it is unnecessary. Currently, it should
manually turned on and off by clients, but some clients would simply
want to turn it on and off based on some metrics like free memory ratio
or memory fragmentation. For such cases, this patchset implements a
watermarks-based automatic activation feature. It allows the clients
configure the metric of their interest, and three watermarks of the
metric. If the metric is higher than the high watermark or lower than
the low watermark, the scheme is deactivated. If the metric is lower
than the mid watermark but higher than the low watermark, the scheme is
activated.
DAMON-based Reclaim
-------------------
Using the improved version of DAMOS, this patchset implements a static
kernel module called 'damon_reclaim'. It finds memory regions that
didn't accessed for specific time duration and page out. Consuming too
much CPU for the paging out operations, or doing pageout too frequently
can be critical for systems configuring their swap devices with
software-defined in-memory block devices like zram/zswap or total number
of writes limited devices like SSDs, respectively. To avoid the
problems, the time/size quotas can be configured. Under the quotas, it
pages out memory regions that didn't accessed longer first. Also, to
remove the monitoring overhead under peaceful situation, and to fall
back to the LRU-list based page granularity reclamation when it doesn't
make progress, the three watermarks based activation mechanism is used,
with the free memory ratio as the watermark metric.
For convenient configurations, it provides several module parameters.
Using these, sysadmins can enable/disable it, and tune its parameters
including the coldness identification time threshold, the time/size
quotas and the three watermarks.
Evaluation
==========
In short, DAMON_RECLAIM with 50ms/s time quota and regions
prioritization on v5.15-rc5 Linux kernel with ZRAM swap device achieves
38.58% memory saving with only 1.94% runtime overhead. For this,
DAMON_RECLAIM consumes only 4.97% of single CPU time.
Setup
-----
We evaluate DAMON_RECLAIM to show how each of the DAMOS improvements
make effect. For this, we measure DAMON_RECLAIM's CPU consumption,
entire system memory footprint, total number of major page faults, and
runtime of 24 realistic workloads in PARSEC3 and SPLASH-2X benchmark
suites on my QEMU/KVM based virtual machine. The virtual machine runs
on an i3.metal AWS instance, has 130GiB memory, and runs a linux kernel
built on latest -mm tree[1] plus this patchset. It also utilizes a 4
GiB ZRAM swap device. We repeats the measurement 5 times and use
averages.
[1] https://github.com/hnaz/linux-mm/tree/v5.15-rc5-mmots-2021-10-13-19-55
Detailed Results
----------------
The results are summarized in the below table.
With coldness identification threshold of 5 seconds, DAMON_RECLAIM
without the time quota-based speed limit achieves 47.21% memory saving,
but incur 4.59% runtime slowdown to the workloads on average. For this,
DAMON_RECLAIM consumes about 11.28% single CPU time.
Applying time quotas of 200ms/s, 50ms/s, and 10ms/s without the regions
prioritization reduces the slowdown to 4.89%, 2.65%, and 1.5%,
respectively. Time quota of 200ms/s (20%) makes no real change compared
to the quota unapplied version, because the quota unapplied version
consumes only 11.28% CPU time. DAMON_RECLAIM's CPU utilization also
similarly reduced: 11.24%, 5.51%, and 2.01% of single CPU time. That
is, the overhead is proportional to the speed limit. Nevertheless, it
also reduces the memory saving because it becomes less aggressive. In
detail, the three variants show 48.76%, 37.83%, and 7.85% memory saving,
respectively.
Applying the regions prioritization (page out regions that not accessed
longer first within the time quota) further reduces the performance
degradation. Runtime slowdowns and total number of major page faults
increase has been 4.89%/218,690% -> 4.39%/166,136% (200ms/s),
2.65%/111,886% -> 1.94%/59,053% (50ms/s), and 1.5%/34,973.40% ->
2.08%/8,781.75% (10ms/s). The runtime under 10ms/s time quota has
increased with prioritization, but apparently that's under the margin of
error.
time quota prioritization memory_saving cpu_util slowdown pgmajfaults overhead
N N 47.21% 11.28% 4.59% 194,802%
200ms/s N 48.76% 11.24% 4.89% 218,690%
50ms/s N 37.83% 5.51% 2.65% 111,886%
10ms/s N 7.85% 2.01% 1.5% 34,793.40%
200ms/s Y 50.08% 10.38% 4.39% 166,136%
50ms/s Y 38.58% 4.97% 1.94% 59,053%
10ms/s Y 3.63% 1.73% 2.08% 8,781.75%
Baseline and Complete Git Trees
===============================
The patches are based on the latest -mm tree
(v5.15-rc5-mmots-2021-10-13-19-55). You can also clone the complete git tree
from:
$ git clone git://github.com/sjp38/linux -b damon_reclaim/patches/v1
The web is also available:
https://git.kernel.org/pub/scm/linux/kernel/git/sj/linux.git/tag/?h=damon_reclaim/patches/v1
Sequence Of Patches
===================
The first patch makes DAMOS support the physical address space for the
page out action. Following five patches (patches 2-6) implement the
time/size quotas. Next four patches (patches 7-10) implement the memory
regions prioritization within the limit. Then, three following patches
(patches 11-13) implement the watermarks-based schemes activation.
