Total patches: 36
Reviews/patch: 1.77
Reviewed rate: 83%
- The 2 patch series "mm/vmscan: fix demotion targets checks in
reclaim/demotion" from Bing Jiao fixes a couple of issues in the
demotion code - pages were failed demotion and were finding themselves
demoted into disallowed nodes.
- The 11 patch series "Remove XA_ZERO from error recovery of dup_mmap()"
from Liam Howlett fixes a rare mapledtree race and performs a number of
cleanups.
- The 13 patch series "mm: add bitmap VMA flag helpers and convert all
mmap_prepare to use them" from Lorenzo Stoakes implements a lot of
cleanups following on from the conversion of the VMA flags into a
bitmap.
- The 5 patch series "support batch checking of references and unmapping
for large folios" from Baolin Wang implements batching to greatly
improve the performance of reclaiming clean file-backed large folios.
- The 3 patch series "selftests/mm: add memory failure selftests" from
Miaohe Lin does as claimed.
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Merge tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a
couple of issues in the demotion code - pages were failed demotion
and were finding themselves demoted into disallowed nodes (Bing Jiao)
- "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare
mapledtree race and performs a number of cleanups (Liam Howlett)
- "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use
them" implements a lot of cleanups following on from the conversion
of the VMA flags into a bitmap (Lorenzo Stoakes)
- "support batch checking of references and unmapping for large folios"
implements batching to greatly improve the performance of reclaiming
clean file-backed large folios (Baolin Wang)
- "selftests/mm: add memory failure selftests" does as claimed (Miaohe
Lin)
* tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits)
mm/page_alloc: clear page->private in free_pages_prepare()
selftests/mm: add memory failure dirty pagecache test
selftests/mm: add memory failure clean pagecache test
selftests/mm: add memory failure anonymous page test
mm: rmap: support batched unmapping for file large folios
arm64: mm: implement the architecture-specific clear_flush_young_ptes()
arm64: mm: support batch clearing of the young flag for large folios
arm64: mm: factor out the address and ptep alignment into a new helper
mm: rmap: support batched checks of the references for large folios
tools/testing/vma: add VMA userland tests for VMA flag functions
tools/testing/vma: separate out vma_internal.h into logical headers
tools/testing/vma: separate VMA userland tests into separate files
mm: make vm_area_desc utilise vma_flags_t only
mm: update all remaining mmap_prepare users to use vma_flags_t
mm: update shmem_[kernel]_file_*() functions to use vma_flags_t
mm: update secretmem to use VMA flags on mmap_prepare
mm: update hugetlbfs to use VMA flags on mmap_prepare
mm: add basic VMA flag operation helper functions
tools: bitmap: add missing bitmap_[subset(), andnot()]
mm: add mk_vma_flags() bitmap flag macro helper
...
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Merge tag 'slab-for-7.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull more slab updates from Vlastimil Babka:
- Two stable fixes for kmalloc_nolock() usage from NMI context (Harry
Yoo)
- Allow kmalloc_nolock() allocations to be freed with kfree() and thus
also kfree_rcu() and simplify slabobj_ext handling - we no longer
need to track how it was allocated to use the matching freeing
function (Harry Yoo)
* tag 'slab-for-7.0-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
mm/slab: drop the OBJEXTS_NOSPIN_ALLOC flag from enum objext_flags
mm/slab: allow freeing kmalloc_nolock()'d objects using kfree[_rcu]()
mm/slab: use prandom if !allow_spin
mm/slab: do not access current->mems_allowed_seq if !allow_spin
Patch series "mm/vmscan: fix demotion targets checks in reclaim/demotion",
v9.
This patch series addresses two issues in demote_folio_list(),
can_demote(), and next_demotion_node() in reclaim/demotion.
1. demote_folio_list() and can_demote() do not correctly check
demotion target against cpuset.mems_effective, which will cause (a)
pages to be demoted to not-allowed nodes and (b) pages fail demotion
even if the system still has allowed demotion nodes.
Patch 1 fixes this bug by updating cpuset_node_allowed() and
mem_cgroup_node_allowed() to return effective_mems, allowing directly
logic-and operation against demotion targets.
2. next_demotion_node() returns a preferred demotion target, but it
does not check the node against allowed nodes.
Patch 2 ensures that next_demotion_node() filters against the allowed
node mask and selects the closest demotion target to the source node.
This patch (of 2):
Fix two bugs in demote_folio_list() and can_demote() due to incorrect
demotion target checks against cpuset.mems_effective in reclaim/demotion.
Commit 7d709f49ba ("vmscan,cgroup: apply mems_effective to reclaim")
introduces the cpuset.mems_effective check and applies it to can_demote().
However:
1. It does not apply this check in demote_folio_list(), which leads
to situations where pages are demoted to nodes that are
explicitly excluded from the task's cpuset.mems.
2. It checks only the nodes in the immediate next demotion hierarchy
and does not check all allowed demotion targets in can_demote().
This can cause pages to never be demoted if the nodes in the next
demotion hierarchy are not set in mems_effective.
These bugs break resource isolation provided by cpuset.mems. This is
visible from userspace because pages can either fail to be demoted
entirely or are demoted to nodes that are not allowed in multi-tier memory
systems.
To address these bugs, update cpuset_node_allowed() and
mem_cgroup_node_allowed() to return effective_mems, allowing directly
logic-and operation against demotion targets. Also update can_demote()
and demote_folio_list() accordingly.
Bug 1 reproduction:
Assume a system with 4 nodes, where nodes 0-1 are top-tier and
nodes 2-3 are far-tier memory. All nodes have equal capacity.
Test script:
echo 1 > /sys/kernel/mm/numa/demotion_enabled
mkdir /sys/fs/cgroup/test
echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control
echo "0-2" > /sys/fs/cgroup/test/cpuset.mems
echo $$ > /sys/fs/cgroup/test/cgroup.procs
swapoff -a
# Expectation: Should respect node 0-2 limit.
# Observation: Node 3 shows significant allocation (MemFree drops)
stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1
Bug 2 reproduction:
Assume a system with 6 nodes, where nodes 0-2 are top-tier,
node 3 is a far-tier node, and nodes 4-5 are the farthest-tier nodes.
All nodes have equal capacity.
Test script:
echo 1 > /sys/kernel/mm/numa/demotion_enabled
mkdir /sys/fs/cgroup/test
echo +cpuset > /sys/fs/cgroup/cgroup.subtree_control
echo "0-2,4-5" > /sys/fs/cgroup/test/cpuset.mems
echo $$ > /sys/fs/cgroup/test/cgroup.procs
swapoff -a
# Expectation: Pages are demoted to Nodes 4-5
# Observation: No pages are demoted before oom.
stress-ng --oomable --vm 1 --vm-bytes 150% --mbind 0,1,2
Link: https://lkml.kernel.org/r/20260114205305.2869796-1-bingjiao@google.com
Link: https://lkml.kernel.org/r/20260114205305.2869796-2-bingjiao@google.com
Fixes: 7d709f49ba ("vmscan,cgroup: apply mems_effective to reclaim")
Signed-off-by: Bing Jiao <bingjiao@google.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Gregory Price <gourry@gourry.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Everything:
Total patches: 325
Reviews/patch: 1.39
Reviewed rate: 72%
Excluding DAMON:
Total patches: 262
Reviews/patch: 1.63
Reviewed rate: 82%
Excluding DAMON and zram:
Total patches: 248
Reviews/patch: 1.72
Reviewed rate: 86%
- The 14 patch series "powerpc/64s: do not re-activate batched TLB
flush" from Alexander Gordeev makes arch_{enter|leave}_lazy_mmu_mode()
nest properly.
It adds a generic enter/leave layer and switches architectures to use
it. Various hacks were removed in the process.
- The 7 patch series "zram: introduce compressed data writeback" from
Richard Chang and Sergey Senozhatsky implements data compression for
zram writeback.
- The 8 patch series "mm: folio_zero_user: clear page ranges" from David
Hildenbrand adds clearing of contiguous page ranges for hugepages.
Large improvements during demand faulting are demonstrated.
- The 2 patch series "memcg cleanups" from Chen Ridong tideis up some
memcg code.
- The 12 patch series "mm/damon: introduce {,max_}nr_snapshots and
tracepoint for damos stats" from SeongJae Park improves DAMOS stat's
provided information, deterministic control, and readability.
- The 3 patch series "selftests/mm: hugetlb cgroup charging: robustness
fixes" from Li Wang fixes a few issues in the hugetlb cgroup charging
selftests.
- The 5 patch series "Fix va_high_addr_switch.sh test failure - again"
from Chunyu Hu addresses several issues in the va_high_addr_switch test.
- The 5 patch series "mm/damon/tests/core-kunit: extend existing test
scenarios" from Shu Anzai improves the KUnit test coverage for DAMON.
- The 2 patch series "mm/khugepaged: fix dirty page handling for
MADV_COLLAPSE" from Shivank Garg fixes a glitch in khugepaged which was
causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN.
- The 29 patch series "arch, mm: consolidate hugetlb early reservation"
from Mike Rapoport reworks and consolidates a pile of straggly code
related to reservation of hugetlb memory from bootmem and creation of
CMA areas for hugetlb.
- The 9 patch series "mm: clean up anon_vma implementation" from Lorenzo
Stoakes cleans up the anon_vma implementation in various ways.
- The 3 patch series "tweaks for __alloc_pages_slowpath()" from
Vlastimil Babka does a little streamlining of the page allocator's
slowpath code.
- The 8 patch series "memcg: separate private and public ID namespaces"
from Shakeel Butt cleans up the memcg ID code and prevents the
internal-only private IDs from being exposed to userspace.
