This patch prepares the slab allocator to handle caches having annotations
(useroffset and usersize) defining usercopy regions.
This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY
whitelisting code in the last public patch of grsecurity/PaX based on
my understanding of the code. Changes or omissions from the original
code are mine and don't reflect the original grsecurity/PaX code.
Currently, hardened usercopy performs dynamic bounds checking on slab
cache objects. This is good, but still leaves a lot of kernel memory
available to be copied to/from userspace in the face of bugs. To further
restrict what memory is available for copying, this creates a way to
whitelist specific areas of a given slab cache object for copying to/from
userspace, allowing much finer granularity of access control. Slab caches
that are never exposed to userspace can declare no whitelist for their
objects, thereby keeping them unavailable to userspace via dynamic copy
operations. (Note, an implicit form of whitelisting is the use of constant
sizes in usercopy operations and get_user()/put_user(); these bypass
hardened usercopy checks since these sizes cannot change at runtime.)
To support this whitelist annotation, usercopy region offset and size
members are added to struct kmem_cache. The slab allocator receives a
new function, kmem_cache_create_usercopy(), that creates a new cache
with a usercopy region defined, suitable for declaring spans of fields
within the objects that get copied to/from userspace.
In this patch, the default kmem_cache_create() marks the entire allocation
as whitelisted, leaving it semantically unchanged. Once all fine-grained
whitelists have been added (in subsequent patches), this will be changed
to a usersize of 0, making caches created with kmem_cache_create() not
copyable to/from userspace.
After the entire usercopy whitelist series is applied, less than 15%
of the slab cache memory remains exposed to potential usercopy bugs
after a fresh boot:
Total Slab Memory: 48074720
Usercopyable Memory: 6367532 13.2%
task_struct 0.2% 4480/1630720
RAW 0.3% 300/96000
RAWv6 2.1% 1408/64768
ext4_inode_cache 3.0% 269760/8740224
dentry 11.1% 585984/5273856
mm_struct 29.1% 54912/188448
kmalloc-8 100.0% 24576/24576
kmalloc-16 100.0% 28672/28672
kmalloc-32 100.0% 81920/81920
kmalloc-192 100.0% 96768/96768
kmalloc-128 100.0% 143360/143360
names_cache 100.0% 163840/163840
kmalloc-64 100.0% 167936/167936
kmalloc-256 100.0% 339968/339968
kmalloc-512 100.0% 350720/350720
kmalloc-96 100.0% 455616/455616
kmalloc-8192 100.0% 655360/655360
kmalloc-1024 100.0% 812032/812032
kmalloc-4096 100.0% 819200/819200
kmalloc-2048 100.0% 1310720/1310720
After some kernel build workloads, the percentage (mainly driven by
dentry and inode caches expanding) drops under 10%:
Total Slab Memory: 95516184
Usercopyable Memory: 8497452 8.8%
task_struct 0.2% 4000/1456000
RAW 0.3% 300/96000
RAWv6 2.1% 1408/64768
ext4_inode_cache 3.0% 1217280/39439872
dentry 11.1% 1623200/14608800
mm_struct 29.1% 73216/251264
kmalloc-8 100.0% 24576/24576
kmalloc-16 100.0% 28672/28672
kmalloc-32 100.0% 94208/94208
kmalloc-192 100.0% 96768/96768
kmalloc-128 100.0% 143360/143360
names_cache 100.0% 163840/163840
kmalloc-64 100.0% 245760/245760
kmalloc-256 100.0% 339968/339968
kmalloc-512 100.0% 350720/350720
kmalloc-96 100.0% 563520/563520
kmalloc-8192 100.0% 655360/655360
kmalloc-1024 100.0% 794624/794624
kmalloc-4096 100.0% 819200/819200
kmalloc-2048 100.0% 1257472/1257472
Signed-off-by: David Windsor <dave@nullcore.net>
[kees: adjust commit log, split out a few extra kmalloc hunks]
[kees: add field names to function declarations]
[kees: convert BUGs to WARNs and fail closed]
[kees: add attack surface reduction analysis to commit log]
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-xfs@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Christoph Lameter <cl@linux.com>
This refactors the hardened usercopy code so that failure reporting can
happen within the checking functions instead of at the top level. This
simplifies the return value handling and allows more details and offsets
to be included in the report. Having the offset can be much more helpful
in understanding hardened usercopy bugs.
Signed-off-by: Kees Cook <keescook@chromium.org>
In preparation for refactoring the usercopy checks to pass offset to
the hardened usercopy report, this renames report_usercopy() to the
more accurate usercopy_abort(), marks it as noreturn because it is,
adds a hopefully helpful comment for anyone investigating such reports,
makes the function available to the slab allocators, and adds new "detail"
and "offset" arguments.
Signed-off-by: Kees Cook <keescook@chromium.org>
Using %p was already mostly useless in the usercopy overflow reports,
so this removes it entirely to avoid confusion now that %p-hashing
is enabled.
Fixes: ad67b74d24 ("printk: hash addresses printed with %p")
Signed-off-by: Kees Cook <keescook@chromium.org>
kmemleak does one slab allocation per user allocation. So if slab fault
injection is enabled to any degree, kmemleak instantly fails to allocate
and turns itself off. However, it's useful to use kmemleak with fault
injection to find leaks on error paths. On the other hand, checking
kmemleak itself is not so useful because (1) it's a debugging tool and
(2) it has a very regular allocation pattern (basically a single
allocation site, so it either works or not).
Turn off fault injection for kmemleak allocations.
Link: http://lkml.kernel.org/r/20180109192243.19316-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
'struct page_map' is a private structure of 'struct dev_pagemap' but the
latter replicates all the same fields as the former so there isn't much
value in it. Thus drop it in favour of a completely public struct.
This is a clean up in preperation for a more generally useful
'devm_memeremap_pages' interface.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Change the calling convention so that get_dev_pagemap always consumes the
previous reference instead of doing this using an explicit earlier call to
put_dev_pagemap in the callers.
The callers will still need to put the final reference after finishing the
loop over the pages.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
There is no clear separation between the two, so merge them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
No functional changes, just untangling the call chain and document
why the altmap is passed around the hotplug code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Pass the vmem_altmap two levels down instead of needing a lookup.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking 2 levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking a few levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We can just pass this on instead of having to do a radix tree lookup
without proper locking 2 levels into the callchain.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This function isn't used by any modules, and is only to be called
from core MM code. This includes the calls for the add_pages wrapper
that might be inlined.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
similar to memdup_user(), but does *not* guarantee that result will
be physically contiguous; use only in cases where that's not a requirement
and free it with kvfree().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull vfs fixes from Al Viro:
- untangle sys_close() abuses in xt_bpf
- deal with register_shrinker() failures in sget()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix "netfilter: xt_bpf: Fix XT_BPF_MODE_FD_PINNED mode of 'xt_bpf_info_v1'"
sget(): handle failures of register_shrinker()
mm,vmscan: Make unregister_shrinker() no-op if register_shrinker() failed.
This patch converts to bio_first_bvec_all() & bio_first_page_all() for
retrieving the 1st bvec/page, and prepares for supporting multipage bvec.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In commit 83e3c48729 ("mm/sparsemem: Allocate mem_section at runtime
for CONFIG_SPARSEMEM_EXTREME=y") mem_section is allocated at runtime to
save memory.
It allocates the first dimension of array with sizeof(struct mem_section).
It costs extra memory, should be sizeof(struct mem_section *).
Fix it.
Link: http://lkml.kernel.org/r/1513932498-20350-1-git-send-email-bhe@redhat.com
Fixes: 83e3c48729 ("mm/sparsemem: Allocate mem_section at runtime for CONFIG_SPARSEMEM_EXTREME=y")
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Dave Young <dyoung@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Atsushi Kumagai <ats-kumagai@wm.jp.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>
`struct file_system_type' and alloc_anon_inode() function are defined in
fs.h, include it directly.
Link: http://lkml.kernel.org/r/20171219104219.3017-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the recent addition of hashed kernel pointers, places which need to
produce useful debug output have to specify %px, not %p. This patch
fixes all the VM debug to use %px. This is appropriate because it's
debug output that the user should never be able to trigger, and kernel
developers need to see the actual pointers.
Link: http://lkml.kernel.org/r/20171219133236.GE13680@bombadil.infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Tobin C. Harding" <me@tobin.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With latest kernel I get below bug while testing kdump:
BUG: unable to handle kernel paging request at ffffea00034b1040
IP: zero_resv_unavail+0xbd/0x126
PGD 37b98067 P4D 37b98067 PUD 37b97067 PMD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 4.15.0-rc1+ #316
Hardware name: LENOVO 20ARS1BJ02/20ARS1BJ02, BIOS GJET92WW (2.42 ) 03/03/2017
task: ffffffff81a0e4c0 task.stack: ffffffff81a00000
RIP: 0010:zero_resv_unavail+0xbd/0x126
RSP: 0000:ffffffff81a03d88 EFLAGS: 00010006
RAX: 0000000000000000 RBX: ffffea00034b1040 RCX: 0000000000000010
RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffffea00034b1040
RBP: 00000000000d2c41 R08: 00000000000000c0 R09: 0000000000000a0d
R10: 0000000000000002 R11: 0000000000007f01 R12: ffffffff81a03d90
R13: ffffea0000000000 R14: 0000000000000063 R15: 0000000000000062
FS: 0000000000000000(0000) GS:ffffffff81c73000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffea00034b1040 CR3: 0000000037609000 CR4: 00000000000606b0
Call Trace:
? free_area_init_nodes+0x640/0x664
? zone_sizes_init+0x58/0x72
? setup_arch+0xb50/0xc6c
? start_kernel+0x64/0x43d
? secondary_startup_64+0xa5/0xb0
Code: c1 e8 0c 48 39 d8 76 27 48 89 de 48 c1 e3 06 48 c7 c7 7a 87 79 81 e8 b0 c0 3e ff 4c 01 eb b9 10 00 00 00 31 c0 48 89 df 49 ff c6 <f3> ab eb bc 6a 00 49 c7 c0 f0 93 d1 81 31 d2 83 ce ff 41 54 49
RIP: zero_resv_unavail+0xbd/0x126 RSP: ffffffff81a03d88
CR2: ffffea00034b1040
---[ end trace f5ba9e8f73c7ee26 ]---
This is introduced by commit a4a3ede213 ("mm: zero reserved and
unavailable struct pages").
The reason is some efi reserved boot ranges is not reported in E820 ram.
In my case it is a bgrt buffer:
efi: mem00: [Boot Data |RUN| | | | | | | |WB|WT|WC|UC] range=[0x00000000d2c41000-0x00000000d2c85fff] (0MB)
Use "add_efi_memmap" can workaround the problem with another fix:
http://lkml.kernel.org/r/20171130052327.GA3500@dhcp-128-65.nay.redhat.com
In zero_resv_unavail it would be better to check pfn_valid first before
zero the page struct. This fixes the problem and potential other
similar problems. Also as Pavel Tatashin suggested checks pfn_valid at
the beginning of the section.
The range is backed by real memory. The memory range is efi "Boot
Service Data", that means after ExitBootServices() these ranges can be
used as system ram. But some of them need to be reserved, for example
the bgrt image address in an acpi table, if the image memory is freed
then kexec reboot will fail because kexec inherit same acpi table to
initialize the driver.
Link: http://lkml.kernel.org/r/20171201095048.GA3084@dhcp-128-65.nay.redhat.com
Fixes: a4a3ede213 ("mm: zero reserved and unavailable struct pages")
Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull RCU updates from Paul E. McKenney:
- Updates to use cond_resched() instead of cond_resched_rcu_qs()
where feasible (currently everywhere except in kernel/rcu and
in kernel/torture.c). Also a couple of fixes to avoid sending
IPIs to offline CPUs.
- Updates to simplify RCU's dyntick-idle handling.
- Updates to remove almost all uses of smp_read_barrier_depends()
and read_barrier_depends().
- Miscellaneous fixes.
- Torture-test updates.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull block fixes from Jens Axboe:
"It's been a few weeks, so here's a small collection of fixes that
should go into the current series.
This contains:
- NVMe pull request from Christoph, with a few important fixes.
- kyber hang fix from Omar.
- A blk-throttl fix from Shaohua, fixing a case where we double
charge a bio.
- Two call_single_data alignment fixes from me, fixing up some
unfortunate changes that went into 4.14 without being properly
reviewed on the block side (since nobody was CC'ed on the
patch...).
- A bounce buffer fix in two parts, one from me and one from Ming.
- Revert bdi debug error handling patch. It's causing boot issues for
some folks, and a week down the line, we're still no closer to a
fix. Revert this patch for now until it's figured out, then we can
retry for 4.16"
* 'for-linus' of git://git.kernel.dk/linux-block:
Revert "bdi: add error handle for bdi_debug_register"
null_blk: unalign call_single_data
block: unalign call_single_data in struct request
block-throttle: avoid double charge
block: fix blk_rq_append_bio
block: don't let passthrough IO go into .make_request_fn()
nvme: setup streams after initializing namespace head
nvme: check hw sectors before setting chunk sectors
nvme: call blk_integrity_unregister after queue is cleaned up
nvme-fc: remove double put reference if admin connect fails
nvme: set discard_alignment to zero
kyber: fix another domain token wait queue hang
This reverts commit a0747a859e.
It breaks some booting for some users, and more than a week
into this, there's still no good fix. Revert this commit
for now until a solution has been found.
Reported-by: Laura Abbott <labbott@redhat.com>
Reported-by: Bruno Wolff III <bruno@wolff.to>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This reverts commits 5c9d2d5c26, c7da82b894, and e7fe7b5cae.
We'll probably need to revisit this, but basically we should not
complicate the get_user_pages_fast() case, and checking the actual page
table protection key bits will require more care anyway, since the
protection keys depend on the exact state of the VM in question.
Particularly when doing a "remote" page lookup (ie in somebody elses VM,
not your own), you need to be much more careful than this was. Dave
Hansen says:
"So, the underlying bug here is that we now a get_user_pages_remote()
and then go ahead and do the p*_access_permitted() checks against the
current PKRU. This was introduced recently with the addition of the
new p??_access_permitted() calls.
We have checks in the VMA path for the "remote" gups and we avoid
consulting PKRU for them. This got missed in the pkeys selftests
because I did a ptrace read, but not a *write*. I also didn't
explicitly test it against something where a COW needed to be done"
It's also not entirely clear that it makes sense to check the protection
key bits at this level at all. But one possible eventual solution is to
make the get_user_pages_fast() case just abort if it sees protection key
bits set, which makes us fall back to the regular get_user_pages() case,
which then has a vma and can do the check there if we want to.
We'll see.
Somewhat related to this all: what we _do_ want to do some day is to
check the PAGE_USER bit - it should obviously always be set for user
pages, but it would be a good check to have back. Because we have no
generic way to test for it, we lost it as part of moving over from the
architecture-specific x86 GUP implementation to the generic one in
commit e585513b76 ("x86/mm/gup: Switch GUP to the generic
get_user_page_fast() implementation").
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull early_ioremap fix from Ingo Molnar:
"A boot hang fix when the EFI earlyprintk driver is enabled"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mm/early_ioremap: Fix boot hang with earlyprintk=efi,keep
David Rientjes has reported the following memory corruption while the
oom reaper tries to unmap the victims address space
BUG: Bad page map in process oom_reaper pte:6353826300000000 pmd:00000000
addr:00007f50cab1d000 vm_flags:08100073 anon_vma:ffff9eea335603f0 mapping: (null) index:7f50cab1d
file: (null) fault: (null) mmap: (null) readpage: (null)
CPU: 2 PID: 1001 Comm: oom_reaper
Call Trace:
unmap_page_range+0x1068/0x1130
__oom_reap_task_mm+0xd5/0x16b
oom_reaper+0xff/0x14c
kthread+0xc1/0xe0
Tetsuo Handa has noticed that the synchronization inside exit_mmap is
insufficient. We only synchronize with the oom reaper if
tsk_is_oom_victim which is not true if the final __mmput is called from
a different context than the oom victim exit path. This can trivially
happen from context of any task which has grabbed mm reference (e.g. to
read /proc/<pid>/ file which requires mm etc.).