Finally, the last two patches (patches 14-15) implement and document the
DAMON-based reclamation using the advanced DAMOS.
[1] https://www.kernel.org/doc/html/v5.15-rc1/vm/damon/index.html
[2] https://research.google/pubs/pub48551/
[3] https://lwn.net/Articles/787611/
[4] https://damonitor.github.io
[5] https://damonitor.github.io/doc/html/latest/vm/damon/eval.html
[6] https://lore.kernel.org/linux-mm/20211001125604.29660-1-sj@kernel.org/
[7] https://github.com/awslabs/damoos
[8] https://www.kernel.org/doc/html/latest/vm/free_page_reporting.html
[9] https://www.usenix.org/conference/fast-04/car-clock-adaptive-replacement
This patch (of 15):
This makes the DAMON primitives for physical address space support the
pageout action for DAMON-based Operation Schemes. With this commit,
hence, users can easily implement system-level data access-aware
reclamations using DAMOS.
[sj@kernel.org: fix missing-prototype build warning]
Link: https://lkml.kernel.org/r/20211025064220.13904-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211019150731.16699-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211019150731.16699-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In some functions, it's unnecessary to declare 'err' and 'ret' variables
at the same time. This patch mainly to simplify the issue of such
declarations by reusing one variable.
Link: https://lkml.kernel.org/r/20211014073014.35754-1-sj@kernel.org
Signed-off-by: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The only usage of these structs is to pass their addresses to
walk_page_range(), which takes a pointer to const mm_walk_ops as
argument. Make them const to allow the compiler to put them in
read-only memory.
Link: https://lkml.kernel.org/r/20211014075042.17174-2-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes the 'damon-dbgfs' to support the physical memory monitoring,
in addition to the virtual memory monitoring.
Users can do the physical memory monitoring by writing a special
keyword, 'paddr' to the 'target_ids' debugfs file. Then, DAMON will
check the special keyword and configure the monitoring context to run
with the primitives for the physical address space.
Unlike the virtual memory monitoring, the monitoring target region will
not be automatically set. Therefore, users should also set the
monitoring target address region using the 'init_regions' debugfs file.
Also, note that the physical memory monitoring will not automatically
terminated. The user should explicitly turn off the monitoring by
writing 'off' to the 'monitor_on' debugfs file.
Link: https://lkml.kernel.org/r/20211012205711.29216-7-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This implements the monitoring primitives for the physical memory
address space. Internally, it uses the PTE Accessed bit, similar to
that of the virtual address spaces monitoring primitives. It supports
only user memory pages, as idle pages tracking does. If the monitoring
target physical memory address range contains non-user memory pages,
access check of the pages will do nothing but simply treat the pages as
not accessed.
Link: https://lkml.kernel.org/r/20211012205711.29216-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves functions in the default virtual address spaces monitoring
primitives that commonly usable from other address spaces like physical
address space into a header file. Those will be reused by the physical
address space monitoring primitives which will be implemented by the
following commit.
[sj@kernel.org: include 'highmem.h' to fix a build failure]
Link: https://lkml.kernel.org/r/20211014110848.5204-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211012205711.29216-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds another test case for the new feature, 'init_regions'.
Link: https://lkml.kernel.org/r/20211012205711.29216-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "DAMON: Support Physical Memory Address Space Monitoring:.
DAMON currently supports only virtual address spaces monitoring. It can
be easily extended for various use cases and address spaces by
configuring its monitoring primitives layer to use appropriate
primitives implementations, though. This patchset implements monitoring
primitives for the physical address space monitoring using the
structure.
The first 3 patches allow the user space users manually set the
monitoring regions. The 1st patch implements the feature in the
'damon-dbgfs'. Then, patches for adding a unit tests (the 2nd patch)
and updating the documentation (the 3rd patch) follow.
Following 4 patches implement the physical address space monitoring
primitives. The 4th patch makes some primitive functions for the
virtual address spaces primitives reusable. The 5th patch implements
the physical address space monitoring primitives. The 6th patch links
the primitives to the 'damon-dbgfs'. Finally, 7th patch documents this
new features.
This patch (of 7):
Some 'damon-dbgfs' users would want to monitor only a part of the entire
virtual memory address space. The program interface users in the kernel
space could use '->before_start()' callback or set the regions inside
the context struct as they want, but 'damon-dbgfs' users cannot.