- The 6 patch series "mm: hugetlb: allocate frozen gigantic folio" from
Kefeng Wang cleans up the allocation of frozen folios and avoids some
atomic refcount operations.
- The 11 patch series "mm/damon: advance DAMOS-based LRU sorting" from
SeongJae Park improves DAMOS's movement of memory betewwn the active and
inactive LRUs and adds auto-tuning of the ratio-based quotas and of
monitoring intervals.
- The 18 patch series "Support page table check on PowerPC" from Andrew
Donnellan makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc.
- The 3 patch series "nodemask: align nodes_and{,not} with underlying
bitmap ops" from Yury Norov makes nodes_and() and nodes_andnot()
propagate the return values from the underlying bit operations, enabling
some cleanup in calling code.
- The 5 patch series "mm/damon: hide kdamond and kdamond_lock from API
callers" from SeongJae Park cleans up some DAMON internal interfaces.
- The 4 patch series "mm/khugepaged: cleanups and scan limit fix" from
Shivank Garg does some cleanup work in khupaged and fixes a scan limit
accounting issue.
- The 24 patch series "mm: balloon infrastructure cleanups" from David
Hildenbrand goes to town on the balloon infrastructure and its page
migration function. Mainly cleanups, also some locking simplification.
- The 2 patch series "mm/vmscan: add tracepoint and reason for
kswapd_failures reset" from Jiayuan Chen adds additional tracepoints to
the page reclaim code.
- The 3 patch series "Replace wq users and add WQ_PERCPU to
alloc_workqueue() users" from Marco Crivellari is part of Marco's
kernel-wide migration from the legacy workqueue APIs over to the
preferred unbound workqueues.
- The 9 patch series "Various mm kselftests improvements/fixes" from
Kevin Brodsky provides various unrelated improvements/fixes for the mm
kselftests.
- The 5 patch series "mm: accelerate gigantic folio allocation" from
Kefeng Wang greatly speeds up gigantic folio allocation, mainly by
avoiding unnecessary work in pfn_range_valid_contig().
- The 5 patch series "selftests/damon: improve leak detection and wss
estimation reliability" from SeongJae Park improves the reliability of
two of the DAMON selftests.
- The 8 patch series "mm/damon: cleanup kdamond, damon_call(), damos
filter and DAMON_MIN_REGION" from SeongJae Park does some cleanup work
in the core DAMON code.
- The 8 patch series "Docs/mm/damon: update intro, modules, maintainer
profile, and misc" from SeongJae Park performs maintenance work on the
DAMON documentation.
- The 10 patch series "mm: add and use vma_assert_stabilised() helper"
from Lorenzo Stoakes refactors and cleans up the core VMA code. The
main aim here is to be able to use the mmap write lock's lockdep state
to perform various assertions regarding the locking which the VMA code
requires.
- The 19 patch series "mm, swap: swap table phase II: unify swapin use"
from Kairui Song removes some old swap code (swap cache bypassing and
swap synchronization) which wasn't working very well. Various other
cleanups and simplifications were made. The end result is a 20% speedup
in one benchmark.
- The 8 patch series "enable PT_RECLAIM on more 64-bit architectures"
from Qi Zheng makes PT_RECLAIM available on 64-bit alpha, loongarch,
mips, parisc, um, Various cleanups were performed along the way.
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Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "powerpc/64s: do not re-activate batched TLB flush" makes
arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)
It adds a generic enter/leave layer and switches architectures to use
it. Various hacks were removed in the process.
- "zram: introduce compressed data writeback" implements data
compression for zram writeback (Richard Chang and Sergey Senozhatsky)
- "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
page ranges for hugepages. Large improvements during demand faulting
are demonstrated (David Hildenbrand)
- "memcg cleanups" tidies up some memcg code (Chen Ridong)
- "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
stats" improves DAMOS stat's provided information, deterministic
control, and readability (SeongJae Park)
- "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
issues in the hugetlb cgroup charging selftests (Li Wang)
- "Fix va_high_addr_switch.sh test failure - again" addresses several
issues in the va_high_addr_switch test (Chunyu Hu)
- "mm/damon/tests/core-kunit: extend existing test scenarios" improves
the KUnit test coverage for DAMON (Shu Anzai)
- "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
transiently return -EAGAIN (Shivank Garg)
- "arch, mm: consolidate hugetlb early reservation" reworks and
consolidates a pile of straggly code related to reservation of
hugetlb memory from bootmem and creation of CMA areas for hugetlb
(Mike Rapoport)
- "mm: clean up anon_vma implementation" cleans up the anon_vma
implementation in various ways (Lorenzo Stoakes)
- "tweaks for __alloc_pages_slowpath()" does a little streamlining of
the page allocator's slowpath code (Vlastimil Babka)
- "memcg: separate private and public ID namespaces" cleans up the
memcg ID code and prevents the internal-only private IDs from being
exposed to userspace (Shakeel Butt)
- "mm: hugetlb: allocate frozen gigantic folio" cleans up the
allocation of frozen folios and avoids some atomic refcount
operations (Kefeng Wang)
- "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
of memory betewwn the active and inactive LRUs and adds auto-tuning
of the ratio-based quotas and of monitoring intervals (SeongJae Park)
- "Support page table check on PowerPC" makes
CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)
- "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
nodes_and() and nodes_andnot() propagate the return values from the
underlying bit operations, enabling some cleanup in calling code
(Yury Norov)
- "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
some DAMON internal interfaces (SeongJae Park)
- "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
in khupaged and fixes a scan limit accounting issue (Shivank Garg)
- "mm: balloon infrastructure cleanups" goes to town on the balloon
infrastructure and its page migration function. Mainly cleanups, also
some locking simplification (David Hildenbrand)
- "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
additional tracepoints to the page reclaim code (Jiayuan Chen)
- "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
part of Marco's kernel-wide migration from the legacy workqueue APIs
over to the preferred unbound workqueues (Marco Crivellari)
- "Various mm kselftests improvements/fixes" provides various unrelated
improvements/fixes for the mm kselftests (Kevin Brodsky)
- "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
folio allocation, mainly by avoiding unnecessary work in
pfn_range_valid_contig() (Kefeng Wang)
- "selftests/damon: improve leak detection and wss estimation
reliability" improves the reliability of two of the DAMON selftests
(SeongJae Park)
- "mm/damon: cleanup kdamond, damon_call(), damos filter and
DAMON_MIN_REGION" does some cleanup work in the core DAMON code
(SeongJae Park)
- "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
performs maintenance work on the DAMON documentation (SeongJae Park)
- "mm: add and use vma_assert_stabilised() helper" refactors and cleans
up the core VMA code. The main aim here is to be able to use the mmap
write lock's lockdep state to perform various assertions regarding
the locking which the VMA code requires (Lorenzo Stoakes)
- "mm, swap: swap table phase II: unify swapin use" removes some old
swap code (swap cache bypassing and swap synchronization) which
wasn't working very well. Various other cleanups and simplifications
were made. The end result is a 20% speedup in one benchmark (Kairui
Song)
- "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
available on 64-bit alpha, loongarch, mips, parisc, and um. Various
cleanups were performed along the way (Qi Zheng)
* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
mm/memory: handle non-split locks correctly in zap_empty_pte_table()
mm: move pte table reclaim code to memory.c
mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
um: mm: enable MMU_GATHER_RCU_TABLE_FREE
parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
zsmalloc: make common caches global
mm: add SPDX id lines to some mm source files
mm/zswap: use %pe to print error pointers
mm/vmscan: use %pe to print error pointers
mm/readahead: fix typo in comment
mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
mm: refactor vma_map_pages to use vm_insert_pages
mm/damon: unify address range representation with damon_addr_range
mm/cma: replace snprintf with strscpy in cma_new_area
...
- cpuset changes:
- Continue separating v1 and v2 implementations by moving more
v1-specific logic into cpuset-v1.c.
- Improve partition handling. Sibling partitions are no longer
invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
fail in v2, and effective_xcpus computation is made consistent.
- Fix partition effective CPUs overlap that caused a warning on cpuset
removal when sibling partitions shared CPUs.
- Increase the maximum cgroup subsystem count from 16 to 32 to
accommodate future subsystem additions.
- Misc cleanups and selftest improvements including switching to
css_is_online() helper, removing dead code and stale documentation
references, using lockdep_assert_cpuset_lock_held() consistently,
and adding polling helpers for asynchronously updated cgroup
statistics.
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Merge tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset changes:
- Continue separating v1 and v2 implementations by moving more
v1-specific logic into cpuset-v1.c
- Improve partition handling. Sibling partitions are no longer
invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
fail in v2, and effective_xcpus computation is made consistent
- Fix partition effective CPUs overlap that caused a warning on
cpuset removal when sibling partitions shared CPUs
- Increase the maximum cgroup subsystem count from 16 to 32 to
accommodate future subsystem additions
- Misc cleanups and selftest improvements including switching to
css_is_online() helper, removing dead code and stale documentation
references, using lockdep_assert_cpuset_lock_held() consistently, and
adding polling helpers for asynchronously updated cgroup statistics
* tag 'cgroup-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
cpuset: fix overlap of partition effective CPUs
cgroup: increase maximum subsystem count from 16 to 32
cgroup: Remove stale cpu.rt.max reference from documentation
cpuset: replace direct lockdep_assert_held() with lockdep_assert_cpuset_lock_held()
cgroup/cpuset: Move the v1 empty cpus/mems check to cpuset1_validate_change()
cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflict
cgroup/cpuset: Don't fail cpuset.cpus change in v2
cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier()
cgroup/cpuset: Streamline rm_siblings_excl_cpus()
cpuset: remove dead code in cpuset-v1.c
cpuset: remove v1-specific code from generate_sched_domains
cpuset: separate generate_sched_domains for v1 and v2
cpuset: move update_domain_attr_tree to cpuset_v1.c
cpuset: add cpuset1_init helper for v1 initialization
cpuset: add cpuset1_online_css helper for v1-specific operations
cpuset: add lockdep_assert_cpuset_lock_held helper
cpuset: Remove unnecessary checks in rebuild_sched_domains_locked
cgroup: switch to css_is_online() helper
selftests: cgroup: Replace sleep with cg_read_key_long_poll() for waiting on nr_dying_descendants
selftests: cgroup: make test_memcg_sock robust against delayed sock stats
...
