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e0abfbb671
540 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Baoquan He
|
4b68a773a7 |
mm/vmalloc.c: optimize to reduce arguments of alloc_vmap_area()
If called by __get_vm_area_node(), by open coding the field assignments of 'struct vm_struct *vm', and move the vm->flags and vm->caller assignments into __get_vm_area_node(), the passed in arguments 'flags' and 'caller' can be removed. This alleviates overloaded arguments passed in for alloc_vmap_area(). Link: https://lkml.kernel.org/r/20240309044454.648888-1-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
rulinhuang
|
aaab830ad8 |
mm/vmalloc: eliminated the lock contention from twice to once
When allocating a new memory area where the mapping address range is known, it is observed that the vmap_node->busy.lock is acquired twice. The first acquisition occurs in the alloc_vmap_area() function when inserting the vm area into the vm mapping red-black tree. The second acquisition occurs in the setup_vmalloc_vm() function when updating the properties of the vm, such as flags and address, etc. Combine these two operations together in alloc_vmap_area(), which improves scalability when the vmap_node->busy.lock is contended. By doing so, the need to acquire the lock twice can also be eliminated to once. With the above change, tested on intel sapphire rapids platform(224 vcpu), a 4% performance improvement is gained on stress-ng/pthread(https://github.com/ColinIanKing/stress-ng), which is the stress test of thread creations. Link: https://lkml.kernel.org/r/20240307021440.64967-1-rulin.huang@intel.com Co-developed-by: "Chen, Tim C" <tim.c.chen@intel.com> Signed-off-by: "Chen, Tim C" <tim.c.chen@intel.com> Co-developed-by: "King, Colin" <colin.king@intel.com> Signed-off-by: "King, Colin" <colin.king@intel.com> Signed-off-by: rulinhuang <rulin.huang@intel.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Wangyang Guo <wangyang.guo@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Kent Overstreet
|
88ae5fb755 |
mm: vmalloc: enable memory allocation profiling
This wrapps all external vmalloc allocation functions with the alloc_hooks() wrapper, and switches internal allocations to _noprof variants where appropriate, for the new memory allocation profiling feature. [surenb@google.com: arch/um: fix forward declaration for vmalloc] Link: https://lkml.kernel.org/r/20240326073750.726636-1-surenb@google.com [surenb@google.com: undo _noprof additions in the documentation] Link: https://lkml.kernel.org/r/20240326231453.1206227-5-surenb@google.com Link: https://lkml.kernel.org/r/20240321163705.3067592-31-surenb@google.com Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> Signed-off-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Kees Cook <keescook@chromium.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Andreas Hindborg <a.hindborg@samsung.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Gary Guo <gary@garyguo.net> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Uladzislau Rezki (Sony)
|
fc2c22693c |
mm: vmalloc: fix lockdep warning
A lockdep reports a possible deadlock in the find_vmap_area_exceed_addr_lock()
function:
============================================
WARNING: possible recursive locking detected
6.9.0-rc1-00060-ged3ccc57b108-dirty #6140 Not tainted
--------------------------------------------
drgn/455 is trying to acquire lock:
ffff0000c00131d0 (&vn->busy.lock/1){+.+.}-{2:2}, at: find_vmap_area_exceed_addr_lock+0x64/0x124
but task is already holding lock:
ffff0000c0011878 (&vn->busy.lock/1){+.+.}-{2:2}, at: find_vmap_area_exceed_addr_lock+0x64/0x124
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&vn->busy.lock/1);
lock(&vn->busy.lock/1);
*** DEADLOCK ***
indeed it can happen if the find_vmap_area_exceed_addr_lock() gets called
concurrently because it tries to acquire two nodes locks. It was done to
prevent removing a lowest VA found on a previous step.
To address this a lowest VA is found first without holding a node lock
where it resides. As a last step we check if a VA still there because it
can go away, if removed, proceed with next lowest.
[akpm@linux-foundation.org: fix comment typos, per Baoquan]
Link: https://lkml.kernel.org/r/20240328140330.4747-1-urezki@gmail.com
Fixes:
|
||
|
Uladzislau Rezki (Sony)
|
4ed91fa917 |
mm: vmalloc: bail out early in find_vmap_area() if vmap is not init
During the boot the s390 system triggers "spinlock bad magic" messages
if the spinlock debugging is enabled:
[ 0.465445] BUG: spinlock bad magic on CPU#0, swapper/0
[ 0.465490] lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[ 0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1
[ 0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux)
[ 0.466270] Call Trace:
[ 0.466470] [<00000000011f26c8>] dump_stack_lvl+0x98/0xd8
[ 0.466516] [<00000000001dcc6a>] do_raw_spin_lock+0x8a/0x108
[ 0.466545] [<000000000042146c>] find_vmap_area+0x6c/0x108
[ 0.466572] [<000000000042175a>] find_vm_area+0x22/0x40
[ 0.466597] [<000000000012f152>] __set_memory+0x132/0x150
[ 0.466624] [<0000000001cc0398>] vmem_map_init+0x40/0x118
[ 0.466651] [<0000000001cc0092>] paging_init+0x22/0x68
[ 0.466677] [<0000000001cbbed2>] setup_arch+0x52a/0x708
[ 0.466702] [<0000000001cb6140>] start_kernel+0x80/0x5c8
[ 0.466727] [<0000000000100036>] startup_continue+0x36/0x40
it happens because such system tries to access some vmap areas
whereas the vmalloc initialization is not even yet done:
[ 0.465490] lock: single+0x1860/0x1958, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[ 0.466067] CPU: 0 PID: 0 Comm: swapper Not tainted 6.8.0-12955-g8e938e398669 #1
[ 0.466188] Hardware name: QEMU 8561 QEMU (KVM/Linux)
[ 0.466270] Call Trace:
[ 0.466470] dump_stack_lvl (lib/dump_stack.c:117)
[ 0.466516] do_raw_spin_lock (kernel/locking/spinlock_debug.c:87 kernel/locking/spinlock_debug.c:115)
[ 0.466545] find_vmap_area (mm/vmalloc.c:1059 mm/vmalloc.c:2364)
[ 0.466572] find_vm_area (mm/vmalloc.c:3150)
[ 0.466597] __set_memory (arch/s390/mm/pageattr.c:360 arch/s390/mm/pageattr.c:393)
[ 0.466624] vmem_map_init (./arch/s390/include/asm/set_memory.h:55 arch/s390/mm/vmem.c:660)
[ 0.466651] paging_init (arch/s390/mm/init.c:97)
[ 0.466677] setup_arch (arch/s390/kernel/setup.c:972)
[ 0.466702] start_kernel (init/main.c:899)
[ 0.466727] startup_continue (arch/s390/kernel/head64.S:35)
[ 0.466811] INFO: lockdep is turned off.
...
[ 0.718250] vmalloc init - busy lock init 0000000002871860
[ 0.718328] vmalloc init - busy lock init 00000000028731b8
Some background. It worked before because the lock that is in question
was statically defined and initialized. As of now, the locks and data
structures are initialized in the vmalloc_init() function.
To address that issue add the check whether the "vmap_initialized"
variable is set, if not find_vmap_area() bails out on entry returning NULL.
Link: https://lkml.kernel.org/r/20240323141544.4150-1-urezki@gmail.com
Fixes:
|
||
Linus Torvalds
|
902861e34c |
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series "mm:
zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is hotplugged
as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving policy
wherein we allocate memory across nodes in a weighted fashion rather
than uniformly. This is beneficial in heterogeneous memory environments
appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the process
has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown situations.