For that reason, this introduces a new debugfs file called
'init_region'. 'damon-dbgfs' users can specify which initial monitoring
target address regions they want by writing special input to the file.
The input should describe each region in each line in the below form:
<pid> <start address> <end address>
Note that the regions will be updated to cover entire memory mapped
regions after a 'regions update interval' is passed. If you want the
regions to not be updated after the initial setting, you could set the
interval as a very long time, say, a few decades.
Link: https://lkml.kernel.org/r/20211012205711.29216-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211012205711.29216-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rienjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To tune the DAMON-based operation schemes, knowing how many and how
large regions are affected by each of the schemes will be helful. Those
stats could be used for not only the tuning, but also monitoring of the
working set size and the number of regions, if the scheme does not
change the program behavior too much.
For the reason, this implements the statistics for the schemes. The
total number and size of the regions that each scheme is applied are
exported to users via '->stat_count' and '->stat_sz' of 'struct damos'.
Admins can also check the number by reading 'schemes' debugfs file. The
last two integers now represents the stats. To allow collecting the
stats without changing the program behavior, this also adds new scheme
action, 'DAMOS_STAT'. Note that 'DAMOS_STAT' is not only making no
memory operation actions, but also does not reset the age of regions.
Link: https://lkml.kernel.org/r/20211001125604.29660-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes 'damon-dbgfs' to support the data access monitoring oriented
memory management schemes. Users can read and update the schemes using
``<debugfs>/damon/schemes`` file. The format is::
<min/max size> <min/max access frequency> <min/max age> <action>
Link: https://lkml.kernel.org/r/20211001125604.29660-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes DAMON's default primitives for virtual address spaces to
support DAMON-based Operation Schemes (DAMOS) by implementing actions
application functions and registering it to the monitoring context. The
implementation simply links 'madvise()' for related DAMOS actions. That
is, 'madvise(MADV_WILLNEED)' is called for 'WILLNEED' DAMOS action and
similar for other actions ('COLD', 'PAGEOUT', 'HUGEPAGE', 'NOHUGEPAGE').
So, the kernel space DAMON users can now use the DAMON-based
optimizations with only small amount of code.
Link: https://lkml.kernel.org/r/20211001125604.29660-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In many cases, users might use DAMON for simple data access aware memory
management optimizations such as applying an operation scheme to a
memory region of a specific size having a specific access frequency for
a specific time. For example, "page out a memory region larger than 100
MiB but having a low access frequency more than 10 minutes", or "Use THP
for a memory region larger than 2 MiB having a high access frequency for
more than 2 seconds".
Most simple form of the solution would be doing offline data access
pattern profiling using DAMON and modifying the application source code
or system configuration based on the profiling results. Or, developing
a daemon constructed with two modules (one for access monitoring and the
other for applying memory management actions via mlock(), madvise(),
sysctl, etc) is imaginable.
To avoid users spending their time for implementation of such simple
data access monitoring-based operation schemes, this makes DAMON to
handle such schemes directly. With this change, users can simply
specify their desired schemes to DAMON. Then, DAMON will automatically
apply the schemes to the user-specified target processes.
Each of the schemes is composed with conditions for filtering of the
target memory regions and desired memory management action for the
target. Specifically, the format is::
<min/max size> <min/max access frequency> <min/max age> <action>
The filtering conditions are size of memory region, number of accesses
to the region monitored by DAMON, and the age of the region. The age of
region is incremented periodically but reset when its addresses or
access frequency has significantly changed or the action of a scheme was
applied. For the action, current implementation supports a few of
madvise()-like hints, ``WILLNEED``, ``COLD``, ``PAGEOUT``, ``HUGEPAGE``,
and ``NOHUGEPAGE``.
Because DAMON supports various address spaces and application of the
actions to a monitoring target region is dependent to the type of the
target address space, the application code should be implemented by each
primitives and registered to the framework. Note that this only
implements the framework part. Following commit will implement the
action applications for virtual address spaces primitives.
Link: https://lkml.kernel.org/r/20211001125604.29660-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Implement Data Access Monitoring-based Memory Operation Schemes".
Introduction
============
DAMON[1] can be used as a primitive for data access aware memory
management optimizations. For that, users who want such optimizations
should run DAMON, read the monitoring results, analyze it, plan a new
memory management scheme, and apply the new scheme by themselves. Such
efforts will be inevitable for some complicated optimizations.