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Merge tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov:
- Support associating BPF program with struct_ops (Amery Hung)
- Switch BPF local storage to rqspinlock and remove recursion detection
counters which were causing false positives (Amery Hung)
- Fix live registers marking for indirect jumps (Anton Protopopov)
- Introduce execution context detection BPF helpers (Changwoo Min)
- Improve verifier precision for 32bit sign extension pattern
(Cupertino Miranda)
- Optimize BTF type lookup by sorting vmlinux BTF and doing binary
search (Donglin Peng)
- Allow states pruning for misc/invalid slots in iterator loops (Eduard
Zingerman)
- In preparation for ASAN support in BPF arenas teach libbpf to move
global BPF variables to the end of the region and enable arena kfuncs
while holding locks (Emil Tsalapatis)
- Introduce support for implicit arguments in kfuncs and migrate a
number of them to new API. This is a prerequisite for cgroup
sub-schedulers in sched-ext (Ihor Solodrai)
- Fix incorrect copied_seq calculation in sockmap (Jiayuan Chen)
- Fix ORC stack unwind from kprobe_multi (Jiri Olsa)
- Speed up fentry attach by using single ftrace direct ops in BPF
trampolines (Jiri Olsa)
- Require frozen map for calculating map hash (KP Singh)
- Fix lock entry creation in TAS fallback in rqspinlock (Kumar
Kartikeya Dwivedi)
- Allow user space to select cpu in lookup/update operations on per-cpu
array and hash maps (Leon Hwang)
- Make kfuncs return trusted pointers by default (Matt Bobrowski)
- Introduce "fsession" support where single BPF program is executed
upon entry and exit from traced kernel function (Menglong Dong)
- Allow bpf_timer and bpf_wq use in all programs types (Mykyta
Yatsenko, Andrii Nakryiko, Kumar Kartikeya Dwivedi, Alexei
Starovoitov)
- Make KF_TRUSTED_ARGS the default for all kfuncs and clean up their
definition across the tree (Puranjay Mohan)
- Allow BPF arena calls from non-sleepable context (Puranjay Mohan)
- Improve register id comparison logic in the verifier and extend
linked registers with negative offsets (Puranjay Mohan)
- In preparation for BPF-OOM introduce kfuncs to access memcg events
(Roman Gushchin)
- Use CFI compatible destructor kfunc type (Sami Tolvanen)
- Add bitwise tracking for BPF_END in the verifier (Tianci Cao)
- Add range tracking for BPF_DIV and BPF_MOD in the verifier (Yazhou
Tang)
- Make BPF selftests work with 64k page size (Yonghong Song)
* tag 'bpf-next-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (268 commits)
selftests/bpf: Fix outdated test on storage->smap
selftests/bpf: Choose another percpu variable in bpf for btf_dump test
selftests/bpf: Remove test_task_storage_map_stress_lookup
selftests/bpf: Update task_local_storage/task_storage_nodeadlock test
selftests/bpf: Update task_local_storage/recursion test
selftests/bpf: Update sk_storage_omem_uncharge test
bpf: Switch to bpf_selem_unlink_nofail in bpf_local_storage_{map_free, destroy}
bpf: Support lockless unlink when freeing map or local storage
bpf: Prepare for bpf_selem_unlink_nofail()
bpf: Remove unused percpu counter from bpf_local_storage_map_free
bpf: Remove cgroup local storage percpu counter
bpf: Remove task local storage percpu counter
bpf: Change local_storage->lock and b->lock to rqspinlock
bpf: Convert bpf_selem_unlink to failable
bpf: Convert bpf_selem_link_map to failable
bpf: Convert bpf_selem_unlink_map to failable
bpf: Select bpf_local_storage_map_bucket based on bpf_local_storage
selftests/xsk: fix number of Tx frags in invalid packet
selftests/xsk: properly handle batch ending in the middle of a packet
bpf: Prevent reentrance into call_rcu_tasks_trace()
...
OBJEXTS_NOSPIN_ALLOC was used to remember whether a slabobj_ext vector
was allocated via kmalloc_nolock(), so that free_slab_obj_exts() could
call kfree_nolock() instead of kfree().
Now that kfree() supports freeing kmalloc_nolock() objects, this flag is
no longer needed. Instead, pass the allow_spin parameter down to
free_slab_obj_exts() to determine whether kfree_nolock() or kfree()
should be called in the free path, and free one bit in
enum objext_flags.
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Hao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260210044642.139482-3-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The HK_TYPE_DOMAIN housekeeping cpumask is now modifiable at runtime. In
order to synchronize against memcg workqueue to make sure that no
asynchronous draining is still pending or executing on a newly made
isolated CPU, the housekeeping susbsystem must flush the memcg
workqueues.
However the memcg workqueues can't be flushed easily since they are
queued to the main per-CPU workqueue pool.
Solve this with creating a memcg specific pool and provide and use the
appropriate flushing API.
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
Cc: linux-mm@kvack.org
Rename mem_cgroup_ino() to mem_cgroup_id() and mem_cgroup_get_from_ino()
to mem_cgroup_get_from_id(). These functions now use cgroup IDs (from
cgroup_id()) rather than inode numbers, so the names should reflect that.
[shakeel.butt@linux.dev: replace ino with id, per SeongJae]
Link: https://lkml.kernel.org/r/flkqanhyettp5uq22bjwg37rtmnpeg3mghznsylxcxxgaafpl4@nov2x7tagma7
[akpm@linux-foundation.org: build fix]
Link: https://lkml.kernel.org/r/20251225232116.294540-9-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Now that all callers have been converted to use either:
- The private ID APIs (mem_cgroup_private_id/mem_cgroup_from_private_id)
for internal kernel objects that outlive their cgroup
- The public cgroup ID APIs (mem_cgroup_ino/mem_cgroup_get_from_ino)
for external interfaces
Remove the unused wrapper functions mem_cgroup_id() and
mem_cgroup_from_id() along with their !CONFIG_MEMCG stubs.
Link: https://lkml.kernel.org/r/20251225232116.294540-8-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Switch mem_cgroup_ino() from using cgroup_ino() to cgroup_id(). The
cgroup_ino() returns the kernfs inode number while cgroup_id() returns the
kernfs node ID. For 64-bit systems, they are the same. Also
cgroup_get_from_id() expects 64-bit node ID which is called by
mem_cgroup_get_from_ino().
Change the type from unsigned long to u64 to match cgroup_id()'s return
type, and update the format specifiers accordingly.
Note that the names mem_cgroup_ino() and mem_cgroup_get_from_ino() are now
misnomers since they deal with cgroup IDs rather than inode numbers. A
follow-up patch will rename them.
Link: https://lkml.kernel.org/r/20251225232116.294540-5-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Remove the CONFIG_SHRINKER_DEBUG guards around mem_cgroup_ino() and
mem_cgroup_get_from_ino(). These APIs provide a way to get a memcg's
cgroup inode number and to look up a memcg from an inode number
respectively.
Making these functions unconditionally available allows other in-kernel
users to leverage them without requiring CONFIG_SHRINKER_DEBUG to be
enabled.
No functional change for existing users.
Link: https://lkml.kernel.org/r/20251225232116.294540-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "memcg: separate private and public ID namespaces".
The memory cgroup subsystem maintains a private ID infrastructure that
is decoupled from the cgroup IDs. This private ID system exists because
some kernel objects (like swap entries and shadow entries in the
workingset code) can outlive the cgroup they were associated with.
The motivation is best described in commit 73f576c04b ("mm:
memcontrol: fix cgroup creation failure after many small jobs").
Unfortunately, some in-kernel users (DAMON, LRU gen debugfs interface,
shrinker debugfs) started exposing these private IDs to userspace.
This is problematic because:
1. The private IDs are internal implementation details that could change
2. Userspace already has access to cgroup IDs through the cgroup
filesystem
3. Using different ID namespaces in different interfaces is confusing
This series cleans up the memcg ID infrastructure by:
1. Explicitly marking the private ID APIs with "private" in their names
to make it clear they are for internal use only (swap/workingset)
2. Making the public cgroup ID APIs (mem_cgroup_id/mem_cgroup_get_from_id)
unconditionally available
3. Converting DAMON, LRU gen, and shrinker debugfs interfaces to use
the public cgroup IDs instead of the private IDs
4. Removing the now-unused wrapper functions and renaming the public
APIs for clarity
After this series:
- mem_cgroup_private_id() / mem_cgroup_from_private_id() are used for
internal kernel objects that outlive their cgroup (swap, workingset)
- mem_cgroup_id() / mem_cgroup_get_from_id() return the public cgroup ID
(from cgroup_id()) for use in userspace-facing interfaces
This patch (of 8):
The memory cgroup maintains a private ID infrastructure decoupled from the
cgroup IDs for swapout records and shadow entries. The main motivation of
this private ID infra is best described in the commit 73f576c04b ("mm:
memcontrol: fix cgroup creation failure after many small jobs").
Unfortunately some users have started exposing these private IDs to the
userspace where they should have used the cgroup IDs which are already
exposed to the userspace. Let's rename the memcg ID APIs to explicitly
mark them private.