The race would look like this
oom_reaper oom_victim task
mmget_not_zero
do_exit
mmput
__oom_reap_task_mm mmput
__mmput
exit_mmap
remove_vma
unmap_page_range
Fix this issue by providing a new mm_is_oom_victim() helper which
operates on the mm struct rather than a task. Any context which
operates on a remote mm struct should use this helper in place of
tsk_is_oom_victim. The flag is set in mark_oom_victim and never cleared
so it is stable in the exit_mmap path.
Debugged by Tetsuo Handa.
Link: http://lkml.kernel.org/r/20171210095130.17110-1-mhocko@kernel.org
Fixes: 2129258024 ("mm: oom: let oom_reap_task and exit_mmap run concurrently")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: David Rientjes <rientjes@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: <stable@vger.kernel.org> [4.14]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A semaphore is acquired before this check, so we must release it before
leaving.
Link: http://lkml.kernel.org/r/20171211211009.4971-1-christophe.jaillet@wanadoo.fr
Fixes: b7f0554a56 ("mm: fail get_vaddr_frames() for filesystem-dax mappings")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If CONFIG_DEBUG_SLAB/CONFIG_DEBUG_SLAB_LEAK are enabled, the slab code
prints extra debug information when e.g. corruption is detected. This
includes pointers, which are not very useful when hashed.
Fix this by using %px to print unhashed pointers instead where it makes
sense, and by removing the printing of a last user pointer referring to
code.
[geert+renesas@glider.be: v2]
Link: http://lkml.kernel.org/r/1513179267-2509-1-git-send-email-geert+renesas@glider.be
Link: http://lkml.kernel.org/r/1512641861-5113-1-git-send-email-geert+renesas@glider.be
Fixes: ad67b74d24 ("printk: hash addresses printed with %p")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 9cca35d42e ("mm, page_alloc: enable/disable IRQs once
when freeing a list of pages") we see excessive IRQ disabled times of up
to 25ms on an embedded ARM system (tracing overhead included).
This is due to graphics buffers being freed back to the system via
release_pages(). Graphics buffers can be huge, so it's not hard to hit
cases where the list of pages to free has 2048 entries. Disabling IRQs
while freeing all those pages is clearly not a good idea.
Introduce a batch limit, which allows IRQ servicing once every few
pages. The batch count is the same as used in other parts of the MM
subsystem when dealing with IRQ disabled regions.
Link: http://lkml.kernel.org/r/20171207170314.4419-1-l.stach@pengutronix.de
Fixes: 9cca35d42e ("mm, page_alloc: enable/disable IRQs once when freeing a list of pages")
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: 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>
With gcc 4.1.2:
mm/memory.o: In function `wp_huge_pmd':
memory.c:(.text+0x9b4): undefined reference to `do_huge_pmd_wp_page'
Interestingly, wp_huge_pmd() is emitted in the assembler output, but
never called.
Apparently replacing the call to pmd_write() in __handle_mm_fault() by a
call to the more complex pmd_access_permitted() reduced the ability of
the compiler to remove unused code.
Fix this by marking wp_huge_pmd() inline, like was done in commit
91a90140f9 ("mm/memory.c: mark create_huge_pmd() inline to prevent
build failure") for a similar problem.
[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/1512335500-10889-1-git-send-email-geert@linux-m68k.org
Fixes: c7da82b894 ("mm: replace pmd_write with pmd_access_permitted in fault + gup paths")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit bde5f6bc68 ("kmemleak: add scheduling point to
kmemleak_scan()") tries to rate-limit the frequency of cond_resched()
calls, but does it in a way which might incur an expensive division
operation in the inner loop. Simplify this.
Fixes: bde5f6bc68 ("kmemleak: add scheduling point to kmemleak_scan()")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull percpu fix from Tejun Heo:
"Just one patch to work around CRIS boot problem caused by a recent
change which freed a temporary boot data structure. The root cause is
on CRIS side but it doesn't seem trivial to fix. For now, work around
by skipping freeing on CRIS"
* 'for-4.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu: hack to let the CRIS architecture to boot until they clean up
earlyprintk=efi,keep does not work any more with a warning
in mm/early_ioremap.c: WARN_ON(system_state != SYSTEM_BOOTING):
Boot just hangs because of the earlyprintk within the earlyprintk
implementation code itself.
This is caused by a new introduced middle state in:
69a78ff226 ("init: Introduce SYSTEM_SCHEDULING state")
early_ioremap() is fine in both SYSTEM_BOOTING and SYSTEM_SCHEDULING
states, original condition should be updated accordingly.
Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bp@suse.de
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20171209041610.GA3249@dhcp-128-65.nay.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Commit 4675ff05de ("kmemcheck: rip it out") has removed the code but
for some reason SPDX header stayed in place. This looks like a rebase
mistake in the mmotm tree or the merge mistake. Let's drop those
leftovers as well.
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because READ_ONCE() now implies smp_read_barrier_depends(), the
smp_read_barrier_depends() in get_ksm_page() is now redundant.
This commit removes it and updates the comments.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: <linux-mm@kvack.org>
The only caller that doesn't pass true in it is get_user_pages() and
it passes NULL in locked. The only place where we check it is
if (notify_locked && lock_dropped && *locked)
and lock_dropped can become true only if we have locked != NULL.
In other words, the second part of condition will be false when
called by get_user_pages().
Just get rid of the argument and turn the condition into
if (lock_dropped && *locked)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Equivalent transformation - the only place in __get_user_pages_locked()
where we look at notify_drop argument is
if (notify_drop && lock_dropped && *locked) {
up_read(&mm->mmap_sem);
*locked = 0;
}
in the very end. Changing notify_drop from false to true won't change
behaviour unless *locked is non-zero. The caller is
ret = __get_user_pages_locked(current, mm, start, nr_pages, pages, NULL,
&locked, false, gup_flags | FOLL_TOUCH);
if (locked)
up_read(&mm->mmap_sem);
so in that case the original kernel would have done up_read() right after
return from __get_user_pages_locked(), while the modified one would've done
it right before the return.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull block fixes from Jens Axboe:
"A selection of fixes/changes that should make it into this series.
This contains:
- NVMe, two merges, containing:
- pci-e, rdma, and fc fixes
- Device quirks
- Fix for a badblocks leak in null_blk
- bcache fix from Rui Hua for a race condition regression where
-EINTR was returned to upper layers that didn't expect it.
- Regression fix for blktrace for a bug introduced in this series.
- blktrace cleanup for cgroup id.
- bdi registration error handling.
- Small series with cleanups for blk-wbt.
- Various little fixes for typos and the like.
Nothing earth shattering, most important are the NVMe and bcache fixes"
* 'for-linus' of git://git.kernel.dk/linux-block: (34 commits)
nvme-pci: fix NULL pointer dereference in nvme_free_host_mem()
nvme-rdma: fix memory leak during queue allocation
blktrace: fix trace mutex deadlock
nvme-rdma: Use mr pool
nvme-rdma: Check remotely invalidated rkey matches our expected rkey
nvme-rdma: wait for local invalidation before completing a request
nvme-rdma: don't complete requests before a send work request has completed
nvme-rdma: don't suppress send completions
bcache: check return value of register_shrinker
bcache: recover data from backing when data is clean
bcache: Fix building error on MIPS
bcache: add a comment in journal bucket reading
nvme-fc: don't use bit masks for set/test_bit() numbers
blk-wbt: fix comments typo
blk-wbt: move wbt_clear_stat to common place in wbt_done
blk-sysfs: remove NULL pointer checking in queue_wb_lat_store
blk-wbt: remove duplicated setting in wbt_init
nvme-pci: add quirk for delay before CHK RDY for WDC SN200
block: remove useless assignment in bio_split
null_blk: fix dev->badblocks leak
...
Mergr misc fixes from Andrew Morton:
"28 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
fs/hugetlbfs/inode.c: change put_page/unlock_page order in hugetlbfs_fallocate()
mm/hugetlb: fix NULL-pointer dereference on 5-level paging machine
autofs: revert "autofs: fix AT_NO_AUTOMOUNT not being honored"
autofs: revert "autofs: take more care to not update last_used on path walk"
fs/fat/inode.c: fix sb_rdonly() change
mm, memcg: fix mem_cgroup_swapout() for THPs
mm: migrate: fix an incorrect call of prep_transhuge_page()
kmemleak: add scheduling point to kmemleak_scan()
scripts/bloat-o-meter: don't fail with division by 0
fs/mbcache.c: make count_objects() more robust
Revert "mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical"
mm/madvise.c: fix madvise() infinite loop under special circumstances
exec: avoid RLIMIT_STACK races with prlimit()
IB/core: disable memory registration of filesystem-dax vmas
v4l2: disable filesystem-dax mapping support
mm: fail get_vaddr_frames() for filesystem-dax mappings
mm: introduce get_user_pages_longterm
device-dax: implement ->split() to catch invalid munmap attempts
mm, hugetlbfs: introduce ->split() to vm_operations_struct
scripts/faddr2line: extend usage on generic arch
...
I made a mistake during converting hugetlb code to 5-level paging: in
huge_pte_alloc() we have to use p4d_alloc(), not p4d_offset().
Otherwise it leads to crash -- NULL-pointer dereference in pud_alloc()
if p4d table is not yet allocated.
It only can happen in 5-level paging mode. In 4-level paging mode
p4d_offset() always returns pgd, so we are fine.
Link: http://lkml.kernel.org/r/20171122121921.64822-1-kirill.shutemov@linux.intel.com
Fixes: c2febafc67 ("mm: convert generic code to 5-level paging")
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org> [4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit d6810d7300 ("memcg, THP, swap: make mem_cgroup_swapout()
support THP") changed mem_cgroup_swapout() to support transparent huge
page (THP).
However the patch missed one location which should be changed for
correctly handling THPs. The resulting bug will cause the memory
cgroups whose THPs were swapped out to become zombies on deletion.
Link: http://lkml.kernel.org/r/20171128161941.20931-1-shakeelb@google.com
Fixes: d6810d7300 ("memcg, THP, swap: make mem_cgroup_swapout() support THP")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Greg Thelen <gthelen@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>
kmemleak_scan() will scan struct page for each node and it can be really
large and resulting in a soft lockup. We have seen a soft lockup when
do scan while compile kernel:
watchdog: BUG: soft lockup - CPU#53 stuck for 22s! [bash:10287]
[...]
Call Trace:
kmemleak_scan+0x21a/0x4c0
kmemleak_write+0x312/0x350
full_proxy_write+0x5a/0xa0
__vfs_write+0x33/0x150
vfs_write+0xad/0x1a0
SyS_write+0x52/0xc0
do_syscall_64+0x61/0x1a0
entry_SYSCALL64_slow_path+0x25/0x25
Fix this by adding cond_resched every MAX_SCAN_SIZE.
Link: http://lkml.kernel.org/r/1511439788-20099-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 0f6d24f878 ("mm/page-writeback.c: print a warning
if the vm dirtiness settings are illogical") because it causes false
positive warnings during OOM situations as noticed by Tetsuo Handa:
Node 0 active_anon:3525940kB inactive_anon:8372kB active_file:216kB inactive_file:1872kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:2504kB dirty:52kB writeback:0kB shmem:8660kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 636928kB writeback_tmp:0kB unstable:0kB all_unreclaimable? yes
Node 0 DMA free:14848kB min:284kB low:352kB high:420kB active_anon:992kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15988kB managed:15904kB mlocked:0kB kernel_stack:0kB pagetables:24kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
lowmem_reserve[]: 0 2687 3645 3645
Node 0 DMA32 free:53004kB min:49608kB low:62008kB high:74408kB active_anon:2712648kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:3129216kB managed:2773132kB mlocked:0kB kernel_stack:96kB pagetables:5096kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB
lowmem_reserve[]: 0 0 958 958
Node 0 Normal free:17140kB min:17684kB low:22104kB high:26524kB active_anon:812300kB inactive_anon:8372kB active_file:1228kB inactive_file:1868kB unevictable:0kB writepending:52kB present:1048576kB managed:981224kB mlocked:0kB kernel_stack:3520kB pagetables:8552kB bounce:0kB free_pcp:120kB local_pcp:120kB free_cma:0kB
lowmem_reserve[]: 0 0 0 0
[...]
Out of memory: Kill process 8459 (a.out) score 999 or sacrifice child
Killed process 8459 (a.out) total-vm:4180kB, anon-rss:88kB, file-rss:0kB, shmem-rss:0kB
oom_reaper: reaped process 8459 (a.out), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB
vm direct limit must be set greater than background limit.
The problem is that both thresh and bg_thresh will be 0 if
available_memory is less than 4 pages when evaluating
global_dirtyable_memory.
While this might be worked around the whole point of the warning is
dubious at best. We do rely on admins to do sensible things when
changing tunable knobs. Dirty memory writeback knobs are not any
special in that regards so revert the warning rather than adding more
hacks to work this around.
Debugged by Yafang Shao.
Link: http://lkml.kernel.org/r/20171127091939.tahb77nznytcxw55@dhcp22.suse.cz
Fixes: 0f6d24f878 ("mm/page-writeback.c: print a warning if the vm dirtiness settings are illogical")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
MADVISE_WILLNEED has always been a noop for DAX (formerly XIP) mappings.
Unfortunately madvise_willneed() doesn't communicate this information
properly to the generic madvise syscall implementation. The calling
convention is quite subtle there. madvise_vma() is supposed to either
return an error or update &prev otherwise the main loop will never
advance to the next vma and it will keep looping for ever without a way
to get out of the kernel.
It seems this has been broken since introduction. Nobody has noticed
because nobody seems to be using MADVISE_WILLNEED on these DAX mappings.
[mhocko@suse.com: rewrite changelog]
Link: http://lkml.kernel.org/r/20171127115318.911-1-guoxuenan@huawei.com
Fixes: fe77ba6f4f ("[PATCH] xip: madvice/fadvice: execute in place")
Signed-off-by: chenjie <chenjie6@huawei.com>
Signed-off-by: guoxuenan <guoxuenan@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: zhangyi (F) <yi.zhang@huawei.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Shaohua Li <shli@fb.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow V4L2, Exynos, and other frame vector users to create
long standing / irrevocable memory registrations against filesytem-dax
vmas.
[dan.j.williams@intel.com: add comment for vma_is_fsdax() check in get_vaddr_frames(), per Jan]
Link: http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a6 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
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 "introduce get_user_pages_longterm()", v2.
Here is a new get_user_pages api for cases where a driver intends to
keep an elevated page count indefinitely. This is distinct from usages
like iov_iter_get_pages where the elevated page counts are transient.
The iov_iter_get_pages cases immediately turn around and submit the
pages to a device driver which will put_page when the i/o operation
completes (under kernel control).
In the longterm case userspace is responsible for dropping the page
reference at some undefined point in the future. This is untenable for
filesystem-dax case where the filesystem is in control of the lifetime
of the block / page and needs reasonable limits on how long it can wait
for pages in a mapping to become idle.
Fixing filesystems to actually wait for dax pages to be idle before
blocks from a truncate/hole-punch operation are repurposed is saved for
a later patch series.
Also, allowing longterm registration of dax mappings is a future patch
series that introduces a "map with lease" semantic where the kernel can
revoke a lease and force userspace to drop its page references.
I have also tagged these for -stable to purposely break cases that might
assume that longterm memory registrations for filesystem-dax mappings
were supported by the kernel. The behavior regression this policy
change implies is one of the reasons we maintain the "dax enabled.