However, in many other cases, the users would simply want the system to
apply a memory management action to a memory region of a specific size
having a specific access frequency for a specific time. For example,
"page out a memory region larger than 100 MiB keeping only rare accesses
more than 2 minutes", or "Do not use THP for a memory region larger than
2 MiB rarely accessed for more than 1 seconds".
To make the works easier and non-redundant, this patchset implements a
new feature of DAMON, which is called Data Access Monitoring-based
Operation Schemes (DAMOS). Using the feature, users can describe the
normal schemes in a simple way and ask DAMON to execute those on its
own.
[1] https://damonitor.github.io
Evaluations
===========
DAMOS is accurate and useful for memory management optimizations. An
experimental DAMON-based operation scheme for THP, 'ethp', removes
76.15% of THP memory overheads while preserving 51.25% of THP speedup.
Another experimental DAMON-based 'proactive reclamation' implementation,
'prcl', reduces 93.38% of residential sets and 23.63% of system memory
footprint while incurring only 1.22% runtime overhead in the best case
(parsec3/freqmine).
NOTE that the experimental THP optimization and proactive reclamation
are not for production but only for proof of concepts.
Please refer to the showcase web site's evaluation document[1] for
detailed evaluation setup and results.
[1] https://damonitor.github.io/doc/html/v34/vm/damon/eval.html
Long-term Support Trees
-----------------------
For people who want to test DAMON but using LTS kernels, there are
another couple of trees based on two latest LTS kernels respectively and
containing the 'damon/master' backports.
- For v5.4.y: https://git.kernel.org/sj/h/damon/for-v5.4.y
- For v5.10.y: https://git.kernel.org/sj/h/damon/for-v5.10.y
Sequence Of Patches
===================
The 1st patch accounts age of each region. The 2nd patch implements the
core of the DAMON-based operation schemes feature. The 3rd patch makes
the default monitoring primitives for virtual address spaces to support
the schemes. From this point, the kernel space users can use DAMOS.
The 4th patch exports the feature to the user space via the debugfs
interface. The 5th patch implements schemes statistics feature for
easier tuning of the schemes and runtime access pattern analysis, and
the 6th patch adds selftests for these changes. Finally, the 7th patch
documents this new feature.
This patch (of 7):
DAMON can be used for data access pattern aware memory management
optimizations. For that, users should run DAMON, read the monitoring
results, analyze it, plan a new memory management scheme, and apply the
new scheme by themselves. It would not be too hard, but still require
some level of effort. For complicated cases, this effort is inevitable.
That said, in many cases, users would simply want to apply an actions to
a memory region of a specific size having a specific access frequency
for a specific time. For example, "page out a memory region larger than
100 MiB but having a low access frequency more than 10 minutes", or "Use
THP for a memory region larger than 2 MiB having a high access frequency
for more than 2 seconds".
For such optimizations, users will need to first account the age of each
region themselves. To reduce such efforts, this implements a simple age
account of each region in DAMON. For each aggregation step, DAMON
compares the access frequency with that from last aggregation and reset
the age of the region if the change is significant. Else, the age is
incremented. Also, in case of the merge of regions, the region
size-weighted average of the ages is set as the age of merged new
region.
Link: https://lkml.kernel.org/r/20211001125604.29660-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211001125604.29660-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Marco Elver <elver@google.com>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Greg Thelen <gthelen@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: David Rienjes <rientjes@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently a plain integer is being used to nullify the pointer
ctx->kdamond. Use NULL instead. Cleans up sparse warning:
mm/damon/core.c:317:40: warning: Using plain integer as NULL pointer
Link: https://lkml.kernel.org/r/20210925215908.181226-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Just get the pid by 'current->pid'. Meanwhile, to be symmetrical make
the 'starts' and 'finishes' logs both use debug level.
Link: https://lkml.kernel.org/r/20210927232432.17750-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Just return from the kthread function.
Link: https://lkml.kernel.org/r/20210927232421.17694-1-changbin.du@gmail.com
Signed-off-by: Changbin Du <changbin.du@gmail.com>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Logging of kdamond startup is using 'pr_info()' unnecessarily. This
makes it to use 'pr_debug()' instead.
Link: https://lkml.kernel.org/r/20210917123958.3819-6-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Correct a singular versus plural grammar mistake in the help text for
the DAMON_VADDR config symbol.
Link: https://lkml.kernel.org/r/20210914073451.3883834-1-geert@linux-m68k.org
Fixes: 3f49584b26 ("mm/damon: implement primitives for the virtual memory address spaces")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Regardless of KFENCE mode (CONFIG_KFENCE_STATIC_KEYS: either using
static keys to gate allocations, or using a simple dynamic branch),
always use a static branch to avoid the dynamic branch in kfence_alloc()
if KFENCE was disabled at boot.
For CONFIG_KFENCE_STATIC_KEYS=n, this now avoids the dynamic branch if
KFENCE was disabled at boot.
To simplify, also unifies the location where kfence_allocation_gate is
read-checked to just be inline in kfence_alloc().