No functional change is intended.
Link: https://lkml.kernel.org/r/20251225232116.294540-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20251225232116.294540-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In addition to slab objects, this function is used for resolving non-slab
kernel pointers. This has caused confusion in recent refactoring work.
Rename it to mem_cgroup_from_virt(), sticking with terminology established
by the virt_to_<foo>() converters.
Link: https://lore.kernel.org/linux-mm/20251113161424.GB3465062@cmpxchg.org/
Link: https://lkml.kernel.org/r/20251210154301.720133-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The mem_cgroup_size helper is used only in apply_proportional_protection
to read the current memory usage. Its semantics are unclear and
inconsistent with other sites, which directly call page_counter_read for
the same purpose.
Remove this helper and get its usage via mem_cgroup_protection for
clarity. Additionally, rename the local variable 'cgroup_size' to 'usage'
to better reflect its meaning.
No functional changes intended.
Link: https://lkml.kernel.org/r/20251211013019.2080004-3-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lu Jialin <lujialin4@huawei.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Introduce BPF kfuncs to conveniently access memcg data:
- bpf_mem_cgroup_vm_events(),
- bpf_mem_cgroup_memory_events(),
- bpf_mem_cgroup_usage(),
- bpf_mem_cgroup_page_state(),
- bpf_mem_cgroup_flush_stats().
These functions are useful for implementing BPF OOM policies, but
also can be used to accelerate access to the memcg data. Reading
it through cgroupfs is much more expensive, roughly 5x, mostly
because of the need to convert the data into the text and back.
JP Kobryn:
An experiment was setup to compare the performance of a program that
uses the traditional method of reading memory.stat vs a program using
the new kfuncs. The control program opens up the root memory.stat file
and for 1M iterations reads, converts the string values to numeric data,
then seeks back to the beginning. The experimental program sets up the
requisite libbpf objects and for 1M iterations invokes a bpf program
which uses the kfuncs to fetch all available stats for node_stat_item,
memcg_stat_item, and vm_event_item types.
The results showed a significant perf benefit on the experimental side,
outperforming the control side by a margin of 93%. In kernel mode,
elapsed time was reduced by 80%, while in user mode, over 99% of time
was saved.
control: elapsed time
real 0m38.318s
user 0m25.131s
sys 0m13.070s
experiment: elapsed time
real 0m2.789s
user 0m0.187s
sys 0m2.512s
control: perf data
33.43% a.out libc.so.6 [.] __vfscanf_internal
6.88% a.out [kernel.kallsyms] [k] vsnprintf
6.33% a.out libc.so.6 [.] _IO_fgets
5.51% a.out [kernel.kallsyms] [k] format_decode
4.31% a.out libc.so.6 [.] __GI_____strtoull_l_internal
3.78% a.out [kernel.kallsyms] [k] string
3.53% a.out [kernel.kallsyms] [k] number
2.71% a.out libc.so.6 [.] _IO_sputbackc
2.41% a.out [kernel.kallsyms] [k] strlen
1.98% a.out a.out [.] main
1.70% a.out libc.so.6 [.] _IO_getline_info
1.51% a.out libc.so.6 [.] __isoc99_sscanf
1.47% a.out [kernel.kallsyms] [k] memory_stat_format
1.47% a.out [kernel.kallsyms] [k] memcpy_orig
1.41% a.out [kernel.kallsyms] [k] seq_buf_printf
experiment: perf data
10.55% memcgstat bpf_prog_..._query [k] bpf_prog_16aab2f19fa982a7_query
6.90% memcgstat [kernel.kallsyms] [k] memcg_page_state_output
3.55% memcgstat [kernel.kallsyms] [k] _raw_spin_lock
3.12% memcgstat [kernel.kallsyms] [k] memcg_events
2.87% memcgstat [kernel.kallsyms] [k] __memcg_slab_post_alloc_hook
2.73% memcgstat [kernel.kallsyms] [k] kmem_cache_free
2.70% memcgstat [kernel.kallsyms] [k] entry_SYSRETQ_unsafe_stack
2.25% memcgstat [kernel.kallsyms] [k] __memcg_slab_free_hook
2.06% memcgstat [kernel.kallsyms] [k] get_page_from_freelist
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Co-developed-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Link: https://lore.kernel.org/r/20251223044156.208250-5-roman.gushchin@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
To use memcg_page_state_output() in bpf_memcontrol.c move the
declaration from v1-specific memcontrol-v1.h to memcontrol.h.
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://lore.kernel.org/r/20251223044156.208250-2-roman.gushchin@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Use the new css_is_online() helper that has been introduced to check css
online state, instead of testing the CSS_ONLINE flag directly. This
improves readability and centralizes the state check logic.
No functional changes intended.
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
The dec_lruvec_kmem_state helper is unused by any caller and can be safely
removed. Meanwhile, the inc_lruvec_kmem_state helper is only referenced
by shadow_lru_isolate, retaining these two helpers is unnecessary. This
patch removes both helper functions to eliminate redundant code.
Link: https://lkml.kernel.org/r/20251126020435.1511637-1-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Lu Jialin <lujialin4@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__mod_lruvec_kmem_state() is already safe against irqs, so there is no
need to have a separate interface (i.e. mod_lruvec_kmem_state) which
wraps calls to it with irq disabling and reenabling. Let's rename
__mod_lruvec_kmem_state() to mod_lruvec_kmem_state().
Link: https://lkml.kernel.org/r/20251110232008.1352063-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "memcg: cleanup the memcg stats interfaces".
The memcg stats are safe against irq (and nmi) context and thus does not
require disabling irqs. However for some stats which are also maintained
at node level, it is using irq unsafe interface and thus requiring the
users to still disables irqs or use interfaces which explicitly disables
irqs. Let's move memcg code to use irq safe node level stats function
which is already optimized for architectures with HAVE_CMPXCHG_LOCAL (all
major ones), so there will not be any performance penalty for its usage.
This patch (of 4):
The memcg stats are safe against irq (and nmi) context and thus does not
require disabling irqs. However some code paths for memcg stats also
update the node level stats and use irq unsafe interface and thus require
the users to disable irqs. However node level stats, on architectures
with HAVE_CMPXCHG_LOCAL (all major ones), has interface which does not
require irq disabling. Let's move memcg stats code to start using that
interface for node level stats.
Link: https://lkml.kernel.org/r/20251110232008.1352063-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20251110232008.1352063-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Similar to list_lru, the split queue is relatively independent and does
not need to be reparented along with objcg and LRU folios (holding objcg
lock and lru lock). So let's apply the similar mechanism as list_lru to
reparent the split queue separately when memcg is offine.
This is also a preparation for reparenting LRU folios.
Link: https://lkml.kernel.org/r/8703f907c4d1f7e8a2ef2bfed3036a84fa53028b.1762762324.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In future memcg removal, the binding between a folio and a memcg may
change, making the split lock within the memcg unstable when held.
A new approach is required to reparent the split queue to its parent.
This patch starts introducing a unified way to acquire the split lock for
future work.
It's a code-only refactoring with no functional changes.
Link: https://lkml.kernel.org/r/a31a90bcac04dc754f775e87ae3205be3170b571.1762762324.git.zhengqi.arch@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Currently kernel dumps memory state on oom and allocation failures. One
of the question usually raised on those dumps is why the kernel has not
reclaimed the reclaimable memory instead of triggering oom. One potential
reason is the usage of memory protection provided by memcg. So, let's
also dump the memory protected by the memcg in such reports to ease the
debugging.
Link: https://lkml.kernel.org/r/20251107234041.3632644-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
__memcg_memory_event() has been unnecessarily marked inline even when it
is not really performance critical. It is usually called to track extreme
conditions. Over the time, it has evolved to include more functionality
and inlining it is causing more harm.
Before the patch:
$ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o
text data bss dec hex filename
35645 10574 4192 50411 c4eb mm/memcontrol.o
54738 1658 0 56396 dc4c net/ipv4/tcp_input.o
34644 1065 0 35709 8b7d net/ipv4/tcp_output.o
After the patch:
$ size mm/memcontrol.o net/ipv4/tcp_input.o net/ipv4/tcp_output.o
text data bss dec hex filename
35137 10446 4192 49775 c26f mm/memcontrol.o
54322 1562 0 55884 da4c net/ipv4/tcp_input.o
34492 1017 0 35509 8ab5 net/ipv4/tcp_output.o
[akpm@linux-foundation.org: use EXPORT_SYMBOL_GPL for __memcg_memory_event, per Michal and Christoph]
Link: https://lkml.kernel.org/r/20251021234425.1885471-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: SeongJae Park <sj@kernel.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The kernel can throttle network sockets if the memory cgroup associated
with the corresponding socket is under memory pressure. The throttling
actions include clamping the transmit window, failing to expand receive or
send buffers, aggressively prune out-of-order receive queue, FIN deferred
to a retransmitted packet and more. Let's add memcg metric to track such
throttling actions.
At the moment memcg memory pressure is defined through vmpressure and in
future it may be defined using PSI or we may add more flexible way for the
users to define memory pressure, maybe through ebpf. However the
potential throttling actions will remain the same, so this newly
introduced metric will continue to track throttling actions irrespective
of how memcg memory pressure is defined.
Link: https://lkml.kernel.org/r/20251016161035.86161-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Daniel Sedlak <daniel.sedlak@cdn77.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kacinski <kuba@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Generally memcg charging is allowed from all the contexts including NMI
where even spinning on spinlock can cause locking issues. However one
call chain was missed during the addition of memcg charging from any
context support. That is try_charge_memcg() -> memcg_memory_event() ->
cgroup_file_notify().