The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings" Ryan
Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's series
"Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page faults.
He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction test",
Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess in
our handling of DAX on archiecctures which have virtually aliasing data
caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides dramatic
improvements in worst-case mmap_lock hold times during certain
userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability improvements
in his series "Mitigate a vmap lock contention". It realizes a 12x
improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging of
large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages() to
an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which are
configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
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Merge tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Sumanth Korikkar has taught s390 to allocate hotplug-time page frames
from hotplugged memory rather than only from main memory. Series
"implement "memmap on memory" feature on s390".
- More folio conversions from Matthew Wilcox in the series
"Convert memcontrol charge moving to use folios"
"mm: convert mm counter to take a folio"
- Chengming Zhou has optimized zswap's rbtree locking, providing
significant reductions in system time and modest but measurable
reductions in overall runtimes. The series is "mm/zswap: optimize the
scalability of zswap rb-tree".
- Chengming Zhou has also provided the series "mm/zswap: optimize zswap
lru list" which provides measurable runtime benefits in some
swap-intensive situations.
- And Chengming Zhou further optimizes zswap in the series "mm/zswap:
optimize for dynamic zswap_pools". Measured improvements are modest.
- zswap cleanups and simplifications from Yosry Ahmed in the series
"mm: zswap: simplify zswap_swapoff()".
- In the series "Add DAX ABI for memmap_on_memory", Vishal Verma has
contributed several DAX cleanups as well as adding a sysfs tunable to
control the memmap_on_memory setting when the dax device is
hotplugged as system memory.
- Johannes Weiner has added the large series "mm: zswap: cleanups",
which does that.
- More DAMON work from SeongJae Park in the series
"mm/damon: make DAMON debugfs interface deprecation unignorable"
"selftests/damon: add more tests for core functionalities and corner cases"
"Docs/mm/damon: misc readability improvements"
"mm/damon: let DAMOS feeds and tame/auto-tune itself"
- In the series "mm/mempolicy: weighted interleave mempolicy and sysfs
extension" Rakie Kim has developed a new mempolicy interleaving
policy wherein we allocate memory across nodes in a weighted fashion
rather than uniformly. This is beneficial in heterogeneous memory
environments appearing with CXL.
- Christophe Leroy has contributed some cleanup and consolidation work
against the ARM pagetable dumping code in the series "mm: ptdump:
Refactor CONFIG_DEBUG_WX and check_wx_pages debugfs attribute".
- Luis Chamberlain has added some additional xarray selftesting in the
series "test_xarray: advanced API multi-index tests".
- Muhammad Usama Anjum has reworked the selftest code to make its
human-readable output conform to the TAP ("Test Anything Protocol")
format. Amongst other things, this opens up the use of third-party
tools to parse and process out selftesting results.
- Ryan Roberts has added fork()-time PTE batching of THP ptes in the
series "mm/memory: optimize fork() with PTE-mapped THP". Mainly
targeted at arm64, this significantly speeds up fork() when the
process has a large number of pte-mapped folios.
- David Hildenbrand also gets in on the THP pte batching game in his
series "mm/memory: optimize unmap/zap with PTE-mapped THP". It
implements batching during munmap() and other pte teardown
situations. The microbenchmark improvements are nice.
- And in the series "Transparent Contiguous PTEs for User Mappings"
Ryan Roberts further utilizes arm's pte's contiguous bit ("contpte
mappings"). Kernel build times on arm64 improved nicely. Ryan's
series "Address some contpte nits" provides some followup work.
- In the series "mm/hugetlb: Restore the reservation" Breno Leitao has
fixed an obscure hugetlb race which was causing unnecessary page
faults. He has also added a reproducer under the selftest code.
- In the series "selftests/mm: Output cleanups for the compaction
test", Mark Brown did what the title claims.
- Kinsey Ho has added the series "mm/mglru: code cleanup and
refactoring".
- Even more zswap material from Nhat Pham. The series "fix and extend
zswap kselftests" does as claimed.
- In the series "Introduce cpu_dcache_is_aliasing() to fix DAX
regression" Mathieu Desnoyers has cleaned up and fixed rather a mess
in our handling of DAX on archiecctures which have virtually aliasing
data caches. The arm architecture is the main beneficiary.
- Lokesh Gidra's series "per-vma locks in userfaultfd" provides
dramatic improvements in worst-case mmap_lock hold times during
certain userfaultfd operations.
- Some page_owner enhancements and maintenance work from Oscar Salvador
in his series
"page_owner: print stacks and their outstanding allocations"
"page_owner: Fixup and cleanup"
- Uladzislau Rezki has contributed some vmalloc scalability
improvements in his series "Mitigate a vmap lock contention". It
realizes a 12x improvement for a certain microbenchmark.
- Some kexec/crash cleanup work from Baoquan He in the series "Split
crash out from kexec and clean up related config items".
- Some zsmalloc maintenance work from Chengming Zhou in the series
"mm/zsmalloc: fix and optimize objects/page migration"
"mm/zsmalloc: some cleanup for get/set_zspage_mapping()"
- Zi Yan has taught the MM to perform compaction on folios larger than
order=0. This a step along the path to implementaton of the merging
of large anonymous folios. The series is named "Enable >0 order folio
memory compaction".
- Christoph Hellwig has done quite a lot of cleanup work in the
pagecache writeback code in his series "convert write_cache_pages()
to an iterator".
- Some modest hugetlb cleanups and speedups in Vishal Moola's series
"Handle hugetlb faults under the VMA lock".
- Zi Yan has changed the page splitting code so we can split huge pages
into sizes other than order-0 to better utilize large folios. The
series is named "Split a folio to any lower order folios".
- David Hildenbrand has contributed the series "mm: remove
total_mapcount()", a cleanup.
- Matthew Wilcox has sought to improve the performance of bulk memory
freeing in his series "Rearrange batched folio freeing".
- Gang Li's series "hugetlb: parallelize hugetlb page init on boot"
provides large improvements in bootup times on large machines which
are configured to use large numbers of hugetlb pages.
- Matthew Wilcox's series "PageFlags cleanups" does that.
- Qi Zheng's series "minor fixes and supplement for ptdesc" does that
also. S390 is affected.
- Cleanups to our pagemap utility functions from Peter Xu in his series
"mm/treewide: Replace pXd_large() with pXd_leaf()".
- Nico Pache has fixed a few things with our hugepage selftests in his
series "selftests/mm: Improve Hugepage Test Handling in MM
Selftests".
- Also, of course, many singleton patches to many things. Please see
the individual changelogs for details.
* tag 'mm-stable-2024-03-13-20-04' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (435 commits)
mm/zswap: remove the memcpy if acomp is not sleepable
crypto: introduce: acomp_is_async to expose if comp drivers might sleep
memtest: use {READ,WRITE}_ONCE in memory scanning
mm: prohibit the last subpage from reusing the entire large folio
mm: recover pud_leaf() definitions in nopmd case
selftests/mm: skip the hugetlb-madvise tests on unmet hugepage requirements
selftests/mm: skip uffd hugetlb tests with insufficient hugepages
selftests/mm: dont fail testsuite due to a lack of hugepages
mm/huge_memory: skip invalid debugfs new_order input for folio split
mm/huge_memory: check new folio order when split a folio
mm, vmscan: retry kswapd's priority loop with cache_trim_mode off on failure
mm: add an explicit smp_wmb() to UFFDIO_CONTINUE
mm: fix list corruption in put_pages_list
mm: remove folio from deferred split list before uncharging it
filemap: avoid unnecessary major faults in filemap_fault()
mm,page_owner: drop unnecessary check
mm,page_owner: check for null stack_record before bumping its refcount
mm: swap: fix race between free_swap_and_cache() and swapoff()
mm/treewide: align up pXd_leaf() retval across archs
mm/treewide: drop pXd_large()
...
|
||
Alexei Starovoitov
|
d7bca9199a |
mm: Introduce vmap_page_range() to map pages in PCI address space
ioremap_page_range() should be used for ranges within vmalloc range only.