Warning: EXPERIMENTAL, use at your own risk" notification when mounting
a filesystem in dax mode.
It is worth noting the device-dax interface does not suffer the same
constraints since it does not support file space management operations
like hole-punch.
This patch (of 4):
Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow long standing memory registrations against
filesytem-dax vmas. Device-dax vmas do not have this problem and are
explicitly allowed.
This is temporary until a "memory registration with layout-lease"
mechanism can be implemented for the affected sub-systems (RDMA and
V4L2).
[akpm@linux-foundation.org: use kcalloc()]
Link: http://lkml.kernel.org/r/151068939435.7446.13560129395419350737.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a6 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Joonyoung Shim <jy0922.shim@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
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 "device-dax: fix unaligned munmap handling"
When device-dax is operating in huge-page mode we want it to behave like
hugetlbfs and fail attempts to split vmas into unaligned ranges. It
would be messy to teach the munmap path about device-dax alignment
constraints in the same (hstate) way that hugetlbfs communicates this
constraint. Instead, these patches introduce a new ->split() vm
operation.
This patch (of 2):
The device-dax interface has similar constraints as hugetlbfs in that it
requires the munmap path to unmap in huge page aligned units. Rather
than add more custom vma handling code in __split_vma() introduce a new
vm operation to perform this vma specific check.
Link: http://lkml.kernel.org/r/151130418135.4029.6783191281930729710.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: dee4107924 ("/dev/dax, core: file operations and dax-mmap")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Jeff Moyer <jmoyer@redhat.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 'access_permitted' helper is used in the gup-fast path and goes
beyond the simple _PAGE_RW check to also:
- validate that the mapping is writable from a protection keys
standpoint
- validate that the pte has _PAGE_USER set since all fault paths where
pte_write is must be referencing user-memory.
Link: http://lkml.kernel.org/r/151043111604.2842.8051684481794973100.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'access_permitted' helper is used in the gup-fast path and goes
beyond the simple _PAGE_RW check to also:
- validate that the mapping is writable from a protection keys
standpoint
- validate that the pte has _PAGE_USER set since all fault paths where
pmd_write is must be referencing user-memory.
Link: http://lkml.kernel.org/r/151043111049.2842.15241454964150083466.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The 'access_permitted' helper is used in the gup-fast path and goes
beyond the simple _PAGE_RW check to also:
- validate that the mapping is writable from a protection keys
standpoint
- validate that the pte has _PAGE_USER set since all fault paths where
pud_write is must be referencing user-memory.
[dan.j.williams@intel.com: fix powerpc compile error]
Link: http://lkml.kernel.org/r/151129127237.37405.16073414520854722485.stgit@dwillia2-desk3.amr.corp.intel.com
Link: http://lkml.kernel.org/r/151043110453.2842.2166049702068628177.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the call __alloc_contig_migrate_range() in alloc_contig_range returns
-EBUSY, processing continues so that test_pages_isolated() is called
where there is a tracepoint to identify the busy pages. However, it is
possible for busy pages to become available between the calls to these
two routines. In this case, the range of pages may be allocated.
Unfortunately, the original return code (ret == -EBUSY) is still set and
returned to the caller. Therefore, the caller believes the pages were
not allocated and they are leaked.
Update the comment to indicate that allocation is still possible even if
__alloc_contig_migrate_range returns -EBUSY. Also, clear return code in
this case so that it is not accidentally used or returned to caller.
Link: http://lkml.kernel.org/r/20171122185214.25285-1-mike.kravetz@oracle.com
Fixes: 8ef5849fa8 ("mm/cma: always check which page caused allocation failure")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tlb_gather_mmu(&tlb, mm, 0, -1) means gathering the whole virtual memory
space. In this case, tlb->fullmm is true. Some archs like arm64
doesn't flush TLB when tlb->fullmm is true:
commit 5a7862e830 ("arm64: tlbflush: avoid flushing when fullmm == 1").
Which causes leaking of tlb entries.
Will clarifies his patch:
"Basically, we tag each address space with an ASID (PCID on x86) which
is resident in the TLB. This means we can elide TLB invalidation when
pulling down a full mm because we won't ever assign that ASID to
another mm without doing TLB invalidation elsewhere (which actually
just nukes the whole TLB).
I think that means that we could potentially not fault on a kernel
uaccess, because we could hit in the TLB"
There could be a window between complete_signal() sending IPI to other
cores and all threads sharing this mm are really kicked off from cores.
In this window, the oom reaper may calls tlb_flush_mmu_tlbonly() to
flush TLB then frees pages. However, due to the above problem, the TLB
entries are not really flushed on arm64. Other threads are possible to
access these pages through TLB entries. Moreover, a copy_to_user() can
also write to these pages without generating page fault, causes
use-after-free bugs.
This patch gathers each vma instead of gathering full vm space. In this
case tlb->fullmm is not true. The behavior of oom reaper become similar
to munmapping before do_exit, which should be safe for all archs.
Link: http://lkml.kernel.org/r/20171107095453.179940-1-wangnan0@huawei.com
Fixes: aac4536355 ("mm, oom: introduce oom reaper")
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Bob Liu <liubo95@huawei.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drain_all_pages backs off when called from a kworker context since
commit 0ccce3b924 ("mm, page_alloc: drain per-cpu pages from workqueue
context") because the original IPI based pcp draining has been replaced
by a WQ based one and the check wanted to prevent from recursion and
inter workers dependencies. This has made some sense at the time
because the system WQ has been used and one worker holding the lock
could be blocked while waiting for new workers to emerge which can be a
problem under OOM conditions.
Since then commit ce612879dd ("mm: move pcp and lru-pcp draining into
single wq") has moved draining to a dedicated (mm_percpu_wq) WQ with a
rescuer so we shouldn't depend on any other WQ activity to make a
forward progress so calling drain_all_pages from a worker context is
safe as long as this doesn't happen from mm_percpu_wq itself which is
not the case because all workers are required to _not_ depend on any MM
locks.
Why is this a problem in the first place? ACPI driven memory hot-remove
(acpi_device_hotplug) is executed from the worker context. We end up
calling __offline_pages to free all the pages and that requires both
lru_add_drain_all_cpuslocked and drain_all_pages to do their job
otherwise we can have dangling pages on pcp lists and fail the offline
operation (__test_page_isolated_in_pageblock would see a page with 0 ref
count but without PageBuddy set).
Fix the issue by removing the worker check in drain_all_pages.
lru_add_drain_all_cpuslocked doesn't have this restriction so it works
as expected.
Link: http://lkml.kernel.org/r/20170828093341.26341-1-mhocko@kernel.org
Fixes: 0ccce3b924 ("mm, page_alloc: drain per-cpu pages from workqueue context")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org> [4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is the patch set that implements hashing of printk specifier
%p. First we have two clean up patches then we do the hashing. Hashing
is done via the SipHash algorithm. The next patch adds printk specifier
%px for printing pointers when we _really_ want to see the address i.e
%px is functionally equivalent to %lx. Final patch in the set fixes
KASAN since we break it by hashing %p.
For the record here is the justification for the series.
Currently there exist approximately 14 000 places in the Kernel where
addresses are being printed using an unadorned %p. This potentially
leaks sensitive information about the Kernel layout in memory. Many of
these calls are stale, instead of fixing every call we hash the address
by default before printing. We then add %px to provide a way to print
the actual address. Although this is achievable using %lx, using %px
will assist us if we ever want to change pointer printing behaviour. %px
is more uniquely grep'able (there are already >50 000 uses of %lx).
The added advantage of hashing %p is that security is now opt-out, if
you _really_ want the address you have to work a little harder and use
%px.
This will of course break some users, forcing code printing needed
addresses to be updated.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
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Merge tag 'printk-hash-pointer-4.15-rc2' of git://github.com/tcharding/linux
Pull printk pointer hashing update from Tobin Harding:
"Here is the patch set that implements hashing of printk specifier %p.
First we have two clean up patches then we do the hashing. Hashing is
done via the SipHash algorithm. The next patch adds printk specifier
%px for printing pointers when we _really_ want to see the address i.e
%px is functionally equivalent to %lx. Final patch in the set fixes
KASAN since we break it by hashing %p.
For the record here is the justification for the series:
Currently there exist approximately 14 000 places in the Kernel
where addresses are being printed using an unadorned %p. This
potentially leaks sensitive information about the Kernel layout in
memory. Many of these calls are stale, instead of fixing every call
we hash the address by default before printing. We then add %px to
provide a way to print the actual address. Although this is
achievable using %lx, using %px will assist us if we ever want to
change pointer printing behaviour. %px is more uniquely grep'able
(there are already >50 000 uses of %lx).
The added advantage of hashing %p is that security is now opt-out,
if you _really_ want the address you have to work a little harder
and use %px.
This will of course break some users, forcing code printing needed
addresses to be updated"
[ I do expect this to be an annoyance, and a number of %px users to be
added for debuggability. But nobody is willing to audit existing %p
users for information leaks, and a number of places really only use
the pointer as an object identifier rather than really 'I need the
address'.
IOW - sorry for the inconvenience, but it's the least inconvenient of
the options. - Linus ]
* tag 'printk-hash-pointer-4.15-rc2' of git://github.com/tcharding/linux:
kasan: use %px to print addresses instead of %p
vsprintf: add printk specifier %px
printk: hash addresses printed with %p
vsprintf: refactor %pK code out of pointer()
docs: correct documentation for %pK
This reverts commit 152e93af3c.
It was a nice cleanup in theory, but as Nicolai Stange points out, we do
need to make the page dirty for the copy-on-write case even when we
didn't end up making it writable, since the dirty bit is what we use to
check that we've gone through a COW cycle.
Reported-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pointers printed with %p are now hashed by default. Kasan needs the
actual address. We can use the new printk specifier %px for this
purpose.
Use %px instead of %p to print addresses.
Signed-off-by: Tobin C. Harding <me@tobin.cc>
Now that cond_resched() also provides RCU quiescent states when
needed, it can be used in place of cond_resched_rcu_qs(). This
commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
__poll_t is also used as wait key in some waitqueues.
Verify that wait_..._poll() gets __poll_t as key and
provide a helper for wakeup functions to get back to
that __poll_t value.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is a pure automated search-and-replace of the internal kernel
superblock flags.
The s_flags are now called SB_*, with the names and the values for the
moment mirroring the MS_* flags that they're equivalent to.
Note how the MS_xyz flags are the ones passed to the mount system call,
while the SB_xyz flags are what we then use in sb->s_flags.
The script to do this was:
# places to look in; re security/*: it generally should *not* be
# touched (that stuff parses mount(2) arguments directly), but
# there are two places where we really deal with superblock flags.
FILES="drivers/mtd drivers/staging/lustre fs ipc mm \
include/linux/fs.h include/uapi/linux/bfs_fs.h \
security/apparmor/apparmorfs.c security/apparmor/include/lib.h"
# the list of MS_... constants
SYMS="RDONLY NOSUID NODEV NOEXEC SYNCHRONOUS REMOUNT MANDLOCK \
DIRSYNC NOATIME NODIRATIME BIND MOVE REC VERBOSE SILENT \
POSIXACL UNBINDABLE PRIVATE SLAVE SHARED RELATIME KERNMOUNT \
I_VERSION STRICTATIME LAZYTIME SUBMOUNT NOREMOTELOCK NOSEC BORN \
ACTIVE NOUSER"
SED_PROG=
for i in $SYMS; do SED_PROG="$SED_PROG -e s/MS_$i/SB_$i/g"; done
# we want files that contain at least one of MS_...,
# with fs/namespace.c and fs/pnode.c excluded.
L=$(for i in $SYMS; do git grep -w -l MS_$i $FILES; done| sort|uniq|grep -v '^fs/namespace.c'|grep -v '^fs/pnode.c')
for f in $L; do sed -i $f $SED_PROG; done
Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 438a506180 ("percpu: don't forget to free the temporary struct
pcpu_alloc_info") uncovered a problem on the CRIS architecture where
the bootmem allocator is initialized with virtual addresses. Given it
has:
#define __va(x) ((void *)((unsigned long)(x) | 0x80000000))
then things just work out because the end result is the same whether you
give this a physical or a virtual address.
Untill you call memblock_free_early(__pa(address)) that is, because
values from __pa() don't match with the virtual addresses stuffed in the
bootmem allocator anymore.
Avoid freeing the temporary pcpu_alloc_info memory on that architecture
until they fix things up to let the kernel boot like it did before.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 438a506180 ("percpu: don't forget to free the temporary struct pcpu_alloc_info")
Currently we make page table entries dirty all the time regardless of
access type and don't even consider if the mapping is write-protected.
The reasoning is that we don't really need dirty tracking on THP and
making the entry dirty upfront may save some time on first write to the
page.
Unfortunately, such approach may result in false-positive
can_follow_write_pmd() for huge zero page or read-only shmem file.
Let's only make page dirty only if we about to write to the page anyway
(as we do for small pages).
I've restructured the code to make entry dirty inside
maybe_p[mu]d_mkwrite(). It also takes into account if the vma is
write-protected.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, we unconditionally make page table dirty in touch_pmd().
It may result in false-positive can_follow_write_pmd().
We may avoid the situation, if we would only make the page table entry
dirty if caller asks for write access -- FOLL_WRITE.
The patch also changes touch_pud() in the same way.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: linux-block@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Kees Cook <keescook@chromium.org>
In order to make error handle more cleaner we call bdi_debug_register
before set state to WB_registered, that we can avoid call bdi_unregister
in release_bdi().
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Convert bdi_debug_register to int and then do error handle for it.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Performance of get_user_pages_fast() is critical for some workloads, but
it's tricky to test it directly.
This patch provides /sys/kernel/debug/gup_benchmark that helps with
testing performance of it.
See tools/testing/selftests/vm/gup_benchmark.c for userspace
counterpart.
Link: http://lkml.kernel.org/r/20170908215603.9189-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Jonathan Corbet <corbet@lwn.net>
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>
Commit f3c931633a59 ("mm, compaction: persistently skip hugetlbfs
pageblocks") has introduced pageblock_skip_persistent() checks into
migration and free scanners, to make sure pageblocks that should be
persistently skipped are marked as such, regardless of the
ignore_skip_hint flag.
Since the previous patch introduced a new no_set_skip_hint flag, the
ignore flag no longer prevents marking pageblocks as skipped. Therefore
we can remove the special cases. The relevant pageblocks will be marked
as skipped by the common logic which marks each pageblock where no page
could be isolated. This makes the code simpler.
Link: http://lkml.kernel.org/r/20171102121706.21504-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
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>
Pageblock skip hints were added as a heuristic for compaction, which
shares core code with CMA. Since CMA reliability would suffer from the
heuristics, compact_control flag ignore_skip_hint was added for the CMA
use case. Since 6815bf3f23 ("mm/compaction: respect ignore_skip_hint
in update_pageblock_skip") the flag also means that CMA won't *update*
the skip hints in addition to ignoring them.
Today, direct compaction can also ignore the skip hints in the last
resort attempt, but there's no reason not to set them when isolation
fails in such case. Thus, this patch splits off a new no_set_skip_hint
flag to avoid the updating, which only CMA sets. This should improve
the heuristics a bit, and allow us to simplify the persistent skip bit
handling as the next step.
Link: http://lkml.kernel.org/r/20171102121706.21504-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
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>
pageblock_skip_persistent() checks for HugeTLB pages of pageblock order.
When clearing pageblock skip bits for compaction, the bits are not
cleared for such pageblocks, because they cannot contain base pages
suitable for migration, nor free pages to use as migration targets.
This optimization can be simply extended to all compound pages of order
equal or larger than pageblock order, because migrating such pages (if
they support it) cannot help sub-pageblock fragmentation. This includes
THP's and also gigantic HugeTLB pages, which the current implementation
doesn't persistently skip due to a strict pageblock_order equality check
and not recognizing tail pages.