The possible function call tree under cgroup_file_notify() can acquire
many different spin locks in spinning mode. Some of them are
cgroup_file_kn_lock, kernfs_notify_lock, pool_workqeue's lock. So, let's
just skip cgroup_file_notify() from memcg charging if the context does not
allow spinning.
Alternative approach was also explored where instead of skipping
cgroup_file_notify(), we defer the memcg event processing to irq_work [1].
However it adds complexity and it was decided to keep things simple until
we need more memcg events with !allow_spinning requirement.
Link: https://lore.kernel.org/all/5qi2llyzf7gklncflo6gxoozljbm4h3tpnuv4u4ej4ztysvi6f@x44v7nz2wdzd/ [1]
Link: https://lkml.kernel.org/r/20250922220203.261714-1-shakeel.butt@linux.dev
Fixes: 3ac4638a73 ("memcg: make memcg_rstat_updated nmi safe")
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Closes: https://lore.kernel.org/all/20250905061919.439648-1-yepeilin@google.com/
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peilin Ye <yepeilin@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- The 3 patch series "mm, swap: improve cluster scan strategy" from
Kairui Song improves performance and reduces the failure rate of swap
cluster allocation.
- The 4 patch series "support large align and nid in Rust allocators"
from Vitaly Wool permits Rust allocators to set NUMA node and large
alignment when perforning slub and vmalloc reallocs.
- The 2 patch series "mm/damon/vaddr: support stat-purpose DAMOS" from
Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets
for virtual address spaces for ops-level DAMOS filters.
- The 3 patch series "execute PROCMAP_QUERY ioctl under per-vma lock"
from Suren Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps.
- The 2 patch series "mm/mincore: minor clean up for swap cache
checking" from Kairui Song performs some cleanup in the swap code.
- The 11 patch series "mm: vm_normal_page*() improvements" from David
Hildenbrand provides code cleanup in the pagemap code.
- The 5 patch series "add persistent huge zero folio support" from
Pankaj Raghav provides a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero.
- The 3 patch series "kho: fixes and cleanups" from Mike Rapoport adds a
few touchups to the recently added Kexec Handover feature.
- The 10 patch series "mm: make mm->flags a bitmap and 64-bit on all
arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To
end the constant struggle with space shortage on 32-bit conflicting with
64-bit's needs.
- The 2 patch series "mm/swapfile.c and swap.h cleanup" from Chris Li
cleans up some swap code.
- The 7 patch series "selftests/mm: Fix false positives and skip
unsupported tests" from Donet Tom fixes a few things in our selftests
code.
- The 7 patch series "prctl: extend PR_SET_THP_DISABLE to only provide
THPs when advised" from David Hildenbrand "allows individual processes
to opt-out of THP=always into THP=madvise, without affecting other
workloads on the system".
It's a long story - the [1/N] changelog spells out the considerations.
- The 11 patch series "Add and use memdesc_flags_t" from Matthew Wilcox
gets us started on the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc.
- The 3 patch series "Tiny optimization for large read operations" from
Chi Zhiling improves the efficiency of the pagecache read path.
- The 5 patch series "Better split_huge_page_test result check" from Zi
Yan improves our folio splitting selftest code.
- The 2 patch series "test that rmap behaves as expected" from Wei Yang
adds some rmap selftests.
- The 3 patch series "remove write_cache_pages()" from Christoph Hellwig
removes that function and converts its two remaining callers.
- The 2 patch series "selftests/mm: uffd-stress fixes" from Dev Jain
fixes some UFFD selftests issues.
- The 3 patch series "introduce kernel file mapped folios" from Boris
Burkov introduces the concept of "kernel file pages". Using these
permits btrfs to account its metadata pages to the root cgroup, rather
than to the cgroups of random inappropriate tasks.
- The 2 patch series "mm/pageblock: improve readability of some
pageblock handling" from Wei Yang provides some readability improvements
to the page allocator code.
- The 11 patch series "mm/damon: support ARM32 with LPAE" from SeongJae
Park teaches DAMON to understand arm32 highmem.
- The 4 patch series "tools: testing: Use existing atomic.h for
vma/maple tests" from Brendan Jackman performs some code cleanups and
deduplication under tools/testing/.
- The 2 patch series "maple_tree: Fix testing for 32bit compiles" from
Liam Howlett fixes a couple of 32-bit issues in
tools/testing/radix-tree.c.
- The 2 patch series "kasan: unify kasan_enabled() and remove
arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN
arch-specific initialization code into a common arch-neutral
implementation.
- The 3 patch series "mm: remove zpool" from Johannes Weiner removes
zspool - an indirection layer which now only redirects to a single thing
(zsmalloc).
- The 2 patch series "mm: task_stack: Stack handling cleanups" from
Pasha Tatashin makes a couple of cleanups in the fork code.
- The 37 patch series "mm: remove nth_page()" from David Hildenbrand
makes rather a lot of adjustments at various nth_page() callsites,
eventually permitting the removal of that undesirable helper function.
- The 2 patch series "introduce kasan.write_only option in hw-tags" from
Yeoreum Yun creates a KASAN read-only mode for ARM, using that
architecture's memory tagging feature. It is felt that a read-only mode
KASAN is suitable for use in production systems rather than debug-only.
- The 3 patch series "mm: hugetlb: cleanup hugetlb folio allocation"
from Kefeng Wang does some tidying in the hugetlb folio allocation code.
- The 12 patch series "mm: establish const-correctness for pointer
parameters" from Max Kellermann makes quite a number of the MM API
functions more accurate about the constness of their arguments. This
was getting in the way of subsystems (in this case CEPH) when they
attempt to improving their own const/non-const accuracy.
- The 7 patch series "Cleanup free_pages() misuse" from Vishal Moola
fixes a number of code sites which were confused over when to use
free_pages() vs __free_pages().
- The 3 patch series "Add Rust abstraction for Maple Trees" from Alice
Ryhl makes the mapletree code accessible to Rust. Required by nouveau
and by its forthcoming successor: the new Rust Nova driver.
- The 2 patch series "selftests/mm: split_huge_page_test:
split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and
some cleanups to the thp selftesting code.
- The 14 patch series "mm, swap: introduce swap table as swap cache
(phase I)" from Chris Li and Kairui Song is the first step along the
path to implementing "swap tables" - a new approach to swap allocation
and state tracking which is expected to yield speed and space
improvements. This patchset itself yields a 5-20% performance benefit
in some situations.
- The 3 patch series "Some ptdesc cleanups" from Matthew Wilcox utilizes
the new memdesc layer to clean up the ptdesc code a little.
- The 3 patch series "Fix va_high_addr_switch.sh test failure" from
Chunyu Hu fixes some issues in our 5-level pagetable selftesting code.
- The 2 patch series "Minor fixes for memory allocation profiling" from
Suren Baghdasaryan addresses a couple of minor issues in relatively new
memory allocation profiling feature.
- The 3 patch series "Small cleanups" from Matthew Wilcox has a few
cleanups in preparation for more memdesc work.
- The 2 patch series "mm/damon: add addr_unit for DAMON_LRU_SORT and
DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in
furtherance of supporting arm highmem.
- The 2 patch series "selftests/mm: Add -Wunreachable-code and fix
warnings" from Muhammad Anjum adds that compiler check to selftests code
and fixes the fallout, by removing dead code.
- The 10 patch series "Improvements to Victim Process Thawing and OOM
Reaper Traversal Order" from zhongjinji makes a number of improvements
in the OOM killer: mainly thawing a more appropriate group of victim
threads so they can release resources.
- The 5 patch series "mm/damon: misc fixups and improvements for 6.18"
from SeongJae Park is a bunch of small and unrelated fixups for DAMON.
- The 7 patch series "mm/damon: define and use DAMON initialization
check function" from SeongJae Park implement reliability and
maintainability improvements to a recently-added bug fix.
- The 2 patch series "mm/damon/stat: expose auto-tuned intervals and
non-idle ages" from SeongJae Park provides additional transparency to
userspace clients of the DAMON_STAT information.
- The 2 patch series "Expand scope of khugepaged anonymous collapse"
from Dev Jain removes some constraints on khubepaged's collapsing of
anon VMAs. It also increases the success rate of MADV_COLLAPSE against
an anon vma.
- The 2 patch series "mm: do not assume file == vma->vm_file in
compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards
removal of file_operations.mmap(). This patchset concentrates upon
clearing up the treatment of stacked filesystems.
- The 6 patch series "mm: Improve mlock tracking for large folios" from
Kiryl Shutsemau provides some fixes and improvements to mlock's tracking
of large folios. /proc/meminfo's "Mlocked" field became more accurate.
- The 2 patch series "mm/ksm: Fix incorrect accounting of KSM counters
during fork" from Donet Tom fixes several user-visible KSM stats
inaccuracies across forks and adds selftest code to verify these
counters.
- The 2 patch series "mm_slot: fix the usage of mm_slot_entry" from Wei
Yang addresses some potential but presently benign issues in KSM's
mm_slot handling.
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Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm, swap: improve cluster scan strategy" from Kairui Song improves
performance and reduces the failure rate of swap cluster allocation
- "support large align and nid in Rust allocators" from Vitaly Wool
permits Rust allocators to set NUMA node and large alignment when
perforning slub and vmalloc reallocs
- "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend
DAMOS_STAT's handling of the DAMON operations sets for virtual
address spaces for ops-level DAMOS filters
- "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren
Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps
- "mm/mincore: minor clean up for swap cache checking" from Kairui Song
performs some cleanup in the swap code
- "mm: vm_normal_page*() improvements" from David Hildenbrand provides
code cleanup in the pagemap code
- "add persistent huge zero folio support" from Pankaj Raghav provides
a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero
- "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to
the recently added Kexec Handover feature
- "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo
Stoakes turns mm_struct.flags into a bitmap. To end the constant
struggle with space shortage on 32-bit conflicting with 64-bit's
needs
- "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap
code
- "selftests/mm: Fix false positives and skip unsupported tests" from
Donet Tom fixes a few things in our selftests code
- "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised"
from David Hildenbrand "allows individual processes to opt-out of
THP=always into THP=madvise, without affecting other workloads on the
system".