The vmalloc ranges are allocated by get_vm_area(). PCI has "resource"
allocator that manages PCI_IOBASE, IO_SPACE_LIMIT address range, hence
introduce vmap_page_range() to be used exclusively to map pages
in PCI address space.
Fixes:
|
||
|
Alexei Starovoitov
|
e6f798225a |
mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages().
vmap/vmalloc APIs are used to map a set of pages into contiguous kernel virtual space. get_vm_area() with appropriate flag is used to request an area of kernel address range. It's used for vmalloc, vmap, ioremap, xen use cases. - vmalloc use case dominates the usage. Such vm areas have VM_ALLOC flag. - the areas created by vmap() function should be tagged with VM_MAP. - ioremap areas are tagged with VM_IOREMAP. BPF would like to extend the vmap API to implement a lazily-populated sparse, yet contiguous kernel virtual space. Introduce VM_SPARSE flag and vm_area_map_pages(area, start_addr, count, pages) API to map a set of pages within a given area. It has the same sanity checks as vmap() does. It also checks that get_vm_area() was created with VM_SPARSE flag which identifies such areas in /proc/vmallocinfo and returns zero pages on read through /proc/kcore. The next commits will introduce bpf_arena which is a sparsely populated shared memory region between bpf program and user space process. It will map privately-managed pages into a sparse vm area with the following steps: // request virtual memory region during bpf prog verification area = get_vm_area(area_size, VM_SPARSE); // on demand vm_area_map_pages(area, kaddr, kend, pages); vm_area_unmap_pages(area, kaddr, kend); // after bpf program is detached and unloaded free_vm_area(area); Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Link: https://lore.kernel.org/bpf/20240305030516.41519-3-alexei.starovoitov@gmail.com |
||
|
Alexei Starovoitov
|
3e49a866c9 |
mm: Enforce VM_IOREMAP flag and range in ioremap_page_range.
There are various users of get_vm_area() + ioremap_page_range() APIs. Enforce that get_vm_area() was requested as VM_IOREMAP type and range passed to ioremap_page_range() matches created vm_area to avoid accidentally ioremap-ing into wrong address range. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/bpf/20240305030516.41519-2-alexei.starovoitov@gmail.com |
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Uladzislau Rezki (Sony)
|
8be4d46e12 |
mm: vmalloc: refactor vmalloc_dump_obj() function
This patch tends to simplify the function in question, by removing an extra stack "objp" variable, returning back to an early exit approach if spin_trylock() fails or VA was not found. Link: https://lkml.kernel.org/r/20240124180920.50725-2-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
15e02a39fb |
mm: vmalloc: improve description of vmap node layer
This patch adds extra explanation of recently added vmap node layer based on community feedback. No functional change. Link: https://lkml.kernel.org/r/20240124180920.50725-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
7679ba6b36 |
mm: vmalloc: add a shrinker to drain vmap pools
The added shrinker is used to return back current cached VAs into a global vmap space, when a system enters into a low memory mode. Link: https://lkml.kernel.org/r/20240102184633.748113-12-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
8f33a2ff30 |
mm: vmalloc: set nr_nodes based on CPUs in a system
A number of nodes which are used in the alloc/free paths is set based on num_possible_cpus() in a system. Please note a high limit threshold though is fixed and corresponds to 128 nodes. For 32-bit or single core systems an access to a global vmap heap is not balanced. Such small systems do not suffer from lock contentions due to low number of CPUs. In such case the nr_nodes is equal to 1. Test on AMD Ryzen Threadripper 3970X 32-Core Processor: sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 <default perf> 94.41% 0.89% [kernel] [k] _raw_spin_lock 93.35% 93.07% [kernel] [k] native_queued_spin_lock_slowpath 76.13% 0.28% [kernel] [k] __vmalloc_node_range 72.96% 0.81% [kernel] [k] alloc_vmap_area 56.94% 0.00% [kernel] [k] __get_vm_area_node 41.95% 0.00% [kernel] [k] vmalloc 37.15% 0.01% [test_vmalloc] [k] full_fit_alloc_test 35.17% 0.00% [kernel] [k] ret_from_fork_asm 35.17% 0.00% [kernel] [k] ret_from_fork 35.17% 0.00% [kernel] [k] kthread 35.08% 0.00% [test_vmalloc] [k] test_func 34.45% 0.00% [test_vmalloc] [k] fix_size_alloc_test 28.09% 0.01% [test_vmalloc] [k] long_busy_list_alloc_test 23.53% 0.25% [kernel] [k] vfree.part.0 21.72% 0.00% [kernel] [k] remove_vm_area 20.08% 0.21% [kernel] [k] find_unlink_vmap_area 2.34% 0.61% [kernel] [k] free_vmap_area_noflush <default perf> vs <patch-series perf> 82.32% 0.22% [test_vmalloc] [k] long_busy_list_alloc_test 63.36% 0.02% [kernel] [k] vmalloc 63.34% 2.64% [kernel] [k] __vmalloc_node_range 30.42% 4.46% [kernel] [k] vfree.part.0 28.98% 2.51% [kernel] [k] __alloc_pages_bulk 27.28% 0.19% [kernel] [k] __get_vm_area_node 26.13% 1.50% [kernel] [k] alloc_vmap_area 21.72% 21.67% [kernel] [k] clear_page_rep 19.51% 2.43% [kernel] [k] _raw_spin_lock 16.61% 16.51% [kernel] [k] native_queued_spin_lock_slowpath 13.40% 2.07% [kernel] [k] free_unref_page 10.62% 0.01% [kernel] [k] remove_vm_area 9.02% 8.73% [kernel] [k] insert_vmap_area 8.94% 0.00% [kernel] [k] ret_from_fork_asm 8.94% 0.00% [kernel] [k] ret_from_fork 8.94% 0.00% [kernel] [k] kthread 8.29% 0.00% [test_vmalloc] [k] test_func 7.81% 0.05% [test_vmalloc] [k] full_fit_alloc_test 5.30% 4.73% [kernel] [k] purge_vmap_node 4.47% 2.65% [kernel] [k] free_vmap_area_noflush <patch-series perf> confirms that a native_queued_spin_lock_slowpath goes down to 16.51% percent from 93.07%. The throughput is ~12x higher: urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 10m51.271s user 0m0.013s sys 0m0.187s urezki@pc638:~$ urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64 Run the test with following parameters: run_test_mask=7 nr_threads=64 Done. Check the kernel ring buffer to see the summary. real 0m51.301s user 0m0.015s sys 0m0.040s urezki@pc638:~$ Link: https://lkml.kernel.org/r/20240102184633.748113-11-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
8e1d743f2c |
mm: vmalloc: support multiple nodes in vmallocinfo
Allocated areas are spread among nodes, it implies that the scanning has to be performed individually of each node in order to dump all existing VAs. Link: https://lkml.kernel.org/r/20240102184633.748113-10-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
53becf32ae |
mm: vmalloc: support multiple nodes in vread_iter
Extend the vread_iter() to be able to perform a sequential reading of VAs which are spread among multiple nodes. So a data read over the /dev/kmem correctly reflects a vmalloc memory layout. Link: https://lkml.kernel.org/r/20240102184633.748113-9-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
96aa8437d1 |
mm: vmalloc: add a scan area of VA only once
Invoke a kmemleak_scan_area() function only for newly allocated objects to add a scan area within that object. There is no reason to add a same scan area(pointer to beginning or inside the object) several times. If a VA is obtained from the cache its scan area has already been associated. Link: https://lkml.kernel.org/r/20240202190628.47806-1-urezki@gmail.com Fixes: 7db166b4aa0d ("mm: vmalloc: offload free_vmap_area_lock lock") Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
72210662c5 |
mm: vmalloc: offload free_vmap_area_lock lock