While THP pages are generally less "persistent" than HugeTLB, we can
still expect that if a THP exists at the point of
__reset_isolation_suitable(), it will exist also during the subsequent
compaction run. The time difference here could be actually smaller than
between a compaction run that sets a (non-persistent) skip bit on a THP,
and the next compaction run that observes it.
Link: http://lkml.kernel.org/r/20171102121706.21504-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: 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>
It is pointless to migrate hugetlb memory as part of memory compaction
if the hugetlb size is equal to the pageblock order. No defragmentation
is occurring in this condition.
It is also pointless to for the freeing scanner to scan a pageblock
where a hugetlb page is pinned. Unconditionally skip these pageblocks,
and do so peristently so that they are not rescanned until it is
observed that these hugepages are no longer pinned.
It would also be possible to do this by involving the hugetlb subsystem
in marking pageblocks to no longer be skipped when they hugetlb pages
are freed. This is a simple solution that doesn't involve any
additional subsystems in pageblock skip manipulation.
[rientjes@google.com: fix build]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708201734390.117182@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151639130.106658@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Tested-by: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kcompactd is needlessly ignoring pageblock skip information. It is
doing MIGRATE_SYNC_LIGHT compaction, which is no more powerful than
MIGRATE_SYNC compaction.
If compaction recently failed to isolate memory from a set of
pageblocks, there is nothing to indicate that kcompactd will be able to
do so, or that it is beneficial from attempting to isolate memory.
Use the pageblock skip hint to avoid rescanning pageblocks needlessly
until that information is reset.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1708151638550.106658@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the following warning by removing the unused variable:
mm/shmem.c:3205:27: warning: variable 'info' set but not used [-Wunused-but-set-variable]
Link: http://lkml.kernel.org/r/1510774029-30652-1-git-send-email-clabbe@baylibre.com
Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
Acked-by: Michal Hocko <mhocko@suse.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>
There is a race in the current z3fold implementation between
do_compact() called in a work queue context and the page release
procedure when page's kref goes to 0.
do_compact() may be waiting for page lock, which is released by
release_z3fold_page_locked right before putting the page onto the
"stale" list, and then the page may be freed as do_compact() modifies
its contents.
The mechanism currently implemented to handle that (checking the
PAGE_STALE flag) is not reliable enough. Instead, we'll use page's kref
counter to guarantee that the page is not released if its compaction is
scheduled. It then becomes compaction function's responsibility to
decrease the counter and quit immediately if the page was actually
freed.
Link: http://lkml.kernel.org/r/20171117092032.00ea56f42affbed19f4fcc6c@gmail.com
Signed-off-by: Vitaly Wool <vitaly.wool@sonymobile.com>
Cc: <Oleksiy.Avramchenko@sony.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
'userspace flush' of persistent memory updates via filesystem-dax
mappings. It arranges for any filesystem metadata updates that may be
required to satisfy a write fault to also be flushed ("on disk") before
the kernel returns to userspace from the fault handler. Effectively
every write-fault that dirties metadata completes an fsync() before
returning from the fault handler. The new MAP_SHARED_VALIDATE mapping
type guarantees that the MAP_SYNC flag is validated as supported by the
filesystem's ->mmap() file operation.
* Add support for the standard ACPI 6.2 label access methods that
replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods. This
enables interoperability with environments that only implement the
standardized methods.
* Add support for the ACPI 6.2 NVDIMM media error injection methods.
* Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for latch
last shutdown status, firmware update, SMART error injection, and
SMART alarm threshold control.
* Cleanup physical address information disclosures to be root-only.
* Fix revalidation of the DIMM "locked label area" status to support
dynamic unlock of the label area.
* Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
(system-physical-address) command and error injection commands.
Acknowledgements that came after the commits were pushed to -next:
957ac8c421 dax: fix PMD faults on zero-length files
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
a39e596baa xfs: support for synchronous DAX faults
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
7b565c9f96 xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
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Merge tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm
Pull libnvdimm and dax updates from Dan Williams:
"Save for a few late fixes, all of these commits have shipped in -next
releases since before the merge window opened, and 0day has given a
build success notification.
The ext4 touches came from Jan, and the xfs touches have Darrick's
reviewed-by. An xfstest for the MAP_SYNC feature has been through
a few round of reviews and is on track to be merged.
- Introduce MAP_SYNC and MAP_SHARED_VALIDATE, a mechanism to enable
'userspace flush' of persistent memory updates via filesystem-dax
mappings. It arranges for any filesystem metadata updates that may
be required to satisfy a write fault to also be flushed ("on disk")
before the kernel returns to userspace from the fault handler.
Effectively every write-fault that dirties metadata completes an
fsync() before returning from the fault handler. The new
MAP_SHARED_VALIDATE mapping type guarantees that the MAP_SYNC flag
is validated as supported by the filesystem's ->mmap() file
operation.
- Add support for the standard ACPI 6.2 label access methods that
replace the NVDIMM_FAMILY_INTEL (vendor specific) label methods.
This enables interoperability with environments that only implement
the standardized methods.
- Add support for the ACPI 6.2 NVDIMM media error injection methods.
- Add support for the NVDIMM_FAMILY_INTEL v1.6 DIMM commands for
latch last shutdown status, firmware update, SMART error injection,
and SMART alarm threshold control.
- Cleanup physical address information disclosures to be root-only.
- Fix revalidation of the DIMM "locked label area" status to support
dynamic unlock of the label area.
- Expand unit test infrastructure to mock the ACPI 6.2 Translate SPA
(system-physical-address) command and error injection commands.
Acknowledgements that came after the commits were pushed to -next:
- 957ac8c421 ("dax: fix PMD faults on zero-length files"):
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
- a39e596baa ("xfs: support for synchronous DAX faults") and
7b565c9f96 ("xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()")
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>"
* tag 'libnvdimm-for-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (49 commits)
acpi, nfit: add 'Enable Latch System Shutdown Status' command support
dax: fix general protection fault in dax_alloc_inode
dax: fix PMD faults on zero-length files
dax: stop requiring a live device for dax_flush()
brd: remove dax support
dax: quiet bdev_dax_supported()
fs, dax: unify IOMAP_F_DIRTY read vs write handling policy in the dax core
tools/testing/nvdimm: unit test clear-error commands
acpi, nfit: validate commands against the device type
tools/testing/nvdimm: stricter bounds checking for error injection commands
xfs: support for synchronous DAX faults
xfs: Implement xfs_filemap_pfn_mkwrite() using __xfs_filemap_fault()
ext4: Support for synchronous DAX faults
ext4: Simplify error handling in ext4_dax_huge_fault()
dax: Implement dax_finish_sync_fault()
dax, iomap: Add support for synchronous faults
mm: Define MAP_SYNC and VM_SYNC flags
dax: Allow tuning whether dax_insert_mapping_entry() dirties entry
dax: Allow dax_iomap_fault() to return pfn
dax: Fix comment describing dax_iomap_fault()
...
Fixes in qemu, vhost and virtio.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:
"Fixes in qemu, vhost and virtio"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
fw_cfg: fix the command line module name
vhost/vsock: fix uninitialized vhost_vsock->guest_cid
vhost: fix end of range for access_ok
vhost/scsi: Use safe iteration in vhost_scsi_complete_cmd_work()
virtio_balloon: fix deadlock on OOM
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Merge tag 'afs-next-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull AFS updates from David Howells:
"kAFS filesystem driver overhaul.
The major points of the overhaul are:
(1) Preliminary groundwork is laid for supporting network-namespacing
of kAFS. The remainder of the namespacing work requires some way
to pass namespace information to submounts triggered by an
automount. This requires something like the mount overhaul that's
in progress.
(2) sockaddr_rxrpc is used in preference to in_addr for holding
addresses internally and add support for talking to the YFS VL
server. With this, kAFS can do everything over IPv6 as well as
IPv4 if it's talking to servers that support it.
(3) Callback handling is overhauled to be generally passive rather
than active. 'Callbacks' are promises by the server to tell us
about data and metadata changes. Callbacks are now checked when
we next touch an inode rather than actively going and looking for
it where possible.
(4) File access permit caching is overhauled to store the caching
information per-inode rather than per-directory, shared over
subordinate files. Whilst older AFS servers only allow ACLs on
directories (shared to the files in that directory), newer AFS
servers break that restriction.
To improve memory usage and to make it easier to do mass-key
removal, permit combinations are cached and shared.
(5) Cell database management is overhauled to allow lighter locks to
be used and to make cell records autonomous state machines that
look after getting their own DNS records and cleaning themselves
up, in particular preventing races in acquiring and relinquishing
the fscache token for the cell.
(6) Volume caching is overhauled. The afs_vlocation record is got rid
of to simplify things and the superblock is now keyed on the cell
and the numeric volume ID only. The volume record is tied to a
superblock and normal superblock management is used to mediate
the lifetime of the volume fscache token.
(7) File server record caching is overhauled to make server records
independent of cells and volumes. A server can be in multiple
cells (in such a case, the administrator must make sure that the
VL services for all cells correctly reflect the volumes shared
between those cells).
Server records are now indexed using the UUID of the server
rather than the address since a server can have multiple
addresses.
(8) File server rotation is overhauled to handle VMOVED, VBUSY (and
similar), VOFFLINE and VNOVOL indications and to handle rotation
both of servers and addresses of those servers. The rotation will
also wait and retry if the server says it is busy.
(9) Data writeback is overhauled. Each inode no longer stores a list
of modified sections tagged with the key that authorised it in
favour of noting the modified region of a page in page->private
and storing a list of keys that made modifications in the inode.
This simplifies things and allows other keys to be used to
actually write to the server if a key that made a modification
becomes useless.
(10) Writable mmap() is implemented. This allows a kernel to be build
entirely on AFS.
Note that Pre AFS-3.4 servers are no longer supported, though this can
be added back if necessary (AFS-3.4 was released in 1998)"
* tag 'afs-next-20171113' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (35 commits)
afs: Protect call->state changes against signals
afs: Trace page dirty/clean
afs: Implement shared-writeable mmap
afs: Get rid of the afs_writeback record
afs: Introduce a file-private data record
afs: Use a dynamic port if 7001 is in use
afs: Fix directory read/modify race
afs: Trace the sending of pages
afs: Trace the initiation and completion of client calls
afs: Fix documentation on # vs % prefix in mount source specification
afs: Fix total-length calculation for multiple-page send
afs: Only progress call state at end of Tx phase from rxrpc callback
afs: Make use of the YFS service upgrade to fully support IPv6
afs: Overhaul volume and server record caching and fileserver rotation
afs: Move server rotation code into its own file
afs: Add an address list concept
afs: Overhaul cell database management
afs: Overhaul permit caching
afs: Overhaul the callback handling
afs: Rename struct afs_call server member to cm_server
...
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Merge tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linux
Pull drm updates from Dave Airlie:
"This is the main drm pull request for v4.15.
Core:
- Atomic object lifetime fixes
- Atomic iterator improvements
- Sparse/smatch fixes
- Legacy kms ioctls to be interruptible
- EDID override improvements
- fb/gem helper cleanups
- Simple outreachy patches
- Documentation improvements
- Fix dma-buf rcu races
- DRM mode object leasing for improving VR use cases.
- vgaarb improvements for non-x86 platforms.
New driver:
- tve200: Faraday Technology TVE200 block.
This "TV Encoder" encodes a ITU-T BT.656 stream and can be found in
the StorLink SL3516 (later Cortina Systems CS3516) as well as the
Grain Media GM8180.
New bridges:
- SiI9234 support
New panels:
- S6E63J0X03, OTM8009A, Seiko 43WVF1G, 7" rpi touch panel, Toshiba
LT089AC19000, Innolux AT043TN24
i915:
- Remove Coffeelake from alpha support
- Cannonlake workarounds
- Infoframe refactoring for DisplayPort
- VBT updates
- DisplayPort vswing/emph/buffer translation refactoring
- CCS fixes
- Restore GPU clock boost on missed vblanks
- Scatter list updates for userptr allocations
- Gen9+ transition watermarks
- Display IPC (Isochronous Priority Control)
- Private PAT management
- GVT: improved error handling and pci config sanitizing
- Execlist refactoring
- Transparent Huge Page support
- User defined priorities support
- HuC/GuC firmware refactoring
- DP MST fixes
- eDP power sequencing fixes
- Use RCU instead of stop_machine
- PSR state tracking support
- Eviction fixes
- BDW DP aux channel timeout fixes
- LSPCON fixes
- Cannonlake PLL fixes
amdgpu:
- Per VM BO support
- Powerplay cleanups
- CI powerplay support
- PASID mgr for kfd
- SR-IOV fixes
- initial GPU reset for vega10
- Prime mmap support
- TTM updates
- Clock query interface for Raven
- Fence to handle ioctl
- UVD encode ring support on Polaris
- Transparent huge page DMA support
- Compute LRU pipe tweaks
- BO flag to allow buffers to opt out of implicit sync
- CTX priority setting API
- VRAM lost infrastructure plumbing
qxl:
- fix flicker since atomic rework
amdkfd:
- Further improvements from internal AMD tree
- Usermode events
- Drop radeon support
nouveau:
- Pascal temperature sensor support
- Improved BAR2 handling
- MMU rework to support Pascal MMU
exynos:
- Improved HDMI/mixer support
- HDMI audio interface support
tegra:
- Prep work for tegra186
- Cleanup/fixes
msm:
- Preemption support for a5xx
- Display fixes for 8x96 (snapdragon 820)
- Async cursor plane fixes
- FW loading rework
- GPU debugging improvements
vc4:
- Prep for DSI panels
- fix T-format tiling scanout
- New madvise ioctl
Rockchip:
- LVDS support
omapdrm:
- omap4 HDMI CEC support
etnaviv:
- GPU performance counters groundwork
sun4i:
- refactor driver load + TCON backend
- HDMI improvements
- A31 support
- Misc fixes
udl:
- Probe/EDID read fixes.
tilcdc:
- Misc fixes.
pl111:
- Support more variants
adv7511:
- Improve EDID handling.
- HDMI CEC support
sii8620:
- Add remote control support"
* tag 'drm-for-v4.15' of git://people.freedesktop.org/~airlied/linux: (1480 commits)
drm/rockchip: analogix_dp: Use mutex rather than spinlock
drm/mode_object: fix documentation for object lookups.
drm/i915: Reorder context-close to avoid calling i915_vma_close() under RCU
drm/i915: Move init_clock_gating() back to where it was
drm/i915: Prune the reservation shared fence array
drm/i915: Idle the GPU before shinking everything
drm/i915: Lock llist_del_first() vs llist_del_all()
drm/i915: Calculate ironlake intermediate watermarks correctly, v2.
drm/i915: Disable lazy PPGTT page table optimization for vGPU
drm/i915/execlists: Remove the priority "optimisation"
drm/i915: Filter out spurious execlists context-switch interrupts
drm/amdgpu: use irq-safe lock for kiq->ring_lock
drm/amdgpu: bypass lru touch for KIQ ring submission
drm/amdgpu: Potential uninitialized variable in amdgpu_vm_update_directories()
drm/amdgpu: potential uninitialized variable in amdgpu_vce_ring_parse_cs()
drm/amd/powerplay: initialize a variable before using it
drm/amd/powerplay: suppress KASAN out of bounds warning in vega10_populate_all_memory_levels
drm/amd/amdgpu: fix evicted VRAM bo adjudgement condition
drm/vblank: Tune drm_crtc_accurate_vblank_count() WARN down to a debug
drm/rockchip: add CONFIG_OF dependency for lvds
...