It's a long story - the [1/N] changelog spells out the considerations
- "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on
the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc
- "Tiny optimization for large read operations" from Chi Zhiling
improves the efficiency of the pagecache read path
- "Better split_huge_page_test result check" from Zi Yan improves our
folio splitting selftest code
- "test that rmap behaves as expected" from Wei Yang adds some rmap
selftests
- "remove write_cache_pages()" from Christoph Hellwig removes that
function and converts its two remaining callers
- "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD
selftests issues
- "introduce kernel file mapped folios" from Boris Burkov introduces
the concept of "kernel file pages". Using these permits btrfs to
account its metadata pages to the root cgroup, rather than to the
cgroups of random inappropriate tasks
- "mm/pageblock: improve readability of some pageblock handling" from
Wei Yang provides some readability improvements to the page allocator
code
- "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON
to understand arm32 highmem
- "tools: testing: Use existing atomic.h for vma/maple tests" from
Brendan Jackman performs some code cleanups and deduplication under
tools/testing/
- "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes
a couple of 32-bit issues in tools/testing/radix-tree.c
- "kasan: unify kasan_enabled() and remove arch-specific
implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific
initialization code into a common arch-neutral implementation
- "mm: remove zpool" from Johannes Weiner removes zspool - an
indirection layer which now only redirects to a single thing
(zsmalloc)
- "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a
couple of cleanups in the fork code
- "mm: remove nth_page()" from David Hildenbrand makes rather a lot of
adjustments at various nth_page() callsites, eventually permitting
the removal of that undesirable helper function
- "introduce kasan.write_only option in hw-tags" from Yeoreum Yun
creates a KASAN read-only mode for ARM, using that architecture's
memory tagging feature. It is felt that a read-only mode KASAN is
suitable for use in production systems rather than debug-only
- "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does
some tidying in the hugetlb folio allocation code
- "mm: establish const-correctness for pointer parameters" from Max
Kellermann makes quite a number of the MM API functions more accurate
about the constness of their arguments. This was getting in the way
of subsystems (in this case CEPH) when they attempt to improving
their own const/non-const accuracy
- "Cleanup free_pages() misuse" from Vishal Moola fixes a number of
code sites which were confused over when to use free_pages() vs
__free_pages()
- "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the
mapletree code accessible to Rust. Required by nouveau and by its
forthcoming successor: the new Rust Nova driver
- "selftests/mm: split_huge_page_test: split_pte_mapped_thp
improvements" from David Hildenbrand adds a fix and some cleanups to
the thp selftesting code
- "mm, swap: introduce swap table as swap cache (phase I)" from Chris
Li and Kairui Song is the first step along the path to implementing
"swap tables" - a new approach to swap allocation and state tracking
which is expected to yield speed and space improvements. This
patchset itself yields a 5-20% performance benefit in some situations
- "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc
layer to clean up the ptdesc code a little
- "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some
issues in our 5-level pagetable selftesting code
- "Minor fixes for memory allocation profiling" from Suren Baghdasaryan
addresses a couple of minor issues in relatively new memory
allocation profiling feature
- "Small cleanups" from Matthew Wilcox has a few cleanups in
preparation for more memdesc work
- "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from
Quanmin Yan makes some changes to DAMON in furtherance of supporting
arm highmem
- "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad
Anjum adds that compiler check to selftests code and fixes the
fallout, by removing dead code
- "Improvements to Victim Process Thawing and OOM Reaper Traversal
Order" from zhongjinji makes a number of improvements in the OOM
killer: mainly thawing a more appropriate group of victim threads so
they can release resources
- "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park
is a bunch of small and unrelated fixups for DAMON
- "mm/damon: define and use DAMON initialization check function" from
SeongJae Park implement reliability and maintainability improvements
to a recently-added bug fix
- "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from
SeongJae Park provides additional transparency to userspace clients
of the DAMON_STAT information
- "Expand scope of khugepaged anonymous collapse" from Dev Jain removes
some constraints on khubepaged's collapsing of anon VMAs. It also
increases the success rate of MADV_COLLAPSE against an anon vma
- "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()"
from Lorenzo Stoakes moves us further towards removal of
file_operations.mmap(). This patchset concentrates upon clearing up
the treatment of stacked filesystems
- "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau
provides some fixes and improvements to mlock's tracking of large
folios. /proc/meminfo's "Mlocked" field became more accurate
- "mm/ksm: Fix incorrect accounting of KSM counters during fork" from
Donet Tom fixes several user-visible KSM stats inaccuracies across
forks and adds selftest code to verify these counters
- "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses
some potential but presently benign issues in KSM's mm_slot handling
* tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits)
mm: swap: check for stable address space before operating on the VMA
mm: convert folio_page() back to a macro
mm/khugepaged: use start_addr/addr for improved readability
hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list
alloc_tag: fix boot failure due to NULL pointer dereference
mm: silence data-race in update_hiwater_rss
mm/memory-failure: don't select MEMORY_ISOLATION
mm/khugepaged: remove definition of struct khugepaged_mm_slot
mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
hugetlb: increase number of reserving hugepages via cmdline
selftests/mm: add fork inheritance test for ksm_merging_pages counter
mm/ksm: fix incorrect KSM counter handling in mm_struct during fork
drivers/base/node: fix double free in register_one_node()
mm: remove PMD alignment constraint in execmem_vmalloc()
mm/memory_hotplug: fix typo 'esecially' -> 'especially'
mm/rmap: improve mlock tracking for large folios
mm/filemap: map entire large folio faultaround
mm/fault: try to map the entire file folio in finish_fault()
mm/rmap: mlock large folios in try_to_unmap_one()
mm/rmap: fix a mlock race condition in folio_referenced_one()
...
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Merge tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- A new layer for caching objects for allocation and free via percpu
arrays called sheaves.
The aim is to combine the good parts of SLAB (lower-overhead and
simpler percpu caching, compared to SLUB) without the past issues
with arrays for freeing remote NUMA node objects and their flushing.
It also allows more efficient kfree_rcu(), and cheaper object
preallocations for cases where the exact number of objects is
unknown, but an upper bound is.
Currently VMAs and maple nodes are using this new caching, with a
plan to enable it for all caches and remove the complex SLUB fastpath
based on cpu (partial) slabs and this_cpu_cmpxchg_double().
(Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple
tree changes)
- Re-entrant kmalloc_nolock(), which allows opportunistic allocations
from NMI and tracing/kprobe contexts.
Building on prior page allocator and memcg changes, it will result in
removing BPF-specific caches on top of slab (Alexei Starovoitov)
- Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren
Baghdasaryan, Ye Liu)
* tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits)
slab: Introduce kmalloc_nolock() and kfree_nolock().
slab: Reuse first bit for OBJEXTS_ALLOC_FAIL
slab: Make slub local_(try)lock more precise for LOCKDEP
mm: Introduce alloc_frozen_pages_nolock()
mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock().
locking/local_lock: Introduce local_lock_is_locked().
maple_tree: Convert forking to use the sheaf interface
maple_tree: Add single node allocation support to maple state
maple_tree: Prefilled sheaf conversion and testing
tools/testing: Add support for prefilled slab sheafs
maple_tree: Replace mt_free_one() with kfree()
maple_tree: Use kfree_rcu in ma_free_rcu
testing/radix-tree/maple: Hack around kfree_rcu not existing
tools/testing: include maple-shim.c in maple.c
maple_tree: use percpu sheaves for maple_node_cache
mm, vma: use percpu sheaves for vm_area_struct cache
tools/testing: Add support for changes to slab for sheaves
slab: allow NUMA restricted allocations to use percpu sheaves
tools/testing/vma: Implement vm_refcnt reset
slab: skip percpu sheaves for remote object freeing
...
kmalloc_nolock() relies on ability of local_trylock_t to detect
the situation when per-cpu kmem_cache is locked.
In !PREEMPT_RT local_(try)lock_irqsave(&s->cpu_slab->lock, flags)
disables IRQs and marks s->cpu_slab->lock as acquired.
local_lock_is_locked(&s->cpu_slab->lock) returns true when
slab is in the middle of manipulating per-cpu cache
of that specific kmem_cache.
kmalloc_nolock() can be called from any context and can re-enter
into ___slab_alloc():
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> NMI -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
or
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> tracepoint/kprobe -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
Hence the caller of ___slab_alloc() checks if &s->cpu_slab->lock
can be acquired without a deadlock before invoking the function.
If that specific per-cpu kmem_cache is busy the kmalloc_nolock()
retries in a different kmalloc bucket. The second attempt will
likely succeed, since this cpu locked different kmem_cache.
Similarly, in PREEMPT_RT local_lock_is_locked() returns true when
per-cpu rt_spin_lock is locked by current _task_. In this case
re-entrance into the same kmalloc bucket is unsafe, and
kmalloc_nolock() tries a different bucket that is most likely is
not locked by the current task. Though it may be locked by a
different task it's safe to rt_spin_lock() and sleep on it.
Similar to alloc_pages_nolock() the kmalloc_nolock() returns NULL
immediately if called from hard irq or NMI in PREEMPT_RT.
kfree_nolock() defers freeing to irq_work when local_lock_is_locked()
and (in_nmi() or in PREEMPT_RT).