Concurrent access to a global vmap space is a bottle-neck. We can simulate a high contention by running a vmalloc test suite. To address it, introduce an effective vmap node logic. Each node behaves as independent entity. When a node is accessed it serves a request directly(if possible) from its pool. This model has a size based pool for requests, i.e. pools are serialized and populated based on object size and real demand. A maximum object size that pool can handle is set to 256 pages. This technique reduces a pressure on the global vmap lock. Link: https://lkml.kernel.org/r/20240102184633.748113-8-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
282631cb24 |
mm: vmalloc: remove global purge_vmap_area_root rb-tree
Similar to busy VA, lazily-freed area is stored to a node it belongs to. Such approach does not require any global locking primitive, instead an access becomes scalable what mitigates a contention. This patch removes a global purge-lock, global purge-tree and global purge list. Link: https://lkml.kernel.org/r/20240102184633.748113-7-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Baoquan He
|
55c49fee57 |
mm/vmalloc: remove vmap_area_list
Earlier, vmap_area_list is exported to vmcoreinfo so that makedumpfile get the base address of vmalloc area. Now, vmap_area_list is empty, so export VMALLOC_START to vmcoreinfo instead, and remove vmap_area_list. [urezki@gmail.com: fix a warning in the crash_save_vmcoreinfo_init()] Link: https://lkml.kernel.org/r/20240111192329.449189-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20240102184633.748113-6-urezki@gmail.com Signed-off-by: Baoquan He <bhe@redhat.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
d093602919 |
mm: vmalloc: remove global vmap_area_root rb-tree
Store allocated objects in a separate nodes. A va->va_start address is converted into a correct node where it should be placed and resided. An addr_to_node() function is used to do a proper address conversion to determine a node that contains a VA. Such approach balances VAs across nodes as a result an access becomes scalable. Number of nodes in a system depends on number of CPUs. Please note: 1. As of now allocated VAs are bound to a node-0. It means the patch does not give any difference comparing with a current behavior; 2. The global vmap_area_lock, vmap_area_root are removed as there is no need in it anymore. The vmap_area_list is still kept and is _empty_. It is exported for a kexec only; 3. The vmallocinfo and vread() have to be reworked to be able to handle multiple nodes. [urezki@gmail.com: mark vmap_init_free_space() with __init tag] Link: https://lkml.kernel.org/r/20240111132628.299644-1-urezki@gmail.com [urezki@gmail.com: fix a wrong value passed to __find_vmap_area()] Link: https://lkml.kernel.org/r/20240111121104.180993-1-urezki@gmail.com Link: https://lkml.kernel.org/r/20240102184633.748113-5-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
7fa8cee003 |
mm: vmalloc: move vmap_init_free_space() down in vmalloc.c
A vmap_init_free_space() is a function that setups a vmap space and is considered as part of initialization phase. Since a main entry which is vmalloc_init(), has been moved down in vmalloc.c it makes sense to follow the pattern. There is no a functional change as a result of this patch. Link: https://lkml.kernel.org/r/20240102184633.748113-4-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
5b75b8e1b9 |
mm: vmalloc: rename adjust_va_to_fit_type() function
This patch renames the adjust_va_to_fit_type() function to va_clip() which is shorter and more expressive. There is no a functional change as a result of this patch. Link: https://lkml.kernel.org/r/20240102184633.748113-3-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Joel Fernandes (Google) <joel@joelfernandes.org> Cc: Kazuhito Hagio <k-hagio-ab@nec.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Uladzislau Rezki (Sony)
|
38f6b9af04 |
mm: vmalloc: add va_alloc() helper
Patch series "Mitigate a vmap lock contention", v3.
1. Motivation
- Offload global vmap locks making it scaled to number of CPUS;
- If possible and there is an agreement, we can remove the "Per cpu kva
allocator" to make the vmap code to be more simple;
- There were complaints from XFS folk that a vmalloc might be contented
on their workloads.
2. Design(high level overview)
We introduce an effective vmap node logic. A node behaves as independent
entity to serve an allocation request directly(if possible) from its pool.
That way it bypasses a global vmap space that is protected by its own
lock.
An access to pools are serialized by CPUs. Number of nodes are equal to
number of CPUs in a system. Please note the high threshold is bound to
128 nodes.
Pools are size segregated and populated based on system demand. The
maximum alloc request that can be stored into a segregated storage is 256
pages. The lazily drain path decays a pool by 25% as a first step and as
second populates it by fresh freed VAs for reuse instead of returning them
into a global space.
When a VA is obtained(alloc path), it is stored in separate nodes. A
va->va_start address is converted into a correct node where it should be
placed and resided. Doing so we balance VAs across the nodes as a result
an access becomes scalable. The addr_to_node() function does a proper
address conversion to a correct node.
A vmap space is divided on segments with fixed size, it is 16 pages. That
way any address can be associated with a segment number. Number of
segments are equal to num_possible_cpus() but not grater then 128. The
numeration starts from 0. See below how it is converted:
static inline unsigned int
addr_to_node_id(unsigned long addr)
{
return (addr / zone_size) % nr_nodes;
}
On a free path, a VA can be easily found by converting its "va_start"
address to a certain node it resides. It is moved from "busy" data to
"lazy" data structure. Later on, as noted earlier, the lazy kworker
decays each node pool and populates it by fresh incoming VAs. Please
note, a VA is returned to a node that did an alloc request.
3. Test on AMD Ryzen Threadripper 3970X 32-Core Processor
sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64
<default perf>
94.41% 0.89% [kernel] [k] _raw_spin_lock
93.35% 93.07% [kernel] [k] native_queued_spin_lock_slowpath
76.13% 0.28% [kernel] [k] __vmalloc_node_range
72.96% 0.81% [kernel] [k] alloc_vmap_area
56.94% 0.00% [kernel] [k] __get_vm_area_node
41.95% 0.00% [kernel] [k] vmalloc
37.15% 0.01% [test_vmalloc] [k] full_fit_alloc_test
35.17% 0.00% [kernel] [k] ret_from_fork_asm
35.17% 0.00% [kernel] [k] ret_from_fork
35.17% 0.00% [kernel] [k] kthread
35.08% 0.00% [test_vmalloc] [k] test_func
34.45% 0.00% [test_vmalloc] [k] fix_size_alloc_test
28.09% 0.01% [test_vmalloc] [k] long_busy_list_alloc_test
23.53% 0.25% [kernel] [k] vfree.part.0
21.72% 0.00% [kernel] [k] remove_vm_area
20.08% 0.21% [kernel] [k] find_unlink_vmap_area
2.34% 0.61% [kernel] [k] free_vmap_area_noflush
<default perf>
vs
<patch-series perf>
82.32% 0.22% [test_vmalloc] [k] long_busy_list_alloc_test
63.36% 0.02% [kernel] [k] vmalloc
63.34% 2.64% [kernel] [k] __vmalloc_node_range
30.42% 4.46% [kernel] [k] vfree.part.0
28.98% 2.51% [kernel] [k] __alloc_pages_bulk
27.28% 0.19% [kernel] [k] __get_vm_area_node
26.13% 1.50% [kernel] [k] alloc_vmap_area
21.72% 21.67% [kernel] [k] clear_page_rep
19.51% 2.43% [kernel] [k] _raw_spin_lock
16.61% 16.51% [kernel] [k] native_queued_spin_lock_slowpath
13.40% 2.07% [kernel] [k] free_unref_page
10.62% 0.01% [kernel] [k] remove_vm_area
9.02% 8.73% [kernel] [k] insert_vmap_area
8.94% 0.00% [kernel] [k] ret_from_fork_asm
8.94% 0.00% [kernel] [k] ret_from_fork
8.94% 0.00% [kernel] [k] kthread
8.29% 0.00% [test_vmalloc] [k] test_func
7.81% 0.05% [test_vmalloc] [k] full_fit_alloc_test
5.30% 4.73% [kernel] [k] purge_vmap_node
4.47% 2.65% [kernel] [k] free_vmap_area_noflush
<patch-series perf>
confirms that a native_queued_spin_lock_slowpath goes down to
16.51% percent from 93.07%.