Merge updates from Andrew Morton:
- a few misc bits
- ocfs2 updates
- almost all of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (131 commits)
memory hotplug: fix comments when adding section
mm: make alloc_node_mem_map a void call if we don't have CONFIG_FLAT_NODE_MEM_MAP
mm: simplify nodemask printing
mm,oom_reaper: remove pointless kthread_run() error check
mm/page_ext.c: check if page_ext is not prepared
writeback: remove unused function parameter
mm: do not rely on preempt_count in print_vma_addr
mm, sparse: do not swamp log with huge vmemmap allocation failures
mm/hmm: remove redundant variable align_end
mm/list_lru.c: mark expected switch fall-through
mm/shmem.c: mark expected switch fall-through
mm/page_alloc.c: broken deferred calculation
mm: don't warn about allocations which stall for too long
fs: fuse: account fuse_inode slab memory as reclaimable
mm, page_alloc: fix potential false positive in __zone_watermark_ok
mm: mlock: remove lru_add_drain_all()
mm, sysctl: make NUMA stats configurable
shmem: convert shmem_init_inodecache() to void
Unify migrate_pages and move_pages access checks
mm, pagevec: rename pagevec drained field
...
Here, pfn_to_node should be page_to_nid.
Link: http://lkml.kernel.org/r/1510735205-22540-1-git-send-email-fan.du@intel.com
Signed-off-by: Fan Du <fan.du@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
free_area_init_node() calls alloc_node_mem_map(), but this function does
nothing unless we have CONFIG_FLAT_NODE_MEM_MAP.
As a cleanup, we can move the "#ifdef CONFIG_FLAT_NODE_MEM_MAP" within
alloc_node_mem_map() out of the function, and define a
alloc_node_mem_map() { } when CONFIG_FLAT_NODE_MEM_MAP is not present.
This also moves the printk that lays within the "#ifdef
CONFIG_FLAT_NODE_MEM_MAP" block from free_area_init_node() to
alloc_node_mem_map(), getting rid of the "#ifdef
CONFIG_FLAT_NODE_MEM_MAP" in free_area_init_node().
[akpm@linux-foundation.org: clean up the printk while we're there]
Link: http://lkml.kernel.org/r/20171114111935.GA11758@techadventures.net
Signed-off-by: Oscar Salvador <osalvador@techadventures.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_warn() and dump_header() have to explicitly handle NULL nodemask
which forces both paths to use pr_cont. We can do better. printk
already handles NULL pointers properly so all we need is to teach
nodemask_pr_args to handle NULL nodemask carefully. This allows
simplification of both alloc_warn() and dump_header() and gets rid of
pr_cont altogether.
This patch has been motivated by patch from Joe Perches
http://lkml.kernel.org/r/b31236dfe3fc924054fd7842bde678e71d193638.1509991345.git.joe@perches.com
[akpm@linux-foundation.org: fix tile warning, per Arnd]
Link: http://lkml.kernel.org/r/20171109100531.3cn2hcqnuj7mjaju@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since oom_init() is called before userspace processes start, memory
allocation failure for creating the OOM reaper kernel thread will let
the OOM killer call panic() rather than wake up the OOM reaper.
Link: http://lkml.kernel.org/r/1510137800-4602-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
online_page_ext() and page_ext_init() allocate page_ext for each
section, but they do not allocate if the first PFN is !pfn_present(pfn)
or !pfn_valid(pfn). Then section->page_ext remains as NULL.
lookup_page_ext checks NULL only if CONFIG_DEBUG_VM is enabled. For a
valid PFN, __set_page_owner will try to get page_ext through
lookup_page_ext. Without CONFIG_DEBUG_VM lookup_page_ext will misuse
NULL pointer as value 0. This incurrs invalid address access.
This is the panic example when PFN 0x100000 is not valid but PFN
0x13FC00 is being used for page_ext. section->page_ext is NULL,
get_entry returned invalid page_ext address as 0x1DFA000 for a PFN
0x13FC00.
To avoid this panic, CONFIG_DEBUG_VM should be removed so that page_ext
will be checked at all times.
Unable to handle kernel paging request at virtual address 01dfa014
------------[ cut here ]------------
Kernel BUG at ffffff80082371e0 [verbose debug info unavailable]
Internal error: Oops: 96000045 [#1] PREEMPT SMP
Modules linked in:
PC is at __set_page_owner+0x48/0x78
LR is at __set_page_owner+0x44/0x78
__set_page_owner+0x48/0x78
get_page_from_freelist+0x880/0x8e8
__alloc_pages_nodemask+0x14c/0xc48
__do_page_cache_readahead+0xdc/0x264
filemap_fault+0x2ac/0x550
ext4_filemap_fault+0x3c/0x58
__do_fault+0x80/0x120
handle_mm_fault+0x704/0xbb0
do_page_fault+0x2e8/0x394
do_mem_abort+0x88/0x124
Pre-4.7 kernels also need commit f86e427197 ("mm: check the return
value of lookup_page_ext for all call sites").
Link: http://lkml.kernel.org/r/20171107094131.14621-1-jaewon31.kim@samsung.com
Fixes: eefa864b70 ("mm/page_ext: resurrect struct page extending code for debugging")
Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: <stable@vger.kernel.org> [depends on f86e427197, see above]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The parameter `struct bdi_writeback *wb` is not been used in the
function body. Remove it.
Link: http://lkml.kernel.org/r/1509685485-15278-1-git-send-email-wanglong19@meituan.com
Signed-off-by: Wang Long <wanglong19@meituan.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The preempt count check on print_vma_addr has been added by commit
e8bff74afb ("x86: fix "BUG: sleeping function called from invalid
context" in print_vma_addr()") and it relied on the elevated preempt
count from preempt_conditional_sti because preempt_count check doesn't
work on non preemptive kernels by default.
The code has evolved though and commit d99e1bd175 ("x86/entry/traps:
Refactor preemption and interrupt flag handling") has replaced
preempt_conditional_sti by an explicit preempt_disable which is noop on
!PREEMPT so the check in print_vma_addr is broken.
Fix the issue by using trylock on mmap_sem rather than chacking the
preempt count. The allocation we are relying on has to be GFP_NOWAIT as
well. There is a chance that we won't dump the vma state if the lock is
contended or the memory short but this is acceptable outcome and much
less fragile than the not working preemption check or tricks around it.
Link: http://lkml.kernel.org/r/20171106134031.g6dbelg55mrbyc6i@dhcp22.suse.cz
Fixes: d99e1bd175 ("x86/entry/traps: Refactor preemption and interrupt flag handling")
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Yang Shi <yang.s@alibaba-inc.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While doing memory hotplug tests under heavy memory pressure we have
noticed too many page allocation failures when allocating vmemmap memmap
backed by huge page
kworker/u3072:1: page allocation failure: order:9, mode:0x24084c0(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO)
[...]
Call Trace:
dump_trace+0x59/0x310
show_stack_log_lvl+0xea/0x170
show_stack+0x21/0x40
dump_stack+0x5c/0x7c
warn_alloc_failed+0xe2/0x150
__alloc_pages_nodemask+0x3ed/0xb20
alloc_pages_current+0x7f/0x100
vmemmap_alloc_block+0x79/0xb6
__vmemmap_alloc_block_buf+0x136/0x145
vmemmap_populate+0xd2/0x2b9
sparse_mem_map_populate+0x23/0x30
sparse_add_one_section+0x68/0x18e
__add_pages+0x10a/0x1d0
arch_add_memory+0x4a/0xc0
add_memory_resource+0x89/0x160
add_memory+0x6d/0xd0
acpi_memory_device_add+0x181/0x251
acpi_bus_attach+0xfd/0x19b
acpi_bus_scan+0x59/0x69
acpi_device_hotplug+0xd2/0x41f
acpi_hotplug_work_fn+0x1a/0x23
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xbd/0xe0
ret_from_fork+0x3f/0x70
and we do see many of those because essentially every allocation fails
for each memory section. This is an excessive way to tell the user that
there is nothing to really worry about because we do have a fallback
mechanism to use base pages. The only downside might be a performance
degradation due to TLB pressure.
This patch changes vmemmap_alloc_block() to use __GFP_NOWARN and warn
explicitly once on the first allocation failure. This will reduce the
noise in the kernel log considerably, while we still have an indication
that a performance might be impacted.
[mhocko@kernel.org: forgot to git add the follow up fix]
Link: http://lkml.kernel.org/r/20171107090635.c27thtse2lchjgvb@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20171106092228.31098-1-mhocko@kernel.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variable align_end is assigned a value but it is never read, so the
variable is redundant and can be removed. Cleans up the clang warning:
Value stored to 'align_end' is never read
Link: http://lkml.kernel.org/r/20171017143837.23207-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Link: http://lkml.kernel.org/r/20171020190754.GA24332@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Link: http://lkml.kernel.org/r/20171020191058.GA24427@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In reset_deferred_meminit() we determine number of pages that must not
be deferred. We initialize pages for at least 2G of memory, but also
pages for reserved memory in this node.
The reserved memory is determined in this function:
memblock_reserved_memory_within(), which operates over physical
addresses, and returns size in bytes. However, reset_deferred_meminit()
assumes that that this function operates with pfns, and returns page
count.
The result is that in the best case machine boots slower than expected
due to initializing more pages than needed in single thread, and in the
worst case panics because fewer than needed pages are initialized early.
Link: http://lkml.kernel.org/r/20171021011707.15191-1-pasha.tatashin@oracle.com
Fixes: 864b9a393d ("mm: consider memblock reservations for deferred memory initialization sizing")
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 63f53dea0c ("mm: warn about allocations which stall for too
long") was a great step for reducing possibility of silent hang up
problem caused by memory allocation stalls. But this commit reverts it,
for it is possible to trigger OOM lockup and/or soft lockups when many
threads concurrently called warn_alloc() (in order to warn about memory
allocation stalls) due to current implementation of printk(), and it is
difficult to obtain useful information due to limitation of synchronous
warning approach.
Current printk() implementation flushes all pending logs using the
context of a thread which called console_unlock(). printk() should be
able to flush all pending logs eventually unless somebody continues
appending to printk() buffer.
Since warn_alloc() started appending to printk() buffer while waiting
for oom_kill_process() to make forward progress when oom_kill_process()
is processing pending logs, it became possible for warn_alloc() to force
oom_kill_process() loop inside printk(). As a result, warn_alloc()
significantly increased possibility of preventing oom_kill_process()
from making forward progress.
---------- Pseudo code start ----------
Before warn_alloc() was introduced:
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
}
goto retry;
After warn_alloc() was introduced:
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
} else if (waited_for_10seconds()) {
atomic_inc(&printk_pending_logs);
}
goto retry;
---------- Pseudo code end ----------
Although waited_for_10seconds() becomes true once per 10 seconds,
unbounded number of threads can call waited_for_10seconds() at the same
time. Also, since threads doing waited_for_10seconds() keep doing
almost busy loop, the thread doing print_one_log() can use little CPU
resource. Therefore, this situation can be simplified like
---------- Pseudo code start ----------
retry:
if (mutex_trylock(&oom_lock)) {
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_lock)
} else {
atomic_inc(&printk_pending_logs);
}
goto retry;
---------- Pseudo code end ----------
when printk() is called faster than print_one_log() can process a log.
One of possible mitigation would be to introduce a new lock in order to
make sure that no other series of printk() (either oom_kill_process() or
warn_alloc()) can append to printk() buffer when one series of printk()
(either oom_kill_process() or warn_alloc()) is already in progress.
Such serialization will also help obtaining kernel messages in readable
form.
---------- Pseudo code start ----------
retry:
if (mutex_trylock(&oom_lock)) {
mutex_lock(&oom_printk_lock);
while (atomic_read(&printk_pending_logs) > 0) {
atomic_dec(&printk_pending_logs);
print_one_log();
}
// Send SIGKILL here.
mutex_unlock(&oom_printk_lock);
mutex_unlock(&oom_lock)
} else {
if (mutex_trylock(&oom_printk_lock)) {
atomic_inc(&printk_pending_logs);
mutex_unlock(&oom_printk_lock);
}
}
goto retry;
---------- Pseudo code end ----------
But this commit does not go that direction, for we don't want to
introduce a new lock dependency, and we unlikely be able to obtain
useful information even if we serialized oom_kill_process() and
warn_alloc().
Synchronous approach is prone to unexpected results (e.g. too late [1],
too frequent [2], overlooked [3]). As far as I know, warn_alloc() never
helped with providing information other than "something is going wrong".
I want to consider asynchronous approach which can obtain information
during stalls with possibly relevant threads (e.g. the owner of
oom_lock and kswapd-like threads) and serve as a trigger for actions
(e.g. turn on/off tracepoints, ask libvirt daemon to take a memory dump
of stalling KVM guest for diagnostic purpose).
This commit temporarily loses ability to report e.g. OOM lockup due to
unable to invoke the OOM killer due to !__GFP_FS allocation request.
But asynchronous approach will be able to detect such situation and emit
warning. Thus, let's remove warn_alloc().
[1] https://bugzilla.kernel.org/show_bug.cgi?id=192981
[2] http://lkml.kernel.org/r/CAM_iQpWuPVGc2ky8M-9yukECtS+zKjiDasNymX7rMcBjBFyM_A@mail.gmail.com
[3] commit db73ee0d46 ("mm, vmscan: do not loop on too_many_isolated for ever"))
Link: http://lkml.kernel.org/r/1509017339-4802-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: Cong Wang <xiyou.wangcong@gmail.com>
Reported-by: yuwang.yuwang <yuwang.yuwang@alibaba-inc.com>
Reported-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit 97a16fc82a ("mm, page_alloc: only enforce watermarks for
order-0 allocations"), __zone_watermark_ok() check for high-order
allocations will shortcut per-migratetype free list checks for
ALLOC_HARDER allocations, and return true as long as there's free page
of any migratetype. The intention is that ALLOC_HARDER can allocate
from MIGRATE_HIGHATOMIC free lists, while normal allocations can't.
However, as a side effect, the watermark check will then also return
true when there are pages only on the MIGRATE_ISOLATE list, or (prior to
CMA conversion to ZONE_MOVABLE) on the MIGRATE_CMA list. Since the
allocation cannot actually obtain isolated pages, and might not be able
to obtain CMA pages, this can result in a false positive.
The condition should be rare and perhaps the outcome is not a fatal one.
Still, it's better if the watermark check is correct. There also
shouldn't be a performance tradeoff here.
Link: http://lkml.kernel.org/r/20171102125001.23708-1-vbabka@suse.cz
Fixes: 97a16fc82a ("mm, page_alloc: only enforce watermarks for order-0 allocations")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: David Rientjes <rientjes@google.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>
lru_add_drain_all() is not required by mlock() and it will drain
everything that has been cached at the time mlock is called. And that
is not really related to the memory which will be faulted in (and
cached) and mlocked by the syscall itself.
If anything lru_add_drain_all() should be called _after_ pages have been
mlocked and faulted in but even that is not strictly needed because
those pages would get to the appropriate LRUs lazily during the reclaim
path. Moreover follow_page_pte (gup) will drain the local pcp LRU
cache.
On larger machines the overhead of lru_add_drain_all() in mlock() can be
significant when mlocking data already in memory. We have observed high
latency in mlock() due to lru_add_drain_all() when the users were
mlocking in memory tmpfs files.
[mhocko@suse.com: changelog fix]
Link: http://lkml.kernel.org/r/20171019222507.2894-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the second step which introduces a tunable interface that allow
numa stats configurable for optimizing zone_statistics(), as suggested
by Dave Hansen and Ying Huang.
=========================================================================
When page allocation performance becomes a bottleneck and you can
tolerate some possible tool breakage and decreased numa counter
precision, you can do:
echo 0 > /proc/sys/vm/numa_stat
In this case, numa counter update is ignored. We can see about
*4.8%*(185->176) drop of cpu cycles per single page allocation and
reclaim on Jesper's page_bench01 (single thread) and *8.1%*(343->315)
drop of cpu cycles per single page allocation and reclaim on Jesper's
page_bench03 (88 threads) running on a 2-Socket Broadwell-based server
(88 threads, 126G memory).