Link: https://lkml.kernel.org/r/20211019102524.2807208-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initializing memory and setting/checking the canary bytes is relatively
expensive, and doing so in the meta->lock critical sections extends the
duration with preemption and interrupts disabled unnecessarily.
Any reads to meta->addr and meta->size in kfence_guarded_alloc() and
kfence_guarded_free() don't require locking meta->lock as long as the
object is removed from the freelist: only kfence_guarded_alloc() sets
meta->addr and meta->size after removing it from the freelist, which
requires a preceding kfence_guarded_free() returning it to the list or
the initial state.
Therefore move reads to meta->addr and meta->size, including expensive
memory initialization using them, out of meta->lock critical sections.
Link: https://lkml.kernel.org/r/20210930153706.2105471-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the new kunit_skip() to skip tests if requirements were not met. It
makes it easier to see in KUnit's summary if there were skipped tests.
Link: https://lkml.kernel.org/r/20210922182541.1372400-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of KFENCE's main design principles is that with increasing uptime,
allocation coverage increases sufficiently to detect previously
undetected bugs.
We have observed that frequent long-lived allocations of the same source
(e.g. pagecache) tend to permanently fill up the KFENCE pool with
increasing system uptime, thus breaking the above requirement. The
workaround thus far had been increasing the sample interval and/or
increasing the KFENCE pool size, but is no reliable solution.
To ensure diverse coverage of allocations, limit currently covered
allocations of the same source once pool utilization reaches 75%
(configurable via `kfence.skip_covered_thresh`) or above. The effect is
retaining reasonable allocation coverage when the pool is close to full.
A side-effect is that this also limits frequent long-lived allocations
of the same source filling up the pool permanently.
Uniqueness of an allocation for coverage purposes is based on its
(partial) allocation stack trace (the source). A Counting Bloom filter
is used to check if an allocation is covered; if the allocation is
currently covered, the allocation is skipped by KFENCE.
Testing was done using:
(a) a synthetic workload that performs frequent long-lived
allocations (default config values; sample_interval=1;
num_objects=63), and
(b) normal desktop workloads on an otherwise idle machine where
the problem was first reported after a few days of uptime
(default config values).
In both test cases the sampled allocation rate no longer drops to zero
at any point. In the case of (b) we observe (after 2 days uptime) 15%
unique allocations in the pool, 77% pool utilization, with 20% "skipped
allocations (covered)".
[elver@google.com: simplify and just use hash_32(), use more random stack_hash_seed]
Link: https://lkml.kernel.org/r/YU3MRGaCaJiYht5g@elver.google.com
[elver@google.com: fix 32 bit]
Link: https://lkml.kernel.org/r/20210923104803.2620285-4-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the saving of the stack trace of allocations into __kfence_alloc(),
so that the stack entries array can be used outside of
kfence_guarded_alloc() and we avoid potentially unwinding the stack
multiple times.
Link: https://lkml.kernel.org/r/20210923104803.2620285-3-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Maintain a counter to count allocations that are skipped due to being
incompatible (oversized, incompatible gfp flags) or no capacity.
This is to compute the fraction of allocations that could not be
serviced by KFENCE, which we expect to be rare.
Link: https://lkml.kernel.org/r/20210923104803.2620285-2-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Alexander Potapenko <glider@google.com>
Cc: Aleksandr Nogikh <nogikh@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Taras Madan <tarasmadan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This has served its purpose and is no longer used. All usercopy
violations appear to have been handled by now, any remaining instances
(or new bugs) will cause copies to be rejected.
This isn't a direct revert of commit 2d891fbc3b ("usercopy: Allow
strict enforcement of whitelists"); since usercopy_fallback is
effectively 0, the fallback handling is removed too.
This also removes the usercopy_fallback module parameter on slab_common.
Link: https://github.com/KSPP/linux/issues/153
Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org
Signed-off-by: Stephen Kitt <steve@sk2.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Joel Stanley <joel@jms.id.au> [defconfig change]
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E . Hallyn" <serge@hallyn.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmap_atomic() is being deprecated in favor of kmap_local_page().
Replace the uses of kmap_atomic() within the highmem code.
On profiling clear_huge_page() using ftrace an improvement of 62% was
observed on the below setup.
Setup:-
Below data has been collected on Qualcomm's SM7250 SoC THP enabled
(kernel v4.19.113) with only CPU-0(Cortex-A55) and CPU-7(Cortex-A76)
switched on and set to max frequency, also DDR set to perf governor.
FTRACE Data:-
Base data:-
Number of iterations: 48
Mean of allocation time: 349.5 us
std deviation: 74.5 us
v4 data:-
Number of iterations: 48
Mean of allocation time: 131 us
std deviation: 32.7 us
The following simple userspace experiment to allocate
100MB(BUF_SZ) of pages and writing to it gave us a good insight,
we observed an improvement of 42% in allocation and writing timings.