The throughput is ~12x higher:
urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64
Run the test with following parameters: run_test_mask=7 nr_threads=64
Done.
Check the kernel ring buffer to see the summary.
real 10m51.271s
user 0m0.013s
sys 0m0.187s
urezki@pc638:~$
urezki@pc638:~$ time sudo ./test_vmalloc.sh run_test_mask=7 nr_threads=64
Run the test with following parameters: run_test_mask=7 nr_threads=64
Done.
Check the kernel ring buffer to see the summary.
real 0m51.301s
user 0m0.015s
sys 0m0.040s
urezki@pc638:~$
This patch (of 11):
Currently __alloc_vmap_area() function contains an open codded logic that
finds and adjusts a VA based on allocation request.
Introduce a va_alloc() helper that adjusts found VA only. There is no a
functional change as a result of this patch.
Link: https://lkml.kernel.org/r/20240102184633.748113-1-urezki@gmail.com
Link: https://lkml.kernel.org/r/20240102184633.748113-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Kazuhito Hagio <k-hagio-ab@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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||
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Baoquan He
|
ca6c2ce1b4 |
mm/vmalloc: fix the unchecked dereference warning in vread_iter()
LKP reported smatch warning as below: =================== smatch warnings: mm/vmalloc.c:3689 vread_iter() error: we previously assumed 'vm' could be null (see line 3667) ...... |
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Ryan Roberts
|
935d4f0c6d |
mm: hugetlb: add huge page size param to set_huge_pte_at()
Patch series "Fix set_huge_pte_at() panic on arm64", v2. This series fixes a bug in arm64's implementation of set_huge_pte_at(), which can result in an unprivileged user causing a kernel panic. The problem was triggered when running the new uffd poison mm selftest for HUGETLB memory. This test (and the uffd poison feature) was merged for v6.5-rc7. Ideally, I'd like to get this fix in for v6.6 and I've cc'ed stable (correctly this time) to get it backported to v6.5, where the issue first showed up. Description of Bug ================== arm64's huge pte implementation supports multiple huge page sizes, some of which are implemented in the page table with multiple contiguous entries. So set_huge_pte_at() needs to work out how big the logical pte is, so that it can also work out how many physical ptes (or pmds) need to be written. It previously did this by grabbing the folio out of the pte and querying its size. However, there are cases when the pte being set is actually a swap entry. But this also used to work fine, because for huge ptes, we only ever saw migration entries and hwpoison entries. And both of these types of swap entries have a PFN embedded, so the code would grab that and everything still worked out. But over time, more calls to set_huge_pte_at() have been added that set swap entry types that do not embed a PFN. And this causes the code to go bang. The triggering case is for the uffd poison test, commit |
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Joel Fernandes (Google)
|
0818e739b5 |
mm/vmalloc: add a safer version of find_vm_area() for debug
It is unsafe to dump vmalloc area information when trying to do so from
some contexts. Add a safer trylock version of the same function to do a
best-effort VMA finding and use it from vmalloc_dump_obj().
[applied test robot feedback on unused function fix.]
[applied Uladzislau feedback on locking.]
Link: https://lkml.kernel.org/r/20230904180806.1002832-1-joel@joelfernandes.org
Fixes:
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Alexandre Ghiti
|
a50420c797 |
mm: add a call to flush_cache_vmap() in vmap_pfn()
flush_cache_vmap() must be called after new vmalloc mappings are installed in the page table in order to allow architectures to make sure the new mapping is visible. It could lead to a panic since on some architectures (like powerpc), the page table walker could see the wrong pte value and trigger a spurious page fault that can not be resolved (see commit |
||
Andrew Morton
|
63773d2b59 | Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. | ||
|
Ryan Roberts
|
c33c794828 |
mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Hugh Dickins
|
0d1c81edc6 |
mm/vmalloc: vmalloc_to_page() use pte_offset_kernel()
vmalloc_to_page() was using pte_offset_map() (followed by pte_unmap()), but it's intended for userspace page tables: prefer pte_offset_kernel(). Link: https://lkml.kernel.org/r/696386a-84f8-b33c-82e5-f865ed6eb39@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lu Hongfei
|
0e4bc27111 |
mm/vmalloc: replace the ternary conditional operator with min()
It would be better to replace the traditional ternary conditional operator with min() in zero_iter Link: https://lkml.kernel.org/r/20230609093057.27777-1-luhongfei@vivo.com Signed-off-by: Lu Hongfei <luhongfei@vivo.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
|
95a301eefa |
mm/vmalloc: do not output a spurious warning when huge vmalloc() fails
In __vmalloc_area_node() we always warn_alloc() when an allocation
performed by vm_area_alloc_pages() fails unless it was due to a pending
fatal signal.
However, huge page allocations instigated either by vmalloc_huge() or
__vmalloc_node_range() (or a caller that invokes this like kvmalloc() or
kvmalloc_node()) always falls back to order-0 allocations if the huge page
allocation fails.
This renders the warning useless and noisy, especially as all callers
appear to be aware that this may fallback. This has already resulted in
at least one bug report from a user who was confused by this (see link).
Therefore, simply update the code to only output this warning for order-0
pages when no fatal signal is pending.
Link: https://bugzilla.suse.com/show_bug.cgi?id=1211410
Link: https://lkml.kernel.org/r/20230605201107.83298-1-lstoakes@gmail.com
Fixes:
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Ryan Roberts
|
b3f78e7498 |
mm: vmalloc must set pte via arch code
Patch series "Fixes for pte encapsulation bypasses", v3.
A series to improve the encapsulation of pte entries by disallowing
non-arch code from directly dereferencing pte_t pointers.
This patch (of 4):
It is bad practice to directly set pte entries within a pte table.
Instead all modifications must go through arch-provided helpers such as
set_pte_at() to give the arch code visibility and allow it to check (and
potentially modify) the operation.
Link: https://lkml.kernel.org/r/20230602092949.545577-1-ryan.roberts@arm.com
Link: https://lkml.kernel.org/r/20230602092949.545577-2-ryan.roberts@arm.com
Fixes:
|
||
Thomas Gleixner
|
77e50af07f |
mm/vmalloc: dont purge usable blocks unnecessarily
Purging fragmented blocks is done unconditionally in several contexts:
1) From drain_vmap_area_work(), when the number of lazy to be freed
vmap_areas reached the threshold
2) Reclaiming vmalloc address space from pcpu_get_vm_areas()
3) _vm_unmap_aliases()
#1 There is no reason to zap fragmented vmap blocks unconditionally, simply
because reclaiming all lazy areas drains at least
32MB * fls(num_online_cpus())
per invocation which is plenty.