Benchmark link provided by Jesper D Brouer (increase loop times to
10000000):
https://github.com/netoptimizer/prototype-kernel/tree/master/kernel/mm/bench
=========================================================================
When page allocation performance is not a bottleneck and you want all
tooling to work, you can do:
echo 1 > /proc/sys/vm/numa_stat
This is system default setting.
Many thanks to Michal Hocko, Dave Hansen, Ying Huang and Vlastimil Babka
for comments to help improve the original patch.
[keescook@chromium.org: make sure mutex is a global static]
Link: http://lkml.kernel.org/r/20171107213809.GA4314@beast
Link: http://lkml.kernel.org/r/1508290927-8518-1-git-send-email-kemi.wang@intel.com
Signed-off-by: Kemi Wang <kemi.wang@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Suggested-by: Ying Huang <ying.huang@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "Luis R . Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christopher Lameter <cl@linux.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
shmem_inode_cachep was created with SLAB_PANIC flag and
shmem_init_inodecache() never returns non-zero, so convert this
function to return void.
Link: http://lkml.kernel.org/r/20170909124542.GA35224@bogon.didichuxing.com
Signed-off-by: weiping zhang <zhangweiping@didichuxing.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>
Commit 197e7e5213 ("Sanitize 'move_pages()' permission checks") fixed
a security issue I reported in the move_pages syscall, and made it so
that you can't act on set-uid processes unless you have the
CAP_SYS_PTRACE capability.
Unify the access check logic of migrate_pages to match the new behavior
of move_pages. We discussed this a bit in the security@ list and
thought it'd be good for consistency even though there's no evident
security impact. The NUMA node access checks are left intact and
require CAP_SYS_NICE as before.
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1710011830320.6333@lakka.kapsi.fi
Signed-off-by: Otto Ebeling <otto.ebeling@iki.fi>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to Vlastimil Babka, the drained field in pagevec is
potentially misleading because it might be interpreted as draining this
pagevec instead of the percpu lru pagevecs. Rename the field for
clarity.
Link: http://lkml.kernel.org/r/20171019093346.ylahzdpzmoriyf4v@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rmqueue_bulk() fills an empty pcplist with pages from the free list. It
tries to preserve increasing order by pfn to the caller, because it
leads to better performance with some I/O controllers, as explained in
commit e084b2d95e ("page-allocator: preserve PFN ordering when
__GFP_COLD is set").
To preserve the order, it's sufficient to add pages to the tail of the
list as they are retrieved. The current code instead adds to the head
of the list, but then updates the list head pointer to the last added
page, in each step. This does result in the same order, but is
needlessly confusing and potentially wasteful, with no apparent benefit.
This patch simplifies the code and adjusts comment accordingly.
Link: http://lkml.kernel.org/r/f6505442-98a9-12e4-b2cd-0fa83874c159@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As the page free path makes no distinction between cache hot and cold
pages, there is no real useful ordering of pages in the free list that
allocation requests can take advantage of. Juding from the users of
__GFP_COLD, it is likely that a number of them are the result of copying
other sites instead of actually measuring the impact. Remove the
__GFP_COLD parameter which simplifies a number of paths in the page
allocator.
This is potentially controversial but bear in mind that the size of the
per-cpu pagelists versus modern cache sizes means that the whole per-cpu
list can often fit in the L3 cache. Hence, there is only a potential
benefit for microbenchmarks that alloc/free pages in a tight loop. It's
even worse when THP is taken into account which has little or no chance
of getting a cache-hot page as the per-cpu list is bypassed and the
zeroing of multiple pages will thrash the cache anyway.
The truncate microbenchmarks are not shown as this patch affects the
allocation path and not the free path. A page fault microbenchmark was
tested but it showed no sigificant difference which is not surprising
given that the __GFP_COLD branches are a miniscule percentage of the
fault path.
Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most callers users of free_hot_cold_page claim the pages being released
are cache hot. The exception is the page reclaim paths where it is
likely that enough pages will be freed in the near future that the
per-cpu lists are going to be recycled and the cache hotness information
is lost. As no one really cares about the hotness of pages being
released to the allocator, just ditch the parameter.
The APIs are renamed to indicate that it's no longer about hot/cold
pages. It should also be less confusing as there are subtle differences
between them. __free_pages drops a reference and frees a page when the
refcount reaches zero. free_hot_cold_page handled pages whose refcount
was already zero which is non-obvious from the name. free_unref_page
should be more obvious.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
[mgorman@techsingularity.net: add pages to head, not tail]
Link: http://lkml.kernel.org/r/20171019154321.qtpzaeftoyyw4iey@techsingularity.net
Link: http://lkml.kernel.org/r/20171018075952.10627-8-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All callers of release_pages claim the pages being released are cache
hot. As no one cares about the hotness of pages being released to the
allocator, just ditch the parameter.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
Link: http://lkml.kernel.org/r/20171018075952.10627-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Every pagevec_init user claims the pages being released are hot even in
cases where it is unlikely the pages are hot. As no one cares about the
hotness of pages being released to the allocator, just ditch the
parameter.
No performance impact is expected as the overhead is marginal. The
parameter is removed simply because it is a bit stupid to have a useless
parameter copied everywhere.
Link: http://lkml.kernel.org/r/20171018075952.10627-6-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a pagevec is initialised on the stack, it is generally used
multiple times over a range of pages, looking up entries and then
releasing them. On each pagevec_release, the per-cpu deferred LRU
pagevecs are drained on the grounds the page being released may be on
those queues and the pages may be cache hot. In many cases only the
first drain is necessary as it's unlikely that the range of pages being
walked is racing against LRU addition. Even if there is such a race,
the impact is marginal where as constantly redraining the lru pagevecs
costs.
This patch ensures that pagevec is only drained once in a given
lifecycle without increasing the cache footprint of the pagevec
structure. Only sparsetruncate tiny is shown here as large files have
many exceptional entries and calls pagecache_release less frequently.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
batchshadow-v1r1 onedrain-v1r1
Min Time 141.00 ( 0.00%) 141.00 ( 0.00%)
1st-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%)
Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%)
Max-95% Time 146.00 ( 0.00%) 145.00 ( 0.68%)
Max-99% Time 198.00 ( 0.00%) 194.00 ( 2.02%)
Max Time 254.00 ( 0.00%) 208.00 ( 18.11%)
Amean Time 145.12 ( 0.00%) 144.30 ( 0.56%)
Stddev Time 12.74 ( 0.00%) 9.62 ( 24.49%)
Coeff Time 8.78 ( 0.00%) 6.67 ( 24.06%)
Best99%Amean Time 144.29 ( 0.00%) 143.82 ( 0.32%)
Best95%Amean Time 142.68 ( 0.00%) 142.31 ( 0.26%)
Best90%Amean Time 142.52 ( 0.00%) 142.19 ( 0.24%)
Best75%Amean Time 142.26 ( 0.00%) 141.98 ( 0.20%)
Best50%Amean Time 141.90 ( 0.00%) 141.71 ( 0.13%)
Best25%Amean Time 141.80 ( 0.00%) 141.43 ( 0.26%)
The impact on bonnie is marginal and within the noise because a
significant percentage of the file being truncated has been reclaimed
and consists of shadow entries which reduce the hotness of the
pagevec_release path.
Link: http://lkml.kernel.org/r/20171018075952.10627-5-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.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>
During truncate each entry in a pagevec is checked to see if it is an
exceptional entry and if so, the shadow entry is cleaned up. This is
potentially expensive as multiple entries for a mapping locks/unlocks
the tree lock. This batches the operation such that any exceptional
entries removed from a pagevec only acquire the mapping tree lock once.
The corner case where this is more expensive is where there is only one
exceptional entry but this is unlikely due to temporal locality and how
it affects LRU ordering. Note that for truncations of small files
created recently, this patch should show no gain because it only batches
the handling of exceptional entries.
sparsetruncate (large)
4.14.0-rc4 4.14.0-rc4
pickhelper-v1r1 batchshadow-v1r1
Min Time 38.00 ( 0.00%) 27.00 ( 28.95%)
1st-qrtle Time 40.00 ( 0.00%) 28.00 ( 30.00%)
2nd-qrtle Time 44.00 ( 0.00%) 41.00 ( 6.82%)
3rd-qrtle Time 146.00 ( 0.00%) 147.00 ( -0.68%)
Max-90% Time 153.00 ( 0.00%) 153.00 ( 0.00%)
Max-95% Time 155.00 ( 0.00%) 156.00 ( -0.65%)
Max-99% Time 181.00 ( 0.00%) 171.00 ( 5.52%)
Amean Time 93.04 ( 0.00%) 88.43 ( 4.96%)
Best99%Amean Time 92.08 ( 0.00%) 86.13 ( 6.46%)
Best95%Amean Time 89.19 ( 0.00%) 83.13 ( 6.80%)
Best90%Amean Time 85.60 ( 0.00%) 79.15 ( 7.53%)
Best75%Amean Time 72.95 ( 0.00%) 65.09 ( 10.78%)
Best50%Amean Time 39.86 ( 0.00%) 28.20 ( 29.25%)
Best25%Amean Time 39.44 ( 0.00%) 27.70 ( 29.77%)
bonnie
4.14.0-rc4 4.14.0-rc4
pickhelper-v1r1 batchshadow-v1r1
Hmean SeqCreate ops 71.92 ( 0.00%) 76.78 ( 6.76%)
Hmean SeqCreate read 42.42 ( 0.00%) 45.01 ( 6.10%)
Hmean SeqCreate del 26519.88 ( 0.00%) 27191.87 ( 2.53%)
Hmean RandCreate ops 71.92 ( 0.00%) 76.95 ( 7.00%)
Hmean RandCreate read 44.44 ( 0.00%) 49.23 ( 10.78%)
Hmean RandCreate del 24948.62 ( 0.00%) 24764.97 ( -0.74%)
Truncation of a large number of files shows a substantial gain with 99%
of files being truncated 6.46% faster. bonnie shows a modest gain of
2.53%
[jack@suse.cz: fix truncate_exceptional_pvec_entries()]
Link: http://lkml.kernel.org/r/20171108164226.26788-1-jack@suse.cz
Link: http://lkml.kernel.org/r/20171018075952.10627-4-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
During truncation, the mapping has already been checked for shmem and
dax so it's known that workingset_update_node is required.
This patch avoids the checks on mapping for each page being truncated.
In all other cases, a lookup helper is used to determine if
workingset_update_node() needs to be called. The one danger is that the
API is slightly harder to use as calling workingset_update_node directly
without checking for dax or shmem mappings could lead to surprises.
However, the API rarely needs to be used and hopefully the comment is
enough to give people the hint.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
oneirq-v1r1 pickhelper-v1r1
Min Time 141.00 ( 0.00%) 140.00 ( 0.71%)
1st-qrtle Time 142.00 ( 0.00%) 141.00 ( 0.70%)
2nd-qrtle Time 142.00 ( 0.00%) 142.00 ( 0.00%)
3rd-qrtle Time 143.00 ( 0.00%) 143.00 ( 0.00%)
Max-90% Time 144.00 ( 0.00%) 144.00 ( 0.00%)
Max-95% Time 147.00 ( 0.00%) 145.00 ( 1.36%)
Max-99% Time 195.00 ( 0.00%) 191.00 ( 2.05%)
Max Time 230.00 ( 0.00%) 205.00 ( 10.87%)
Amean Time 144.37 ( 0.00%) 143.82 ( 0.38%)
Stddev Time 10.44 ( 0.00%) 9.00 ( 13.74%)
Coeff Time 7.23 ( 0.00%) 6.26 ( 13.41%)
Best99%Amean Time 143.72 ( 0.00%) 143.34 ( 0.26%)
Best95%Amean Time 142.37 ( 0.00%) 142.00 ( 0.26%)
Best90%Amean Time 142.19 ( 0.00%) 141.85 ( 0.24%)
Best75%Amean Time 141.92 ( 0.00%) 141.58 ( 0.24%)
Best50%Amean Time 141.69 ( 0.00%) 141.31 ( 0.27%)
Best25%Amean Time 141.38 ( 0.00%) 140.97 ( 0.29%)
As you'd expect, the gain is marginal but it can be detected. The
differences in bonnie are all within the noise which is not surprising
given the impact on the microbenchmark.
radix_tree_update_node_t is a callback for some radix operations that
optionally passes in a private field. The only user of the callback is
workingset_update_node and as it no longer requires a mapping, the
private field is removed.
Link: http://lkml.kernel.org/r/20171018075952.10627-3-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Patch series "Follow-up for speed up page cache truncation", v2.
This series is a follow-on for Jan Kara's series "Speed up page cache
truncation" series. We both ended up looking at the same problem but
saw different problems based on the same data. This series builds upon
his work.
A variety of workloads were compared on four separate machines but each
machine showed gains albeit at different levels. Minimally, some of the
differences are due to NUMA where truncating data from a remote node is
slower than a local node. The workloads checked were
o sparse truncate microbenchmark, tiny
o sparse truncate microbenchmark, large
o reaim-io disk workfile
o dbench4 (modified by mmtests to produce more stable results)
o filebench varmail configuration for small memory size
o bonnie, directory operations, working set size 2*RAM
reaim-io, dbench and filebench all showed minor gains. Truncation does
not dominate those workloads but were tested to ensure no other
regressions. They will not be reported further.
The sparse truncate microbench was written by Jan. It creates a number
of files and then times how long it takes to truncate each one. The
"tiny" configuraiton creates a number of files that easily fits in
memory and times how long it takes to truncate files with page cache.
The large configuration uses enough files to have data that is twice the
size of memory and so timings there include truncating page cache and
working set shadow entries in the radix tree.
Patches 1-4 are the most relevant parts of this series. Patches 5-8 are
optional as they are deleting code that is essentially useless but has a
negligible performance impact.
The changelogs have more information on performance but just for bonnie
delete options, the main comparison is
bonnie
4.14.0-rc5 4.14.0-rc5 4.14.0-rc5
jan-v2 vanilla mel-v2
Hmean SeqCreate ops 76.20 ( 0.00%) 75.80 ( -0.53%) 76.80 ( 0.79%)
Hmean SeqCreate read 85.00 ( 0.00%) 85.00 ( 0.00%) 85.00 ( 0.00%)
Hmean SeqCreate del 13752.31 ( 0.00%) 12090.23 ( -12.09%) 15304.84 ( 11.29%)
Hmean RandCreate ops 76.00 ( 0.00%) 75.60 ( -0.53%) 77.00 ( 1.32%)
Hmean RandCreate read 96.80 ( 0.00%) 96.80 ( 0.00%) 97.00 ( 0.21%)
Hmean RandCreate del 13233.75 ( 0.00%) 11525.35 ( -12.91%) 14446.61 ( 9.16%)
Jan's series is the baseline and the vanilla kernel is 12% slower where
as this series on top gains another 11%. This is from a different
machine than the data in the changelogs but the detailed data was not
collected as there was no substantial change in v2.