-------------------------------------------------------------
Test code snippet
-------------------------------------------------------------
clock_start();
buf = malloc(BUF_SZ); /* Allocate 100 MB of memory */
for(i=0; i < BUF_SZ_PAGES; i++)
{
*((int *)(buf + (i*PAGE_SIZE))) = 1;
}
clock_end();
-------------------------------------------------------------
Malloc test timings for 100MB anon allocation:-
Base data:-
Number of iterations: 100
Mean of allocation time: 31831 us
std deviation: 4286 us
v4 data:-
Number of iterations: 100
Mean of allocation time: 18193 us
std deviation: 4915 us
[willy@infradead.org: fix zero_user_segments()]
Link: https://lkml.kernel.org/r/YYVhHCJcm2DM2G9u@casper.infradead.org
Link: https://lkml.kernel.org/r/20210204073255.20769-2-prathu.baronia@oneplus.com
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Prathu Baronia <prathu.baronia@oneplus.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is one possible race window between zs_pool_dec_isolated() and
zs_unregister_migration() because wait_for_isolated_drain() checks the
isolated count without holding class->lock and there is no order inside
zs_pool_dec_isolated(). Thus the below race window could be possible:
zs_pool_dec_isolated zs_unregister_migration
check pool->destroying != 0
pool->destroying = true;
smp_mb();
wait_for_isolated_drain()
wait for pool->isolated_pages == 0
atomic_long_dec(&pool->isolated_pages);
atomic_long_read(&pool->isolated_pages) == 0
Since we observe the pool->destroying (false) before atomic_long_dec()
for pool->isolated_pages, waking pool->migration_wait up is missed.
Fix this by ensure checking pool->destroying happens after the
atomic_long_dec(&pool->isolated_pages).
Link: https://lkml.kernel.org/r/20210708115027.7557-1-linmiaohe@huawei.com
Fixes: 701d678599 ("mm/zsmalloc.c: fix race condition in zs_destroy_pool")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Henry Burns <henryburns@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During migration special page table entries are installed for each page
being migrated. These entries store the pfn and associated permissions
of ptes mapping the page being migarted.
Device-private pages use special swap pte entries to distinguish
read-only vs. writeable pages which the migration code checks when
creating migration entries. Normally this follows a fast path in
migrate_vma_collect_pmd() which correctly copies the permissions of
device-private pages over to migration entries when migrating pages back
to the CPU.
However the slow-path falls back to using try_to_migrate() which
unconditionally creates read-only migration entries for device-private
pages. This leads to unnecessary double faults on the CPU as the new
pages are always mapped read-only even when they could be mapped
writeable. Fix this by correctly copying device-private permissions in
try_to_migrate_one().
Link: https://lkml.kernel.org/r/20211018045247.3128058-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's add a flag that corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED,
indicating that we're dealing with a memory region that is never
indicated in the firmware-provided memory map, but always detected and
added by a driver.
Similar to MEMBLOCK_HOTPLUG, most infrastructure has to treat such
memory regions like ordinary MEMBLOCK_NONE memory regions -- for
example, when selecting memory regions to add to the vmcore for dumping
in the crashkernel via for_each_mem_range().
However, especially kexec_file is not supposed to select such memblocks
via for_each_free_mem_range() / for_each_free_mem_range_reverse() to
place kexec images, similar to how we handle
IORESOURCE_SYSRAM_DRIVER_MANAGED without CONFIG_ARCH_KEEP_MEMBLOCK.
We'll make sure that memory hotplug code sets the flag where applicable
(IORESOURCE_SYSRAM_DRIVER_MANAGED) next. This prepares architectures
that need CONFIG_ARCH_KEEP_MEMBLOCK, such as arm64, for virtio-mem
support.
Note that kexec *must not* indicate this memory to the second kernel and
*must not* place kexec-images on this memory. Let's add a comment to
kexec_walk_memblock(), documenting how we handle MEMBLOCK_DRIVER_MANAGED
now just like using IORESOURCE_SYSRAM_DRIVER_MANAGED in
locate_mem_hole_callback() for kexec_walk_resources().
Also note that MEMBLOCK_HOTPLUG cannot be reused due to different
semantics:
MEMBLOCK_HOTPLUG: memory is indicated as "System RAM" in the
firmware-provided memory map and added to the system early during
boot; kexec *has to* indicate this memory to the second kernel and
can place kexec-images on this memory. After memory hotunplug,
kexec has to be re-armed. We mostly ignore this flag when
"movable_node" is not set on the kernel command line, because
then we're told to not care about hotunpluggability of such
memory regions.