SLUB_TINY config doesn't use local_lock_is_locked() and relies on
spin_trylock_irqsave(&n->list_lock) to allocate,
while kfree_nolock() always defers to irq_work.
Note, kfree_nolock() must be called _only_ for objects allocated
with kmalloc_nolock(). Debug checks (like kmemleak and kfence)
were skipped on allocation, hence obj = kmalloc(); kfree_nolock(obj);
will miss kmemleak/kfence book keeping and will cause false positives.
large_kmalloc is not supported by either kmalloc_nolock()
or kfree_nolock().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Since the combination of valid upper bits in slab->obj_exts with
OBJEXTS_ALLOC_FAIL bit can never happen,
use OBJEXTS_ALLOC_FAIL == (1ull << 0) as a magic sentinel
instead of (1ull << 2) to free up bit 2.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Patch series "introduce kernel file mapped folios", v4.
Btrfs currently tracks its metadata pages in the page cache, using a fake
inode (fs_info->btree_inode) with offsets corresponding to where the
metadata is stored in the filesystem's full logical address space.
A consequence of this is that when btrfs uses filemap_add_folio(), this
usage is charged to the cgroup of whichever task happens to be running at
the time. These folios don't belong to any particular user cgroup, so I
don't think it makes much sense for them to be charged in that way. Some
negative consequences as a result:
- A task can be holding some important btrfs locks, then need to lookup
some metadata and go into reclaim, extending the duration it holds
that lock for, and unfairly pushing its own reclaim pain onto other
cgroups.
- If that cgroup goes into reclaim, it might reclaim these folios a
different non-reclaiming cgroup might need soon. This is naturally
offset by LRU reclaim, but still.
We have two options for how to manage such file pages:
1. charge them to the root cgroup.
2. don't charge them to any cgroup at all.
2. breaks the invariant that every mapped page has a cgroup. This is
workable, but unnecessarily risky. Therefore, go with 1.
A very similar proposal to use the root cgroup was previously made by Qu,
where he eventually proposed the idea of setting it per address_space.
This makes good sense for the btrfs use case, as the behavior should apply
to all use of the address_space, not select allocations. I.e., if someone
adds another filemap_add_folio() call using btrfs's btree_inode, we would
almost certainly want to account that to the root cgroup as well.
This patch (of 3):
Add the flag AS_KERNEL_FILE to the address_space to indicate that this
mapping's memory is exempt from the usual memcg accounting.
[boris@bur.io: fix CONFIG_MEMCG build for AS_KERNEL_FILE]
Link: https://lkml.kernel.org/r/6de59ddeec81b5c294d337c001ba0061631d4ec6.1755816635.git.boris@bur.io
Link: https://lore.kernel.org/linux-mm/b5fef5372ae454a7b6da4f2f75c427aeab6a07d6.1727498749.git.wqu@suse.com/
Link: https://lkml.kernel.org/r/f09c4e2c90351d4cb30a1969f7a863b9238bd291.1755812945.git.boris@bur.io
Signed-off-by: Boris Burkov <boris@bur.io>
Suggested-by: Qu Wenruo <wqu@suse.com>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
memcg uses TIF_NOTIFY_RESUME to handle reclaiming on exit to user space.
TIF_NOTIFY_RESUME is a multiplexing TIF bit, which is utilized by other
entities as well.
This results in a unconditional mem_cgroup_handle_over_high() call for
every invocation of resume_user_mode_work(), which is a pointless exercise
as most of the time there is no reclaim work to do.
Especially since RSEQ is used by glibc, TIF_NOTIFY_RESUME is raised quite
frequently and the empty calls show up in exit path profiling.
Optimize this by doing a quick check of the reclaim condition before
invoking it.
[akpm@linux-foundation.org: remove now-unneeded test of memcg_nr_pages_over_high==0, per Shakeel]
Link: https://lkml.kernel.org/r/87tt2b6zgs.ffs@tglx
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We will store a flag in the lowest bit of sk->sk_memcg.
Then, we cannot pass the raw pointer to mem_cgroup_under_socket_pressure().
Let's pass struct sock to it and rename the function to match other
functions starting with mem_cgroup_sk_.
Note that the helper is moved to sock.h to use mem_cgroup_from_sk().
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://patch.msgid.link/20250815201712.1745332-10-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We will store a flag in the lowest bit of sk->sk_memcg.
Then, we cannot pass the raw pointer to mem_cgroup_charge_skmem()
and mem_cgroup_uncharge_skmem().
Let's pass struct sock to the functions.
While at it, they are renamed to match other functions starting
with mem_cgroup_sk_.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://patch.msgid.link/20250815201712.1745332-9-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When sk_alloc() allocates a socket, mem_cgroup_sk_alloc() sets
sk->sk_memcg based on the current task.
MPTCP subflow socket creation is triggered from userspace or
an in-kernel worker.
In the latter case, sk->sk_memcg is not what we want. So, we fix
it up from the parent socket's sk->sk_memcg in mptcp_attach_cgroup().
Although the code is placed under #ifdef CONFIG_MEMCG, it is buried
under #ifdef CONFIG_SOCK_CGROUP_DATA.
The two configs are orthogonal. If CONFIG_MEMCG is enabled without
CONFIG_SOCK_CGROUP_DATA, the subflow's memory usage is not charged
correctly.
Let's move the code out of the wrong ifdef guard.
Note that sk->sk_memcg is freed in sk_prot_free() and the parent
sk holds the refcnt of memcg->css here, so we don't need to use
css_tryget().
Fixes: 3764b0c565 ("mptcp: attach subflow socket to parent cgroup")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Link: https://patch.msgid.link/20250815201712.1745332-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
memcg->socket_pressure is initialised with jiffies when the memcg is
created.
Once vmpressure detects that the cgroup is under memory pressure, the
field is updated with jiffies + HZ to signal the fact to the socket layer
and suppress memory allocation for one second.
Otherwise, the field is not updated.
mem_cgroup_under_socket_pressure() uses time_before() to check if jiffies
is less than memcg->socket_pressure, and this has a bug on 32-bit kernel.
if (time_before(jiffies, memcg->socket_pressure))
return true;
As time_before() casts the final result to long, the acceptable delta
between two timestamps is 2 ^ (BITS_PER_LONG - 1).
On 32-bit kernel with CONFIG_HZ=1000, this is about 24 days.
>>> (2 ** 31) / 1000 / 60 / 60 / 24
24.855134814814818
Once 24 days have passed since the last update of socket_pressure,
mem_cgroup_under_socket_pressure() starts to lie until the next 24 days
pass.
We don't need to worry about this on 64-bit machines unless they serve for
300 million years.
>>> (2 ** 63) / 1000 / 60 / 60 / 24 / 365
292471208.6775361
Let's convert memcg->socket_pressure to u64.
Performance teting:
I don't have a real 32-bit machine so this is a result on QEMU, but
with/without the u64 jiffie patch, the time spent in
mem_cgroup_under_socket_pressure() was 1~5us and I didn't see any
measurable delta.
no patch applied:
iperf3 273 [000] 137.296248:
probe:mem_cgroup_under_socket_pressure: (c13660d0)
c13660d1 mem_cgroup_under_socket_pressure+0x1
([kernel.kallsyms])
iperf3 273 [000] 137.296249:
probe:mem_cgroup_under_socket_pressure__return: (c13660d0 <- c1d8fd7f)
iperf3 273 [000] 137.296251:
probe:mem_cgroup_under_socket_pressure: (c13660d0)
c13660d1 mem_cgroup_under_socket_pressure+0x1
([kernel.kallsyms])
iperf3 273 [000] 137.296253:
probe:mem_cgroup_under_socket_pressure__return: (c13660d0 <- c1d8fd7f)
u64 jiffies patch applied:
iperf3 308 [001] 330.669370:
probe:mem_cgroup_under_socket_pressure: (c12ddba0)
c12ddba1 mem_cgroup_under_socket_pressure+0x1
([kernel.kallsyms])
iperf3 308 [001] 330.669371:
probe:mem_cgroup_under_socket_pressure__return: (c12ddba0 <- c1ce98bf)
iperf3 308 [001] 330.669382:
probe:mem_cgroup_under_socket_pressure: (c12ddba0)
c12ddba1 mem_cgroup_under_socket_pressure+0x1
([kernel.kallsyms])
iperf3 308 [001] 330.669384:
probe:mem_cgroup_under_socket_pressure__return: (c12ddba0 <- c1ce98bf)
So the u64 approach is good enough.
Link: https://lkml.kernel.org/r/20250717194645.1096500-1-kuniyu@google.com
Fixes: 8e8ae64524 ("mm: memcontrol: hook up vmpressure to socket pressure")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reported-by: Neal Cardwell <ncardwell@google.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Eric Dumazet <ncardwell@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There are archs which have NMI but does not support this_cpu_* ops safely
in the nmi context but they support safe atomic ops in nmi context. For
such archs, let's add infra to use atomic ops for the memcg stats which
can be updated in nmi.
At the moment, the memcg stats which get updated in the objcg charging
path are MEMCG_KMEM, NR_SLAB_RECLAIMABLE_B & NR_SLAB_UNRECLAIMABLE_B.
Rather than adding support for all memcg stats to be nmi safe, let's just
add infra to make these three stats nmi safe which this patch is doing.
Link: https://lkml.kernel.org/r/20250519063142.111219-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Let's make count_memcg_events re-entrant safe against irqs. The only
thing needed is to convert the usage of __this_cpu_add() to
this_cpu_add(). In addition, with re-entrant safety, there is no need to
disable irqs. Also add warnings for in_nmi() as it is not safe against
nmi context.