This patch (of 8):
Freeing a list of pages current enables/disables IRQs for each page
freed. This patch splits freeing a list of pages into two operations --
preparing the pages for freeing and the actual freeing. This is a
tradeoff - we're taking two passes of the list to free in exchange for
avoiding multiple enable/disable of IRQs.
sparsetruncate (tiny)
4.14.0-rc4 4.14.0-rc4
janbatch-v1r1 oneirq-v1r1
Min Time 149.00 ( 0.00%) 141.00 ( 5.37%)
1st-qrtle Time 150.00 ( 0.00%) 142.00 ( 5.33%)
2nd-qrtle Time 151.00 ( 0.00%) 142.00 ( 5.96%)
3rd-qrtle Time 151.00 ( 0.00%) 143.00 ( 5.30%)
Max-90% Time 153.00 ( 0.00%) 144.00 ( 5.88%)
Max-95% Time 155.00 ( 0.00%) 147.00 ( 5.16%)
Max-99% Time 201.00 ( 0.00%) 195.00 ( 2.99%)
Max Time 236.00 ( 0.00%) 230.00 ( 2.54%)
Amean Time 152.65 ( 0.00%) 144.37 ( 5.43%)
Stddev Time 9.78 ( 0.00%) 10.44 ( -6.72%)
Coeff Time 6.41 ( 0.00%) 7.23 ( -12.84%)
Best99%Amean Time 152.07 ( 0.00%) 143.72 ( 5.50%)
Best95%Amean Time 150.75 ( 0.00%) 142.37 ( 5.56%)
Best90%Amean Time 150.59 ( 0.00%) 142.19 ( 5.58%)
Best75%Amean Time 150.36 ( 0.00%) 141.92 ( 5.61%)
Best50%Amean Time 150.04 ( 0.00%) 141.69 ( 5.56%)
Best25%Amean Time 149.85 ( 0.00%) 141.38 ( 5.65%)
With a tiny number of files, each file truncated has resident page cache
and it shows that time to truncate is roughtly 5-6% with some minor
jitter.
4.14.0-rc4 4.14.0-rc4
janbatch-v1r1 oneirq-v1r1
Hmean SeqCreate ops 65.27 ( 0.00%) 81.86 ( 25.43%)
Hmean SeqCreate read 39.48 ( 0.00%) 47.44 ( 20.16%)
Hmean SeqCreate del 24963.95 ( 0.00%) 26319.99 ( 5.43%)
Hmean RandCreate ops 65.47 ( 0.00%) 82.01 ( 25.26%)
Hmean RandCreate read 42.04 ( 0.00%) 51.75 ( 23.09%)
Hmean RandCreate del 23377.66 ( 0.00%) 23764.79 ( 1.66%)
As expected, there is a small gain for the delete operation.
[mgorman@techsingularity.net: use page_private and set_page_private helpers]
Link: http://lkml.kernel.org/r/20171018101547.mjycw7zreb66jzpa@techsingularity.net
Link: http://lkml.kernel.org/r/20171018075952.10627-2-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Kara <jack@suse.cz>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we remove pages from the radix tree one by one. To speed up
page cache truncation, lock several pages at once and free them in one
go. This allows us to batch radix tree operations in a more efficient
way and also save round-trips on mapping->tree_lock. As a result we
gain about 20% speed improvement in page cache truncation.
Data from a simple benchmark timing 10000 truncates of 1024 pages (on
ext4 on ramdisk but the filesystem is barely visible in the profiles).
The range shows 1% and 95% percentiles of the measured times:
4.14-rc2 4.14-rc2 + batched truncation
248-256 209-219
249-258 209-217
248-255 211-239
248-255 209-217
247-256 210-218
[jack@suse.cz: convert delete_from_page_cache_batch() to pagevec]
Link: http://lkml.kernel.org/r/20171018111648.13714-1-jack@suse.cz
[akpm@linux-foundation.org: move struct pagevec forward declaration to top-of-file]
Link: http://lkml.kernel.org/r/20171010151937.26984-8-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Move checks and accounting updates from __delete_from_page_cache() into
a separate function. We will reuse it when batching page cache
truncation operations.
Link: http://lkml.kernel.org/r/20171010151937.26984-7-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Clearing of page->mapping makes sense in page_cache_tree_delete() as
well and it will help us with batching things this way.
Link: http://lkml.kernel.org/r/20171010151937.26984-6-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Move updates of various counters before page_cache_tree_delete() call.
It will be easier to batch things this way and there is no difference
whether the counters get updated before or after removal from the radix
tree.
Link: http://lkml.kernel.org/r/20171010151937.26984-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Factor out page freeing from delete_from_page_cache() into a separate
function. We will need to call the same when batching pagecache
deletion operations.
invalidate_complete_page2() and replace_page_cache_page() might want to
call this function as well however they currently don't seem to handle
THPs so it's unnecessary for them to take the hit of checking whether a
page is THP or not.
Link: http://lkml.kernel.org/r/20171010151937.26984-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Move call of delete_from_page_cache() and page->mapping check out of
truncate_complete_page() into the single caller - truncate_inode_page().
Also move page_mapped() check into truncate_complete_page(). That way
it will be easier to batch operations.
Also rename truncate_complete_page() to truncate_cleanup_page().
Link: http://lkml.kernel.org/r/20171010151937.26984-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@intel.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>
Patch series "Speed up page cache truncation", v1.
When rebasing our enterprise distro to a newer kernel (from 4.4 to 4.12)
we have noticed a regression in bonnie++ benchmark when deleting files.
Eventually we have tracked this down to a fact that page cache
truncation got slower by about 10%. There were both gains and losses in
the above interval of kernels but we have been able to identify that
commit 83929372f6 ("filemap: prepare find and delete operations for
huge pages") caused about 10% regression on its own.
After some investigation it didn't seem easily possible to fix the
regression while maintaining the THP in page cache functionality so
we've decided to optimize the page cache truncation path instead to make
up for the change. This series is a result of that effort.
Patch 1 is an easy speedup of cancel_dirty_page(). Patches 2-6 refactor
page cache truncation code so that it is easier to batch radix tree
operations. Patch 7 implements batching of deletes from the radix tree
which more than makes up for the original regression.
This patch (of 7):
cancel_dirty_page() does quite some work even for clean pages (fetching
of mapping, locking of memcg, atomic bit op on page flags) so it
accounts for ~2.5% of cost of truncation of a clean page. That is not
much but still dumb for something we don't need at all. Check whether a
page is actually dirty and avoid any work if not.
Link: http://lkml.kernel.org/r/20171010151937.26984-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Chinner <david@fromorbit.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>
In preparation for unconditionally passing the struct timer_list pointer
to all timer callbacks, switch to using the new timer_setup() and
from_timer() to pass the timer pointer explicitly.
Link: http://lkml.kernel.org/r/20171016225913.GA99214@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On a failed attempt, we get the following entry: soft offline: 0x3c0000:
migration failed 1, type 17ffffc0008008 (uptodate|head)
Make this more specific to be straightforward and to follow other error
log formats in soft_offline_huge_page().
Link: http://lkml.kernel.org/r/20171016171757.GA3018@ubuntu-desk-vm
Signed-off-by: Laszlo Toth <laszlth@gmail.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__rmqueue(), __rmqueue_fallback(), __rmqueue_smallest() and
__rmqueue_cma_fallback() are all in page allocator's hot path and better
be finished as soon as possible. One way to make them faster is by making
them inline. But as Andrew Morton and Andi Kleen pointed out:
https://lkml.org/lkml/2017/10/10/1252https://lkml.org/lkml/2017/10/10/1279
To make sure they are inlined, we should use __always_inline for them.
With the will-it-scale/page_fault1/process benchmark, when using nr_cpu
processes to stress buddy, the results for will-it-scale.processes with
and without the patch are:
On a 2-sockets Intel-Skylake machine:
compiler base head
gcc-4.4.7 6496131 6911823 +6.4%
gcc-4.9.4 7225110 7731072 +7.0%
gcc-5.4.1 7054224 7688146 +9.0%
gcc-6.2.0 7059794 7651675 +8.4%
On a 4-sockets Intel-Skylake machine:
compiler base head
gcc-4.4.7 13162890 13508193 +2.6%
gcc-4.9.4 14997463 15484353 +3.2%
gcc-5.4.1 14708711 15449805 +5.0%
gcc-6.2.0 14574099 15349204 +5.3%
The above 4 compilers are used because I've done the tests through
Intel's Linux Kernel Performance(LKP) infrastructure and they are the
available compilers there.
The benefit being less on 4 sockets machine is due to the lock
contention there(perf-profile/native_queued_spin_lock_slowpath=81%) is
less severe than on the 2 sockets machine(85%).
What the benchmark does is: it forks nr_cpu processes and then each
process does the following:
1 mmap() 128M anonymous space;
2 writes to each page there to trigger actual page allocation;
3 munmap() it.
in a loop.
https://github.com/antonblanchard/will-it-scale/blob/master/tests/page_fault1.c
Binary size wise, I have locally built them with different compilers:
[aaron@aaronlu obj]$ size */*/mm/page_alloc.o
text data bss dec hex filename
37409 9904 8524 55837 da1d gcc-4.9.4/base/mm/page_alloc.o
38273 9904 8524 56701 dd7d gcc-4.9.4/head/mm/page_alloc.o
37465 9840 8428 55733 d9b5 gcc-5.5.0/base/mm/page_alloc.o
38169 9840 8428 56437 dc75 gcc-5.5.0/head/mm/page_alloc.o
37573 9840 8428 55841 da21 gcc-6.4.0/base/mm/page_alloc.o
38261 9840 8428 56529 dcd1 gcc-6.4.0/head/mm/page_alloc.o
36863 9840 8428 55131 d75b gcc-7.2.0/base/mm/page_alloc.o
37711 9840 8428 55979 daab gcc-7.2.0/head/mm/page_alloc.o
Text size increased about 800 bytes for mm/page_alloc.o.
[aaron@aaronlu obj]$ size */*/vmlinux
text data bss dec hex filename
10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/base/vmlinux
10342757 5903208 17723392 33969357 20654cd gcc-4.9.4/head/vmlinux
10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/base/vmlinux
10332448 5836608 17715200 33884256 2050860 gcc-5.5.0/head/vmlinux
10094546 5836696 17715200 33646442 201676a gcc-6.4.0/base/vmlinux
10094546 5836696 17715200 33646442 201676a gcc-6.4.0/head/vmlinux
10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/base/vmlinux
10018775 5828732 17715200 33562707 2002053 gcc-7.2.0/head/vmlinux
Text size for vmlinux has no change though, probably due to function
alignment.
Link: http://lkml.kernel.org/r/20171013063111.GA26032@intel.com
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Kemi Wang <kemi.wang@intel.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vmemmap_alloc_block() will no longer zero the block, so zero memory at
its call sites for everything except struct pages. Struct page memory
is zero'd by struct page initialization.
Replace allocators in sparse-vmemmap to use the non-zeroing version.
So, we will get the performance improvement by zeroing the memory in
parallel when struct pages are zeroed.
Add struct page zeroing as a part of initialization of other fields in
__init_single_page().
This single thread performance collected on: Intel(R) Xeon(R) CPU E7-8895
v3 @ 2.60GHz with 1T of memory (268400646 pages in 8 nodes):
BASE FIX
sparse_init 11.244671836s 0.007199623s
zone_sizes_init 4.879775891s 8.355182299s
--------------------------
Total 16.124447727s 8.362381922s
sparse_init is where memory for struct pages is zeroed, and the zeroing
part is moved later in this patch into __init_single_page(), which is
called from zone_sizes_init().
[akpm@linux-foundation.org: make vmemmap_alloc_block_zero() private to sparse-vmemmap.c]
Link: http://lkml.kernel.org/r/20171013173214.27300-10-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some memory is reserved but unavailable: not present in memblock.memory
(because not backed by physical pages), but present in memblock.reserved.
Such memory has backing struct pages, but they are not initialized by
going through __init_single_page().
In some cases these struct pages are accessed even if they do not
contain any data. One example is page_to_pfn() might access page->flags
if this is where section information is stored (CONFIG_SPARSEMEM,
SECTION_IN_PAGE_FLAGS).
One example of such memory: trim_low_memory_range() unconditionally
reserves from pfn 0, but e820__memblock_setup() might provide the
exiting memory from pfn 1 (i.e. KVM).
Since struct pages are zeroed in __init_single_page(), and not during
allocation time, we must zero such struct pages explicitly.
The patch involves adding a new memblock iterator:
for_each_resv_unavail_range(i, p_start, p_end)
Which iterates through reserved && !memory lists, and we zero struct pages
explicitly by calling mm_zero_struct_page().
===
Here is more detailed example of problem that this patch is addressing:
Run tested on qemu with the following arguments:
-enable-kvm -cpu kvm64 -m 512 -smp 2
This patch reports that there are 98 unavailable pages.
They are: pfn 0 and pfns in range [159, 255].
Note, trim_low_memory_range() reserves only pfns in range [0, 15], it does
not reserve [159, 255] ones.
e820__memblock_setup() reports linux that the following physical ranges are
available:
[1 , 158]
[256, 130783]
Notice, that exactly unavailable pfns are missing!
Now, lets check what we have in zone 0: [1, 131039]
pfn 0, is not part of the zone, but pfns [1, 158], are.
However, the bigger problem we have if we do not initialize these struct
pages is with memory hotplug. Because, that path operates at 2M
boundaries (section_nr). And checks if 2M range of pages is hot
removable. It starts with first pfn from zone, rounds it down to 2M
boundary (sturct pages are allocated at 2M boundaries when vmemmap is
created), and checks if that section is hot removable. In this case
start with pfn 1 and convert it down to pfn 0. Later pfn is converted
to struct page, and some fields are checked. Now, if we do not zero
struct pages, we get unpredictable results.
In fact when CONFIG_VM_DEBUG is enabled, and we explicitly set all
vmemmap memory to ones, the following panic is observed with kernel test
without this patch applied:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: is_pageblock_removable_nolock+0x35/0x90
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT
...
task: ffff88001f4e2900 task.stack: ffffc90000314000
RIP: 0010:is_pageblock_removable_nolock+0x35/0x90
Call Trace:
? is_mem_section_removable+0x5a/0xd0
show_mem_removable+0x6b/0xa0
dev_attr_show+0x1b/0x50
sysfs_kf_seq_show+0xa1/0x100
kernfs_seq_show+0x22/0x30
seq_read+0x1ac/0x3a0
kernfs_fop_read+0x36/0x190
? security_file_permission+0x90/0xb0
__vfs_read+0x16/0x30
vfs_read+0x81/0x130
SyS_read+0x44/0xa0
entry_SYSCALL_64_fastpath+0x1f/0xbd
Link: http://lkml.kernel.org/r/20171013173214.27300-7-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* A new variant of memblock_virt_alloc_* allocations:
memblock_virt_alloc_try_nid_raw()
- Does not zero the allocated memory
- Does not panic if request cannot be satisfied
* optimize early system hash allocations
Clients can call alloc_large_system_hash() with flag: HASH_ZERO to
specify that memory that was allocated for system hash needs to be
zeroed, otherwise the memory does not need to be zeroed, and client will
initialize it.
If memory does not need to be zero'd, call the new
memblock_virt_alloc_raw() interface, and thus improve the boot
performance.
* debug for raw alloctor
When CONFIG_DEBUG_VM is enabled, this patch sets all the memory that is
returned by memblock_virt_alloc_try_nid_raw() to ones to ensure that no
places excpect zeroed memory.
Link: http://lkml.kernel.org/r/20171013173214.27300-6-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "complete deferred page initialization", v12.
SMP machines can benefit from the DEFERRED_STRUCT_PAGE_INIT config
option, which defers initializing struct pages until all cpus have been
started so it can be done in parallel.
However, this feature is sub-optimal, because the deferred page
initialization code expects that the struct pages have already been
zeroed, and the zeroing is done early in boot with a single thread only.
Also, we access that memory and set flags before struct pages are
initialized. All of this is fixed in this patchset.
In this work we do the following:
- Never read access struct page until it was initialized
- Never set any fields in struct pages before they are initialized
- Zero struct page at the beginning of struct page initialization
==========================================================================
Performance improvements on x86 machine with 8 nodes:
Intel(R) Xeon(R) CPU E7-8895 v3 @ 2.60GHz and 1T of memory:
TIME SPEED UP
base no deferred: 95.796233s
fix no deferred: 79.978956s 19.77%
base deferred: 77.254713s
fix deferred: 55.050509s 40.34%
==========================================================================
SPARC M6 3600 MHz with 15T of memory
TIME SPEED UP
base no deferred: 358.335727s
fix no deferred: 302.320936s 18.52%
base deferred: 237.534603s
fix deferred: 182.103003s 30.44%
==========================================================================
Raw dmesg output with timestamps:
x86 base no deferred: https://hastebin.com/ofunepurit.scala
x86 base deferred: https://hastebin.com/ifazegeyas.scala
x86 fix no deferred: https://hastebin.com/pegocohevo.scala
x86 fix deferred: https://hastebin.com/ofupevikuk.scala
sparc base no deferred: https://hastebin.com/ibobeteken.go
sparc base deferred: https://hastebin.com/fariqimiyu.go
sparc fix no deferred: https://hastebin.com/muhegoheyi.go
sparc fix deferred: https://hastebin.com/xadinobutu.go
This patch (of 11):
deferred_init_memmap() is called when struct pages are initialized later
in boot by slave CPUs. This patch simplifies and optimizes this
function, and also fixes a couple issues (described below).