#2 Reclaiming when running out of space or due to memory pressure makes a
lot of sense
#3 _unmap_aliases() requires to touch everything because the caller has no
clue which vmap_area used a particular page last and the vmap_area lost
that information too.
Except for the vfree + VM_FLUSH_RESET_PERMS case, which removes the
vmap area first and then cares about the flush. That in turn requires
a full walk of _all_ vmap areas including the one which was just
added to the purge list.
But as this has to be flushed anyway this is an opportunity to combine
outstanding TLB flushes and do the housekeeping of purging freed areas,
but like #1 there is no real good reason to zap usable vmap blocks
unconditionally.
Add a @force_purge argument to the newly split out block purge function and
if not true only purge fragmented blocks which have less than 1/4 of their
capacity left.
Rename purge_vmap_area_lazy() to reclaim_and_purge_vmap_areas() to make it
clear what the function does.
[lstoakes@gmail.com: correct VMAP_PURGE_THRESHOLD check]
Link: https://lkml.kernel.org/r/3e92ef61-b910-4576-88e7-cf43211fd4e7@lucifer.local
Link: https://lkml.kernel.org/r/20230525124504.864005691@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Thomas Gleixner
|
7f48121e9f |
mm/vmalloc: add missing READ/WRITE_ONCE() annotations
purge_fragmented_blocks() accesses vmap_block::free and vmap_block::dirty lockless for a quick check. Add the missing READ/WRITE_ONCE() annotations. Link: https://lkml.kernel.org/r/20230525124504.807356682@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Thomas Gleixner
|
43d7650234 |
mm/vmalloc: check free space in vmap_block lockless
vb_alloc() unconditionally locks a vmap_block on the free list to check the free space. This can be done locklessly because vmap_block::free never increases, it's only decreased on allocations. Check the free space lockless and only if that succeeds, recheck under the lock. Link: https://lkml.kernel.org/r/20230525124504.750481992@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Thomas Gleixner
|
a09fad96ff |
mm/vmalloc: prevent flushing dirty space over and over
vmap blocks which have active mappings cannot be purged. Allocations which have been freed are accounted for in vmap_block::dirty_min/max, so that they can be detected in _vm_unmap_aliases() as potentially stale TLBs. If there are several invocations of _vm_unmap_aliases() then each of them will flush the dirty range. That's pointless and just increases the probability of full TLB flushes. Avoid that by resetting the flush range after accounting for it. That's safe versus other invocations of _vm_unmap_aliases() because this is all serialized with vmap_purge_lock. Link: https://lkml.kernel.org/r/20230525124504.692056496@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Thomas Gleixner
|
ca5e46c340 |
mm/vmalloc: avoid iterating over per CPU vmap blocks twice
_vunmap_aliases() walks the per CPU xarrays to find partially unmapped
blocks and then walks the per cpu free lists to purge fragmented blocks.
Arguably that's waste of CPU cycles and cache lines as the full xarray
walk already touches every block.
Avoid this double iteration:
- Split out the code to purge one block and the code to free the local
purge list into helper functions.
- Try to purge the fragmented blocks in the xarray walk before looking at
their dirty space.
Link: https://lkml.kernel.org/r/20230525124504.633469722@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Thomas Gleixner
|
fc1e0d9800 |
mm/vmalloc: prevent stale TLBs in fully utilized blocks
Patch series "mm/vmalloc: Assorted fixes and improvements", v2.
this series addresses the following issues:
1) Prevent the stale TLB problem related to fully utilized vmap blocks
2) Avoid the double per CPU list walk in _vm_unmap_aliases()
3) Avoid flushing dirty space over and over
4) Add a lockless quickcheck in vb_alloc() and add missing
READ/WRITE_ONCE() annotations
5) Prevent overeager purging of usable vmap_blocks if
not under memory/address space pressure.
This patch (of 6):
_vm_unmap_aliases() is used to ensure that no unflushed TLB entries for a
page are left in the system. This is required due to the lazy TLB flush
mechanism in vmalloc.
This is tried to achieve by walking the per CPU free lists, but those do
not contain fully utilized vmap blocks because they are removed from the
free list once the blocks free space became zero.
When the block is not fully unmapped then it is not on the purge list
either.
So neither the per CPU list iteration nor the purge list walk find the
block and if the page was mapped via such a block and the TLB has not yet
been flushed, the guarantee of _vm_unmap_aliases() that there are no stale
TLBs after returning is broken:
x = vb_alloc() // Removes vmap_block from free list because vb->free became 0
vb_free(x) // Unmaps page and marks in dirty_min/max range
// Block has still mappings and is not put on purge list
// Page is reused
vm_unmap_aliases() // Can't find vmap block with the dirty space -> FAIL
So instead of walking the per CPU free lists, walk the per CPU xarrays
which hold pointers to _all_ active blocks in the system including those
removed from the free lists.
Link: https://lkml.kernel.org/r/20230525122342.109672430@linutronix.de
Link: https://lkml.kernel.org/r/20230525124504.573987880@linutronix.de
Fixes:
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|
Uladzislau Rezki (Sony)
|
fa1c77c13c |
mm: vmalloc: rename addr_to_vb_xarray() function
Short the name of the addr_to_vb_xarray() function to the addr_to_vb_xa(). This aligns with other internal function abbreviations. Link: https://lkml.kernel.org/r/20230331073727.6968-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Suggested-by: Baoquan He <bhe@redhat.com> Reviewed-by: Baoquan He <bhe@redhat.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Uladzislau Rezki (Sony)
|
062eacf57a |
mm: vmalloc: remove a global vmap_blocks xarray
A global vmap_blocks-xarray array can be contented under heavy usage of the vm_map_ram()/vm_unmap_ram() APIs. The lock_stat shows that a "vmap_blocks.xa_lock" lock is a second in a top-list when it comes to contentions: <snip> ---------------------------------------- class name con-bounces contentions ... ---------------------------------------- vmap_area_lock: 2554079 2554276 ... -------------- vmap_area_lock 1297948 [<00000000dd41cbaa>] alloc_vmap_area+0x1c7/0x910 vmap_area_lock 1256330 [<000000009d927bf3>] free_vmap_block+0x4a/0xe0 vmap_area_lock 1 [<00000000c95c05a7>] find_vm_area+0x16/0x70 -------------- vmap_area_lock 1738590 [<00000000dd41cbaa>] alloc_vmap_area+0x1c7/0x910 vmap_area_lock 815688 [<000000009d927bf3>] free_vmap_block+0x4a/0xe0 vmap_area_lock 1 [<00000000c1d619d7>] __get_vm_area_node+0xd2/0x170 vmap_blocks.xa_lock: 862689 862698 ... ------------------- vmap_blocks.xa_lock 378418 [<00000000625a5626>] vm_map_ram+0x359/0x4a0 vmap_blocks.xa_lock 484280 [<00000000caa2ef03>] xa_erase+0xe/0x30 ------------------- vmap_blocks.xa_lock 576226 [<00000000caa2ef03>] xa_erase+0xe/0x30 vmap_blocks.xa_lock 286472 [<00000000625a5626>] vm_map_ram+0x359/0x4a0 ... <snip> that is a result of running vm_map_ram()/vm_unmap_ram() in a loop. The test creates 64(on 64 CPUs system) threads and each one maps/unmaps 1 page. After this change the "xa_lock" can be considered as a noise in the same test condition: <snip> ... &xa->xa_lock#1: 10333 10394 ... -------------- &xa->xa_lock#1 5349 [<00000000bbbc9751>] xa_erase+0xe/0x30 &xa->xa_lock#1 5045 [<0000000018def45d>] vm_map_ram+0x3a4/0x4f0 -------------- &xa->xa_lock#1 7326 [<0000000018def45d>] vm_map_ram+0x3a4/0x4f0 &xa->xa_lock#1 3068 [<00000000bbbc9751>] xa_erase+0xe/0x30 ... <snip> Running the test_vmalloc.sh run_test_mask=1024 nr_threads=64 nr_pages=5 shows around ~8 percent of throughput improvement of vm_map_ram() and vm_unmap_ram() APIs. This patch does not fix vmap_area_lock/free_vmap_area_lock and purge_vmap_area_lock bottle-necks, it is rather a separate rework. Link: https://lkml.kernel.org/r/20230330190639.431589-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Andrew Morton
|
f8f238ffe5 | sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes | ||
Alexander Potapenko
|
fdea03e12a |
mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()
Similarly to kmsan_vmap_pages_range_noflush(), kmsan_ioremap_page_range()
must also properly handle allocation/mapping failures. In the case of
such, it must clean up the already created metadata mappings and return an
error code, so that the error can be propagated to ioremap_page_range().