MEMBLOCK_DRIVER_MANAGED: memory is not indicated as "System RAM" in
the firmware-provided memory map; this memory is always detected
and added to the system by a driver; memory might not actually be
physically hotunpluggable. kexec *must not* indicate this memory to
the second kernel and *must not* place kexec-images on this memory.
Link: https://lkml.kernel.org/r/20211004093605.5830-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want to specify flags when hotplugging memory. Let's prepare to pass
flags to memblock_add_node() by adjusting all existing users.
Note that when hotplugging memory the system is already up and running
and we might have concurrent memblock users: for example, while we're
hotplugging memory, kexec_file code might search for suitable memory
regions to place kexec images. It's important to add the memory
directly to memblock via a single call with the right flags, instead of
adding the memory first and apply flags later: otherwise, concurrent
memblock users might temporarily stumble over memblocks with wrong
flags, which will be important in a follow-up patch that introduces a
new flag to properly handle add_memory_driver_managed().
Link: https://lkml.kernel.org/r/20211004093605.5830-4-david@redhat.com
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shahab Vahedi <shahab@synopsys.com> [arch/arc]
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: full support for add_memory_driver_managed() with CONFIG_ARCH_KEEP_MEMBLOCK", v2.
Architectures that require CONFIG_ARCH_KEEP_MEMBLOCK=y, such as arm64,
don't cleanly support add_memory_driver_managed() yet. Most
prominently, kexec_file can still end up placing kexec images on such
driver-managed memory, resulting in undesired behavior, for example,
having kexec images located on memory not part of the firmware-provided
memory map.
Teaching kexec to not place images on driver-managed memory is
especially relevant for virtio-mem. Details can be found in commit
7b7b27214b ("mm/memory_hotplug: introduce
add_memory_driver_managed()").
Extend memblock with a new flag and set it from memory hotplug code when
applicable. This is required to fully support virtio-mem on arm64,
making also kexec_file behave like on x86-64.
This patch (of 2):
If memblock_add_node() fails, we're most probably running out of memory.
While this is unlikely to happen, it can happen and having memory added
without a memblock can be problematic for architectures that use
memblock to detect valid memory. Let's fail in a nice way instead of
silently ignoring the error.
Link: https://lkml.kernel.org/r/20211004093605.5830-1-david@redhat.com
Link: https://lkml.kernel.org/r/20211004093605.5830-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jianyong Wu <Jianyong.Wu@arm.com>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Shahab Vahedi <shahab@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't support CONFIG_MEMORY_HOTPLUG on 32 bit and consequently not
HIGHMEM. Let's remove any leftover code -- including the unused
"status_change_nid_high" field part of the memory notifier.
Link: https://lkml.kernel.org/r/20210929143600.49379-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
32 bit support is broken in various ways: for example, we can online
memory that should actually go to ZONE_HIGHMEM to ZONE_MOVABLE or in
some cases even to one of the other kernel zones.
We marked it BROKEN in commit b59d02ed08 ("mm/memory_hotplug: disable
the functionality for 32b") almost one year ago. According to that
commit it might be broken at least since 2017. Further, there is hardly
a sane use case nowadays.
Let's just depend completely on 64bit, dropping the "BROKEN" dependency
to make clear that we are not going to support it again. Next, we'll
remove some HIGHMEM leftovers from memory hotplug code to clean up.
Link: https://lkml.kernel.org/r/20210929143600.49379-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_MEMORY_HOTPLUG depends on CONFIG_SPARSEMEM, so there is no need for
CONFIG_MEMORY_HOTPLUG_SPARSE anymore; adjust all instances to use
CONFIG_MEMORY_HOTPLUG and remove CONFIG_MEMORY_HOTPLUG_SPARSE.
Link: https://lkml.kernel.org/r/20210929143600.49379-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org> [kselftest]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Oscar Salvador <osalvador@suse.de>
Cc: Alex Shi <alexs@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: Kconfig and 32 bit cleanups".
Some cleanups around CONFIG_MEMORY_HOTPLUG, including removing 32 bit
leftovers of memory hotplug support.
This patch (of 6):
SPARSEMEM is the only possible memory model for x86-64, FLATMEM is not
possible:
config ARCH_FLATMEM_ENABLE
def_bool y
depends on X86_32 && !NUMA
And X86_64_ACPI_NUMA (obviously) only supports x86-64:
config X86_64_ACPI_NUMA
def_bool y
depends on X86_64 && NUMA && ACPI && PCI
Let's just remove the CONFIG_X86_64_ACPI_NUMA dependency, as it does no
longer make sense.
Link: https://lkml.kernel.org/r/20210929143600.49379-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alex Shi <alexs@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
online_policy_to_str is only used in memory_hotplug.c and should be
defined as static.