The main change is that now we are iterating through free memblock areas
instead of all configured memory. Thus, we do not have to check if the
struct page has already been initialized.
=====
In deferred_init_memmap() where all deferred struct pages are
initialized we have a check like this:
if (page->flags) {
VM_BUG_ON(page_zone(page) != zone);
goto free_range;
}
This way we are checking if the current deferred page has already been
initialized. It works, because memory for struct pages has been zeroed,
and the only way flags are not zero if it went through
__init_single_page() before. But, once we change the current behavior
and won't zero the memory in memblock allocator, we cannot trust
anything inside "struct page"es until they are initialized. This patch
fixes this.
The deferred_init_memmap() is re-written to loop through only free
memory ranges provided by memblock.
Note, this first issue is relevant only when the following change is
merged:
=====
This patch fixes another existing issue on systems that have holes in
zones i.e CONFIG_HOLES_IN_ZONE is defined.
In for_each_mem_pfn_range() we have code like this:
if (!pfn_valid_within(pfn)
goto free_range;
Note: 'page' is not set to NULL and is not incremented but 'pfn'
advances. Thus means if deferred struct pages are enabled on systems
with these kind of holes, linux would get memory corruptions. I have
fixed this issue by defining a new macro that performs all the necessary
operations when we free the current set of pages.
[pasha.tatashin@oracle.com: buddy page accessed before initialized]
Link: http://lkml.kernel.org/r/20171102170221.7401-2-pasha.tatashin@oracle.com
Link: http://lkml.kernel.org/r/20171013173214.27300-2-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Tested-by: Bob Picco <bob.picco@oracle.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These global variables are only set during initialization or rarely
change, so declare them as __read_mostly.
Link: http://lkml.kernel.org/r/1507802349-5554-1-git-send-email-changbin.du@intel.com
Signed-off-by: Changbin Du <changbin.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that kmemcheck is gone, we don't need the NOTRACK flags.
Link: http://lkml.kernel.org/r/20171007030159.22241-5-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert all allocations that used a NOTRACK flag to stop using it.
Link: http://lkml.kernel.org/r/20171007030159.22241-3-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "kmemcheck: kill kmemcheck", v2.
As discussed at LSF/MM, kill kmemcheck.
KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow). KASan is already upstream.
We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).
The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.
Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.
This patch (of 4):
Remove kmemcheck annotations, and calls to kmemcheck from the kernel.
[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Hansen <devtimhansen@gmail.com>
Cc: Vegard Nossum <vegardno@ifi.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Variable cend is set but never read, hence it is redundant and can be
removed.
Cleans up clang build warning: Value stored to 'cend' is never read
Link: http://lkml.kernel.org/r/20171011174942.1372-1-colin.king@canonical.com
Fixes: 369ea8242c ("mm/rmap: update to new mmu_notifier semantic v2")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: 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>
Currently, we account page tables separately for each page table level,
but that's redundant -- we only make use of total memory allocated to
page tables for oom_badness calculation. We also provide the
information to userspace, but it has dubious value there too.
This patch switches page table accounting to single counter.
mm->pgtables_bytes is now used to account all page table levels. We use
bytes, because page table size for different levels of page table tree
may be different.
The change has user-visible effect: we don't have VmPMD and VmPUD
reported in /proc/[pid]/status. Not sure if anybody uses them. (As
alternative, we can always report 0 kB for them.)
OOM-killer report is also slightly changed: we now report pgtables_bytes
instead of nr_ptes, nr_pmd, nr_puds.
Apart from reducing number of counters per-mm, the benefit is that we
now calculate oom_badness() more correctly for machines which have
different size of page tables depending on level or where page tables
are less than a page in size.
The only downside can be debuggability because we do not know which page
table level could leak. But I do not remember many bugs that would be
caught by separate counters so I wouldn't lose sleep over this.
[akpm@linux-foundation.org: fix mm/huge_memory.c]
Link: http://lkml.kernel.org/r/20171006100651.44742-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
[kirill.shutemov@linux.intel.com: fix build]
Link: http://lkml.kernel.org/r/20171016150113.ikfxy3e7zzfvsr4w@black.fi.intel.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's add wrappers for ->nr_ptes with the same interface as for nr_pmd
and nr_pud.
The patch also makes nr_ptes accounting dependent onto CONFIG_MMU. Page
table accounting doesn't make sense if you don't have page tables.
It's preparation for consolidation of page-table counters in mm_struct.
Link: http://lkml.kernel.org/r/20171006100651.44742-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On a machine with 5-level paging support a process can allocate
significant amount of memory and stay unnoticed by oom-killer and memory
cgroup. The trick is to allocate a lot of PUD page tables. We don't
account PUD page tables, only PMD and PTE.
We already addressed the same issue for PMD page tables, see commit
dc6c9a35b6 ("mm: account pmd page tables to the process").
Introduction of 5-level paging brings the same issue for PUD page
tables.
The patch expands accounting to PUD level.
[kirill.shutemov@linux.intel.com: s/pmd_t/pud_t/]
Link: http://lkml.kernel.org/r/20171004074305.x35eh5u7ybbt5kar@black.fi.intel.com
[heiko.carstens@de.ibm.com: s390/mm: fix pud table accounting]
Link: http://lkml.kernel.org/r/20171103090551.18231-1-heiko.carstens@de.ibm.com
Link: http://lkml.kernel.org/r/20171002080427.3320-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Rik van Riel <riel@redhat.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>
Kmemleak can be tweaked at runtime by writing commands into debugfs
file. Root can use it anyway, but without the write-bit this interface
isn't obvious.
Link: http://lkml.kernel.org/r/150728996582.744328.11541332857988399411.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All users of pagevec_lookup() and pagevec_lookup_range() now pass
PAGEVEC_SIZE as a desired number of pages. Just drop the argument.
Link: http://lkml.kernel.org/r/20171009151359.31984-15-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently pagevec_lookup_range_tag() takes number of pages to look up
but most users don't need this. Create a new function
pagevec_lookup_range_nr_tag() that takes maximum number of pages to
lookup for Ceph which wants this functionality so that we can drop
nr_pages argument from pagevec_lookup_range_tag().
Link: http://lkml.kernel.org/r/20171009151359.31984-13-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use pagevec_lookup_range_tag() in write_cache_pages() as it is
interested only in pages from given range. Remove unnecessary code
resulting from this.
Link: http://lkml.kernel.org/r/20171009151359.31984-12-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use pagevec_lookup_range_tag() in __filemap_fdatawait_range() as it is
interested only in pages from given range. Remove unnecessary code
resulting from this.
Link: http://lkml.kernel.org/r/20171009151359.31984-11-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Ranged pagevec tagged lookup", v3.
In this series I provide a ranged variant of pagevec_lookup_tag() and
use it in places where it makes sense. This series removes some common
code and it also has a potential for speeding up some operations
similarly as for pagevec_lookup_range() (but for now I can think of only
artificial cases where this happens).
This patch (of 16):
Implement a variant of find_get_pages_tag() that stops iterating at
given index. Lots of users of this function (through pagevec_lookup())
actually want a range lookup and all of them are currently open-coding
this.
Also create corresponding pagevec_lookup_range_tag() function.
Link: http://lkml.kernel.org/r/20171009151359.31984-2-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: David Howells <dhowells@redhat.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steve French <sfrench@samba.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Maximum page order can be at max 10 which can be accomodated in short
data type(2 bytes). last_migrate_reason is defined as enum type whose
values can be accomodated in short data type (2 bytes).
Total structure size is currently 16 bytes but after changing structure
size it goes to 12 bytes.
Vlastimil said:
"Looks like it works, so why not.
Before:
[ 0.001000] allocated 50331648 bytes of page_ext
After:
[ 0.001000] allocated 41943040 bytes of page_ext"
Link: http://lkml.kernel.org/r/1507623917-37991-1-git-send-email-ayush.m@samsung.com
Signed-off-by: Ayush Mittal <ayush.m@samsung.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It was observed that under cma_alloc fail log, pr_info was used instead
of pr_err. This will lead to problems if printk debug level is set to
below 7. In this case the cma_alloc failure log will not be captured in
the log and it will be difficult to debug.
Simply replace the pr_info with pr_err to capture failure log.
Link: http://lkml.kernel.org/r/1507650633-4430-1-git-send-email-pintu.ping@gmail.com
Signed-off-by: Pintu Agarwal <pintu.ping@gmail.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jaewon Kim <jaewon31.kim@samsung.com>
Cc: Doug Berger <opendmb@gmail.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>
Memory allocations can happen before the swap_slots cache initialization
is completed during cpu bring up. If we are low on memory, we could
call get_swap_page() and access swap_slots_cache before it is fully
initialized.
Add a check in get_swap_page() for initialized swap_slots_cache to
prevent this condition. Similar check already exists in free_swap_slot.
Also annotate the checks to indicate the likely condition.
We also added a memory barrier to make sure that the locks
initialization are done before the assignment of cache->slots and
cache->slots_ret pointers. This ensures the assumption that it is safe
to acquire the slots cache locks and use the slots cache when the
corresponding cache->slots or cache->slots_ret pointers are non null.
[akpm@linux-foundation.org: tidy up comment]
[akpm@linux-foundation.org: fix spello in comment]
Link: http://lkml.kernel.org/r/65a9d0f133f63e66bba37b53b2fd0464b7cae771.1500677066.git.tim.c.chen@linux.intel.com
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Reported-by: Wenwei Tao <wenwei.tww@alibaba-inc.com>
Acked-by: Ying Huang <ying.huang@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Hillf Danton <hdanton@sina.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>
Since commit 59dc76b0d4 ("mm: vmscan: reduce size of inactive file
list") 'pgdat->inactive_ratio' is not used, except for printing
"node_inactive_ratio: 0" in /proc/zoneinfo output.
Remove it.
Link: http://lkml.kernel.org/r/20171003152611.27483-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is an optimization patch that only affect mmu_notifier users which
rely on the invalidate_range() callback. This patch avoids calling that
callback twice in a row from inside __mmu_notifier_invalidate_range_end
Existing pattern (before this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_end()
mmu_notifier_invalidate_range()
New pattern (after this patch):
mmu_notifier_invalidate_range_start()
pte/pmd/pud_clear_flush_notify()
mmu_notifier_invalidate_range()
mmu_notifier_invalidate_range_only_end()
We call the invalidate_range callback after clearing the page table
under the page table lock and we skip the call to invalidate_range
inside the __mmu_notifier_invalidate_range_end() function.
Idea from Andrea Arcangeli
Link: http://lkml.kernel.org/r/20171017031003.7481-3-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch only affects users of mmu_notifier->invalidate_range callback
which are device drivers related to ATS/PASID, CAPI, IOMMUv2, SVM ...
and it is an optimization for those users. Everyone else is unaffected
by it.
When clearing a pte/pmd we are given a choice to notify the event under
the page table lock (notify version of *_clear_flush helpers do call the
mmu_notifier_invalidate_range). But that notification is not necessary
in all cases.
This patch removes almost all cases where it is useless to have a call
to mmu_notifier_invalidate_range before
mmu_notifier_invalidate_range_end. It also adds documentation in all
those cases explaining why.
Below is a more in depth analysis of why this is fine to do this:
For secondary TLB (non CPU TLB) like IOMMU TLB or device TLB (when
device use thing like ATS/PASID to get the IOMMU to walk the CPU page
table to access a process virtual address space). There is only 2 cases
when you need to notify those secondary TLB while holding page table
lock when clearing a pte/pmd:
A) page backing address is free before mmu_notifier_invalidate_range_end
B) a page table entry is updated to point to a new page (COW, write fault
on zero page, __replace_page(), ...)
Case A is obvious you do not want to take the risk for the device to write
to a page that might now be used by something completely different.
Case B is more subtle. For correctness it requires the following sequence
to happen:
- take page table lock
- clear page table entry and notify (pmd/pte_huge_clear_flush_notify())
- set page table entry to point to new page
If clearing the page table entry is not followed by a notify before setting
the new pte/pmd value then you can break memory model like C11 or C++11 for
the device.
Consider the following scenario (device use a feature similar to ATS/
PASID):
Two address addrA and addrB such that |addrA - addrB| >= PAGE_SIZE we
assume they are write protected for COW (other case of B apply too).
[Time N] -----------------------------------------------------------------
CPU-thread-0 {try to write to addrA}
CPU-thread-1 {try to write to addrB}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {read addrA and populate device TLB}
DEV-thread-2 {read addrB and populate device TLB}
[Time N+1] ---------------------------------------------------------------
CPU-thread-0 {COW_step0: {mmu_notifier_invalidate_range_start(addrA)}}
CPU-thread-1 {COW_step0: {mmu_notifier_invalidate_range_start(addrB)}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+2] ---------------------------------------------------------------
CPU-thread-0 {COW_step1: {update page table point to new page for addrA}}
CPU-thread-1 {COW_step1: {update page table point to new page for addrB}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {preempted}
CPU-thread-2 {write to addrA which is a write to new page}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+3] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {preempted}
CPU-thread-2 {}
CPU-thread-3 {write to addrB which is a write to new page}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+4] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {COW_step3: {mmu_notifier_invalidate_range_end(addrB)}}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {}
DEV-thread-2 {}
[Time N+5] ---------------------------------------------------------------
CPU-thread-0 {preempted}
CPU-thread-1 {}
CPU-thread-2 {}
CPU-thread-3 {}
DEV-thread-0 {read addrA from old page}
DEV-thread-2 {read addrB from new page}
So here because at time N+2 the clear page table entry was not pair with a
notification to invalidate the secondary TLB, the device see the new value
for addrB before seing the new value for addrA. This break total memory
ordering for the device.
When changing a pte to write protect or to point to a new write protected
page with same content (KSM) it is ok to delay invalidate_range callback
to mmu_notifier_invalidate_range_end() outside the page table lock. This
is true even if the thread doing page table update is preempted right
after releasing page table lock before calling
mmu_notifier_invalidate_range_end
Thanks to Andrea for thinking of a problematic scenario for COW.
[jglisse@redhat.com: v2]
Link: http://lkml.kernel.org/r/20171017031003.7481-2-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170901173011.10745-1-jglisse@redhat.com
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alistair Popple <alistair@popple.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use BUG_ON(in_interrupt()) in zs_map_object(). This is not a new
BUG_ON(), it's always been there, but was recently changed to
VM_BUG_ON(). There are several problems there. First, we use use
per-CPU mappings both in zsmalloc and in zram, and interrupt may easily
corrupt those buffers. Second, and more importantly, we believe it's
possible to start leaking sensitive information. Consider the following
case:
-> process P
swap out
zram
per-cpu mapping CPU1
compress page A
-> IRQ
swap out
zram
per-cpu mapping CPU1
compress page B
write page from per-cpu mapping CPU1 to zsmalloc pool
iret
-> process P
write page from per-cpu mapping CPU1 to zsmalloc pool [*]
return
* so we store overwritten data that actually belongs to another
page (task) and potentially contains sensitive data. And when
process P will page fault it's going to read (swap in) that
other task's data.
Link: http://lkml.kernel.org/r/20170929045140.4055-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