Without doing so, KMSAN may silently fail to bring the metadata for the
page range into a consistent state, which will result in user-visible
crashes when trying to access them.
Link: https://lkml.kernel.org/r/20230413131223.4135168-2-glider@google.com
Fixes:
|
||
|
Alexander Potapenko
|
47ebd0310e |
mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()
As reported by Dipanjan Das, when KMSAN is used together with kernel fault
injection (or, generally, even without the latter), calls to kcalloc() or
__vmap_pages_range_noflush() may fail, leaving the metadata mappings for
the virtual mapping in an inconsistent state. When these metadata
mappings are accessed later, the kernel crashes.
To address the problem, we return a non-zero error code from
kmsan_vmap_pages_range_noflush() in the case of any allocation/mapping
failure inside it, and make vmap_pages_range_noflush() return an error if
KMSAN fails to allocate the metadata.
This patch also removes KMSAN_WARN_ON() from vmap_pages_range_noflush(),
as these allocation failures are not fatal anymore.
Link: https://lkml.kernel.org/r/20230413131223.4135168-1-glider@google.com
Fixes:
|
||
|
Andrew Morton
|
e492cd61b9 | sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changes | ||
|
Lorenzo Stoakes
|
4c91c07c93 |
mm: vmalloc: convert vread() to vread_iter()
Having previously laid the foundation for converting vread() to an iterator function, pull the trigger and do so. This patch attempts to provide minimal refactoring and to reflect the existing logic as best we can, for example we continue to zero portions of memory not read, as before. Overall, there should be no functional difference other than a performance improvement in /proc/kcore access to vmalloc regions. Now we have eliminated the need for a bounce buffer in read_kcore_iter(), we dispense with it, and try to write to user memory optimistically but with faults disabled via copy_page_to_iter_nofault(). We already have preemption disabled by holding a spin lock. We continue faulting in until the operation is complete. Additionally, we must account for the fact that at any point a copy may fail (most likely due to a fault not being able to occur), we exit indicating fewer bytes retrieved than expected. [sfr@canb.auug.org.au: fix sparc64 warning] Link: https://lkml.kernel.org/r/20230320144721.663280c3@canb.auug.org.au [lstoakes@gmail.com: redo Stephen's sparc build fix] Link: https://lkml.kernel.org/r/8506cbc667c39205e65a323f750ff9c11a463798.1679566220.git.lstoakes@gmail.com [akpm@linux-foundation.org: unbreak uio.h includes] Link: https://lkml.kernel.org/r/941f88bc5ab928e6656e1e2593b91bf0f8c81e1b.1679511146.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by: Baoquan He <bhe@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David Hildenbrand <david@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Liu Shixin <liushixin2@huawei.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Yafang Shao
|
f349b15e18 |
mm: vmalloc: avoid warn_alloc noise caused by fatal signal
There're some suspicious warn_alloc on my test serer, for example, [13366.518837] warn_alloc: 81 callbacks suppressed [13366.518841] test_verifier: vmalloc error: size 4096, page order 0, failed to allocate pages, mode:0x500dc2(GFP_HIGHUSER|__GFP_ZERO|__GFP_ACCOUNT), nodemask=(null),cpuset=/,mems_allowed=0-1 [13366.522240] CPU: 30 PID: 722463 Comm: test_verifier Kdump: loaded Tainted: G W O 6.2.0+ #638 [13366.524216] Call Trace: [13366.524702] <TASK> [13366.525148] dump_stack_lvl+0x6c/0x80 [13366.525712] dump_stack+0x10/0x20 [13366.526239] warn_alloc+0x119/0x190 [13366.526783] ? alloc_pages_bulk_array_mempolicy+0x9e/0x2a0 [13366.527470] __vmalloc_area_node+0x546/0x5b0 [13366.528066] __vmalloc_node_range+0xc2/0x210 [13366.528660] __vmalloc_node+0x42/0x50 [13366.529186] ? bpf_prog_realloc+0x53/0xc0 [13366.529743] __vmalloc+0x1e/0x30 [13366.530235] bpf_prog_realloc+0x53/0xc0 [13366.530771] bpf_patch_insn_single+0x80/0x1b0 [13366.531351] bpf_jit_blind_constants+0xe9/0x1c0 [13366.531932] ? __free_pages+0xee/0x100 [13366.532457] ? free_large_kmalloc+0x58/0xb0 [13366.533002] bpf_int_jit_compile+0x8c/0x5e0 [13366.533546] bpf_prog_select_runtime+0xb4/0x100 [13366.534108] bpf_prog_load+0x6b1/0xa50 [13366.534610] ? perf_event_task_tick+0x96/0xb0 [13366.535151] ? security_capable+0x3a/0x60 [13366.535663] __sys_bpf+0xb38/0x2190 [13366.536120] ? kvm_clock_get_cycles+0x9/0x10 [13366.536643] __x64_sys_bpf+0x1c/0x30 [13366.537094] do_syscall_64+0x38/0x90 [13366.537554] entry_SYSCALL_64_after_hwframe+0x72/0xdc [13366.538107] RIP: 0033:0x7f78310f8e29 [13366.538561] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 17 e0 2c 00 f7 d8 64 89 01 48 [13366.540286] RSP: 002b:00007ffe2a61fff8 EFLAGS: 00000206 ORIG_RAX: 0000000000000141 [13366.541031] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f78310f8e29 [13366.541749] RDX: 0000000000000080 RSI: 00007ffe2a6200b0 RDI: 0000000000000005 [13366.542470] RBP: 00007ffe2a620010 R08: 00007ffe2a6202a0 R09: 00007ffe2a6200b0 [13366.543183] R10: 00000000000f423e R11: 0000000000000206 R12: 0000000000407800 [13366.543900] R13: 00007ffe2a620540 R14: 0000000000000000 R15: 0000000000000000 [13366.544623] </TASK> [13366.545260] Mem-Info: [13366.546121] active_anon:81319 inactive_anon:20733 isolated_anon:0 active_file:69450 inactive_file:5624 isolated_file:0 unevictable:0 dirty:10 writeback:0 slab_reclaimable:69649 slab_unreclaimable:48930 mapped:27400 shmem:12868 pagetables:4929 sec_pagetables:0 bounce:0 kernel_misc_reclaimable:0 free:15870308 free_pcp:142935 free_cma:0 [13366.551886] Node 0 active_anon:224836kB inactive_anon:33528kB active_file:175692kB inactive_file:13752kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:59248kB dirty:32kB writeback:0kB shmem:18252kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB kernel_stack:4616kB pagetables:10664kB sec_pagetables:0kB all_unreclaimable? no [13366.555184] Node 1 active_anon:100440kB inactive_anon:49404kB active_file:102108kB inactive_file:8744kB unevictable:0kB isolated(anon):0kB isolated(file):0kB mapped:50352kB dirty:8kB