Link: https://lkml.kernel.org/r/20210913024534.26161-1-tangyizhou@huawei.com
Signed-off-by: Tang Yizhou <tangyizhou@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KCSAN reports a data-race on v5.10 which also exists on mainline:
BUG: KCSAN: data-race in extfrag_for_order+0x33/0x2d0
race at unknown origin, with read to 0xffff9ee9bfffab48 of 8 bytes by task 34 on cpu 1:
extfrag_for_order+0x33/0x2d0
kcompactd+0x5f0/0xce0
kthread+0x1f9/0x220
ret_from_fork+0x22/0x30
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 34 Comm: kcompactd0 Not tainted 5.10.0+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
Access to zone->free_area[order].nr_free in extfrag_for_order() and
frag_show_print() is lockless. That's intentional and the stats are a
rough estimate anyway. Annotate them with data_race().
[liushixin2@huawei.com: add comments]
Link: https://lkml.kernel.org/r/20210918084655.2696522-1-liushixin2@huawei.com
Link: https://lkml.kernel.org/r/20210908015606.3999871-1-liushixin2@huawei.com
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When nommu, the arch_get_unmapped_area() will not be called, just kill
it.
Link: https://lkml.kernel.org/r/20210910061906.36299-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In fact, formated values returned by get_init_ra_size are not that
intuitive. This patch make the comments reflect its truth.
Link: https://lkml.kernel.org/r/20211019104812.135602-1-linf@wangsu.com
Signed-off-by: Lin Feng <linf@wangsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memory demotion needs to call migrate_pages() to do the jobs. And
it is controlled by a knob, however, the knob doesn't depend on
CONFIG_MIGRATION. The knob could be truned on even though MIGRATION is
disabled, this will not cause any crash since migrate_pages() would just
return -ENOSYS. But it is definitely not optimal to go through demotion
path then retry regular swap every time.
And it doesn't make too much sense to have the knob visible to the users
when !MIGRATION. Move the related code from mempolicy.[h|c] to
migrate.[h|c].
Link: https://lkml.kernel.org/r/20211015005559.246709-1-shy828301@gmail.com
Signed-off-by: Yang Shi <shy828301@gmail.com>
Acked-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to remove the need to manually keep three different files in
synch, provide a common definition of the mapping between enum
migrate_reason, and the associated strings for each enum item.
1. Use the tracing system's mapping of enums to strings, by redefining
and reusing the MIGRATE_REASON and supporting macros, and using that
to populate the string array in mm/debug.c.
2. Move enum migrate_reason to migrate_mode.h. This is not strictly
necessary for this patch, but migrate mode and migrate reason go
together, so this will slightly clarify things.
Link: https://lkml.kernel.org/r/20210922041755.141817-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Weizhao Ouyang <o451686892@gmail.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can specify the number of hugepages to allocate at boot. But the
hugepages is balanced in all nodes at present. In some scenarios, we
only need hugepages in one node. For example: DPDK needs hugepages
which are in the same node as NIC.
If DPDK needs four hugepages of 1G size in node1 and system has 16 numa
nodes we must reserve 64 hugepages on the kernel cmdline. But only four
hugepages are used. The others should be free after boot. If the
system memory is low(for example: 64G), it will be an impossible task.
So extend the hugepages parameter to support specifying hugepages on a
specific node. For example add following parameter:
hugepagesz=1G hugepages=0:1,1:3
It will allocate 1 hugepage in node0 and 3 hugepages in node1.
Link: https://lkml.kernel.org/r/20211005054729.86457-1-yaozhenguo1@gmail.com
Signed-off-by: Zhenguo Yao <yaozhenguo1@gmail.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Zhenguo Yao <yaozhenguo1@gmail.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The OOM reaper alters user address space which might theoretically alter
the snapshot if reaping is allowed to happen after the freezer quiescent
state. To this end, the reaper kthread uses wait_event_freezable()
while waiting for any work so that it cannot run while the system
freezes.
However, the current implementation doesn't respect the freezer because
all kernel threads are created with the PF_NOFREEZE flag, so they are
automatically excluded from freezing operations. This means that the
OOM reaper can race with system snapshotting if it has work to do while
the system is being frozen.
Fix this by adding a set_freezable() call which will clear the
PF_NOFREEZE flag and thus make the OOM reaper visible to the freezer.
Please note that the OOM reaper altering the snapshot this way is mostly
a theoretical concern and has not been observed in practice.
Link: https://lkml.kernel.org/r/20210921165758.6154-1-sultan@kerneltoast.com
Link: https://lkml.kernel.org/r/20210918233920.9174-1-sultan@kerneltoast.com
Fixes: aac4536355 ("mm, oom: introduce oom reaper")
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