writeback:0kB shmem:33220kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 0kB writeback_tmp:0kB kernel_stack:3896kB pagetables:9052kB sec_pagetables:0kB all_unreclaimable? no [13366.558262] Node 0 DMA free:15360kB boost:0kB min:304kB low:380kB high:456kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:15992kB managed:15360kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB [13366.560821] lowmem_reserve[]: 0 2735 31873 31873 31873 [13366.561981] Node 0 DMA32 free:2790904kB boost:0kB min:56028kB low:70032kB high:84036kB reserved_highatomic:0KB active_anon:1936kB inactive_anon:20kB active_file:396kB inactive_file:344kB unevictable:0kB writepending:0kB present:3129200kB managed:2801520kB mlocked:0kB bounce:0kB free_pcp:5188kB local_pcp:0kB free_cma:0kB [13366.565148] lowmem_reserve[]: 0 0 29137 29137 29137 [13366.566168] Node 0 Normal free:28533824kB boost:0kB min:596740kB low:745924kB high:895108kB reserved_highatomic:28672KB active_anon:222900kB inactive_anon:33508kB active_file:175296kB inactive_file:13408kB unevictable:0kB writepending:32kB present:30408704kB managed:29837172kB mlocked:0kB bounce:0kB free_pcp:295724kB local_pcp:0kB free_cma:0kB [13366.569485] lowmem_reserve[]: 0 0 0 0 0 [13366.570416] Node 1 Normal free:32141144kB boost:0kB min:660504kB low:825628kB high:990752kB reserved_highatomic:69632KB active_anon:100440kB inactive_anon:49404kB active_file:102108kB inactive_file:8744kB unevictable:0kB writepending:8kB present:33554432kB managed:33025372kB mlocked:0kB bounce:0kB free_pcp:270880kB local_pcp:46860kB free_cma:0kB [13366.573403] lowmem_reserve[]: 0 0 0 0 0 [13366.574015] Node 0 DMA: 0*4kB 0*8kB 0*16kB 0*32kB 0*64kB 0*128kB 0*256kB 0*512kB 1*1024kB (U) 1*2048kB (M) 3*4096kB (M) = 15360kB [13366.575474] Node 0 DMA32: 782*4kB (UME) 756*8kB (UME) 736*16kB (UME) 745*32kB (UME) 694*64kB (UME) 653*128kB (UME) 595*256kB (UME) 552*512kB (UME) 454*1024kB (UME) 347*2048kB (UME) 246*4096kB (UME) = 2790904kB [13366.577442] Node 0 Normal: 33856*4kB (UMEH) 51815*8kB (UMEH) 42418*16kB (UMEH) 36272*32kB (UMEH) 22195*64kB (UMEH) 10296*128kB (UMEH) 7238*256kB (UMEH) 5638*512kB (UEH) 5337*1024kB (UMEH) 3506*2048kB (UMEH) 1470*4096kB (UME) = 28533784kB [13366.580460] Node 1 Normal: 15776*4kB (UMEH) 37485*8kB (UMEH) 29509*16kB (UMEH) 21420*32kB (UMEH) 14818*64kB (UMEH) 13051*128kB (UMEH) 9918*256kB (UMEH) 7374*512kB (UMEH) 5397*1024kB (UMEH) 3887*2048kB (UMEH) 2002*4096kB (UME) = 32141240kB [13366.583027] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB [13366.584380] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [13366.585702] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB [13366.587042] Node 1 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB [13366.588372] 87386 total pagecache pages [13366.589266] 0 pages in swap cache [13366.590327] Free swap = 0kB [13366.591227] Total swap = 0kB [13366.592142] 16777082 pages RAM [13366.593057] 0 pages HighMem/MovableOnly [13366.594037] 357226 pages reserved [13366.594979] 0 pages hwpoisoned This failure really confuse me as there're still lots of available pages. Finally I figured out it was caused by a fatal signal. When a process is allocating memory via vm_area_alloc_pages(), it will break directly even if it hasn't allocated the requested pages when it receives a fatal signal. In that case, we shouldn't show this warn_alloc, as it is useless. We only need to show this warning when there're really no enough pages. Link: https://lkml.kernel.org/r/20230330162625.13604-1-laoar.shao@gmail.com Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Lorenzo Stoakes
|
dcc1be1190 |
mm: prefer xxx_page() alloc/free functions for order-0 pages
Update instances of alloc_pages(..., 0), __get_free_pages(..., 0) and __free_pages(..., 0) to use alloc_page(), __get_free_page() and __free_page() respectively in core code. Link: https://lkml.kernel.org/r/50c48ca4789f1da2a65795f2346f5ae3eff7d665.1678710232.git.lstoakes@gmail.com Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Peter Collingbourne
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0a54864f8d |
kasan: remove PG_skip_kasan_poison flag
Code inspection reveals that PG_skip_kasan_poison is redundant with kasantag, because the former is intended to be set iff the latter is the match-all tag. It can also be observed that it's basically pointless to poison pages which have kasantag=0, because any pages with this tag would have been pointed to by pointers with match-all tags, so poisoning the pages would have little to no effect in terms of bug detection. Therefore, change the condition in should_skip_kasan_poison() to check kasantag instead, and remove PG_skip_kasan_poison and associated flags. Link: https://lkml.kernel.org/r/20230310042914.3805818-3-pcc@google.com Link: https://linux-review.googlesource.com/id/I57f825f2eaeaf7e8389d6cf4597c8a5821359838 Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Michal Hocko
|
e9c3cda4d8 |
mm, vmalloc: fix high order __GFP_NOFAIL allocations
Gao Xiang has reported that the page allocator complains about high order
__GFP_NOFAIL request coming from the vmalloc core:
__alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549
alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286
vm_area_alloc_pages mm/vmalloc.c:2989 [inline]
__vmalloc_area_node mm/vmalloc.c:3057 [inline]
__vmalloc_node_range+0x978/0x13c0 mm/vmalloc.c:3227
kvmalloc_node+0x156/0x1a0 mm/util.c:606
kvmalloc include/linux/slab.h:737 [inline]
kvmalloc_array include/linux/slab.h:755 [inline]
kvcalloc include/linux/slab.h:760 [inline]
it seems that I have completely missed high order allocation backing
vmalloc areas case when implementing __GFP_NOFAIL support. This means
that [k]vmalloc at al. can allocate higher order allocations with
__GFP_NOFAIL which can trigger OOM killer for non-costly orders easily or
cause a lot of reclaim/compaction activity if those requests cannot be
satisfied.
Fix the issue by falling back to zero order allocations for __GFP_NOFAIL
requests if the high order request fails.
Link: https://lkml.kernel.org/r/ZAXynvdNqcI0f6Us@dhcp22.suse.cz
Fixes:
|