Link: https://lkml.kernel.org/r/20250514184158.3471331-5-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Let's make mod_memcg_state re-entrant safe against irqs. The only thing
needed is to convert the usage of __this_cpu_add() to this_cpu_add(). In
addition, with re-entrant safety, there is no need to disable irqs.
mod_memcg_state() is not safe against nmi, so let's add warning if someone
tries to call it in nmi context.
Link: https://lkml.kernel.org/r/20250514184158.3471331-4-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Use kmem_cache for memcg alloc", v3.
(willy tldr: "you've gone from allocating 8 objects per 32KiB to
allocating 13 objects per 32KiB, a 62% improvement in memory consumption"
[1])
The mem_cgroup_alloc function creates mem_cgroup struct and it's
associated structures including mem_cgroup_per_node. Through detailed
analysis on our test machine (Arm64, 16GB RAM, 6.6 kernel, 1 NUMA node,
memcgv2 with nokmem,nosocket,cgroup_disable=pressure), we can observe the
memory allocation for these structures using the following shell commands:
# Enable tracing
echo 1 > /sys/kernel/tracing/events/kmem/kmalloc/enable
echo 1 > /sys/kernel/tracing/tracing_on
cat /sys/kernel/tracing/trace_pipe | grep kmalloc | grep mem_cgroup
# Trigger allocation if cgroup subtree do not enable memcg
echo +memory > /sys/fs/cgroup/cgroup.subtree_control
Ftrace Output:
# mem_cgroup struct allocation
sh-6312 [000] ..... 58015.698365: kmalloc:
call_site=mem_cgroup_css_alloc+0xd8/0x5b4
ptr=000000003e4c3799 bytes_req=2312 bytes_alloc=4096
gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1 accounted=false
# mem_cgroup_per_node allocation
sh-6312 [000] ..... 58015.698389: kmalloc:
call_site=mem_cgroup_css_alloc+0x1d8/0x5b4
ptr=00000000d798700c bytes_req=2896 bytes_alloc=4096
gfp_flags=GFP_KERNEL|__GFP_ZERO node=0 accounted=false
Key Observations:
1. Both structures use kmalloc with requested sizes between 2KB-4KB
2. Allocation alignment forces 4KB slab usage due to pre-defined sizes
(64B, 128B,..., 2KB, 4KB, 8KB)
3. Memory waste per memcg instance:
Base struct: 4096 - 2312 = 1784 bytes
Per-node struct: 4096 - 2896 = 1200 bytes
Total waste: 2984 bytes (1-node system)
NUMA scaling: (1200 + 8) * nr_node_ids bytes
So, it's a little waste.
This patchset introduces dedicated kmem_cache:
Patch2 - mem_cgroup kmem_cache - memcg_cachep
Patch3 - mem_cgroup_per_node kmem_cache - memcg_pn_cachep
The benefits of this change can be observed with the following tracing
commands:
# Enable tracing
echo 1 > /sys/kernel/tracing/events/kmem/kmem_cache_alloc/enable
echo 1 > /sys/kernel/tracing/tracing_on
cat /sys/kernel/tracing/trace_pipe | grep kmem_cache_alloc | grep mem_cgroup
# In another terminal:
echo +memory > /sys/fs/cgroup/cgroup.subtree_control
The output might now look like this:
# mem_cgroup struct allocation
sh-9827 [000] ..... 289.513598: kmem_cache_alloc:
call_site=mem_cgroup_css_alloc+0xbc/0x5d4 ptr=00000000695c1806
bytes_req=2312 bytes_alloc=2368 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1
accounted=false
# mem_cgroup_per_node allocation
sh-9827 [000] ..... 289.513602: kmem_cache_alloc:
call_site=mem_cgroup_css_alloc+0x1b8/0x5d4 ptr=000000002989e63a
bytes_req=2896 bytes_alloc=2944 gfp_flags=GFP_KERNEL|__GFP_ZERO node=0
accounted=false
This indicates that the `mem_cgroup` struct now requests 2312 bytes and is
allocated 2368 bytes, while `mem_cgroup_per_node` requests 2896 bytes and
is allocated 2944 bytes. The slight increase in allocated size is due to
`SLAB_HWCACHE_ALIGN` in the `kmem_cache`.
Without `SLAB_HWCACHE_ALIGN`, the allocation might appear as:
# mem_cgroup struct allocation
sh-9269 [003] ..... 80.396366: kmem_cache_alloc:
call_site=mem_cgroup_css_alloc+0xbc/0x5d4 ptr=000000005b12b475
bytes_req=2312 bytes_alloc=2312 gfp_flags=GFP_KERNEL|__GFP_ZERO node=-1
accounted=false
# mem_cgroup_per_node allocation
sh-9269 [003] ..... 80.396411: kmem_cache_alloc:
call_site=mem_cgroup_css_alloc+0x1b8/0x5d4 ptr=00000000f347adc6
bytes_req=2896 bytes_alloc=2896 gfp_flags=GFP_KERNEL|__GFP_ZERO node=0
accounted=false
While the `bytes_alloc` now matches the `bytes_req`, this patchset
defaults to using `SLAB_HWCACHE_ALIGN` as it is generally considered more
beneficial for performance. Please let me know if there are any issues or
if I've misunderstood anything.
This patchset also move mem_cgroup_init ahead of cgroup_init() due to
cgroup_init() will allocate root_mem_cgroup, but each initcall invoke
after cgroup_init, so if each kmem_cache do not prepare, we need testing
NULL before use it.
This patch (of 3):
When cgroup_init() creates root_mem_cgroup through css_alloc callback,
some critical resources might not be fully initialized, forcing later
operations to perform conditional checks for resource availability.
This patch move mem_cgroup_init() to address the init order, it invoke
before cgroup_init, so, compare to subsys_initcall, it can use to prepare
some key resources before root_mem_cgroup alloc.
Link: https://lkml.kernel.org/r/aAsRCj-niMMTtmK8@casper.infradead.org [1]
Link: https://lkml.kernel.org/r/20250425031935.76411-1-link@vivo.com
Link: https://lkml.kernel.org/r/20250425031935.76411-2-link@vivo.com
Signed-off-by: Huan Yang <link@vivo.com>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Francesco Valla <francesco@valla.it>
Cc: guoweikang <guoweikang.kernel@gmail.com>
Cc: Huang Shijie <shijie@os.amperecomputing.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Raul E Rangel <rrangel@chromium.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
It is possible for a reclaimer to cause demotions of an lruvec belonging
to a cgroup with cpuset.mems set to exclude some nodes. Attempt to apply
this limitation based on the lruvec's memcg and prevent demotion.
Notably, this may still allow demotion of shared libraries or any memory
first instantiated in another cgroup. This means cpusets still cannot
cannot guarantee complete isolation when demotion is enabled, and the docs
have been updated to reflect this.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently - with the noted exceptions.
Note on locking:
The cgroup_get_e_css reference protects the css->effective_mems, and calls
of this interface would be subject to the same race conditions associated
with a non-atomic access to cs->effective_mems.
So while this interface cannot make strong guarantees of correctness, it
can therefore avoid taking a global or rcu_read_lock for performance.
Link: https://lkml.kernel.org/r/20250424202806.52632-3-gourry@gourry.net
Signed-off-by: Gregory Price <gourry@gourry.net>
Suggested-by: Shakeel Butt <shakeel.butt@linux.dev>
Suggested-by: Waiman Long <longman@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kpageflags_read() and kpagecgroup_read() are quite similar to
kpagecount_read(). Refactor common code into a helper function to reduce
code duplication.
Link: https://lkml.kernel.org/r/20250318063226.223284-1-liuyerd@163.com
Signed-off-by: Liu Ye <liuye@kylinos.cn>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Svetly Todorov <svetly.todorov@memverge.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There's no need to check which kind of pointer is in the memcg_data field,
all we actually care about is whether it's zero or not. Saves 70 bytes in
workingset_activation() with the Debian config.
Link: https://lkml.kernel.org/r/20250314133617.138071-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The last argument to split_page_memcg() is now always 0, so remove it,
effectively reverting commit b8791381d7.
Link: https://lkml.kernel.org/r/20250314133617.138071-3-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Minor memcg cleanups & prep for memdescs", v2.
Separate the handling of accounted folios and GFP_ACCOUNT pages for easier
to understand code. For more detail, see
https://lore.kernel.org/linux-mm/Z9LwTOudOlCGny3f@casper.infradead.org/
This patch (of 5):
Folios always use memcg_data to refer to the mem_cgroup while pages
allocated with GFP_ACCOUNT have a pointer to the obj_cgroup. Since the
caller already knows what it has, split the function into two and then we
don't need to check.
Move the assignment of split folio memcg_data to the point where we set up
the other parts of the new folio. That leaves folio_split_memcg_refs()
just handling the memcg accounting.
Link: https://lkml.kernel.org/r/20250314133617.138071-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20250314133617.138071-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The interweaving of two entirely different swap accounting strategies has
been one of the more confusing parts of the memcg code. Split out the v1
code to clarify the implementation and a handful of callsites, and to
avoid building the v1 bits when !CONFIG_MEMCG_V1.
text data bss dec hex filename
39253 6446 4160 49859 c2c3 mm/memcontrol.o.old
38877 6382 4160 49419 c10b mm/memcontrol.o
Link: https://lkml.kernel.org/r/20250124054132.45643-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch fully removes the mem_cgroup_{try, commit, cancel}_charge
functions, as well as their hugetlb variants.
Link: https://lkml.kernel.org/r/20241211203951.764733-4-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This patch introduces mem_cgroup_charge_hugetlb which combines the logic
of mem_cgroup_hugetlb_try_charge / mem_cgroup_hugetlb_commit_charge and
removes the need for mem_cgroup_hugetlb_cancel_charge. It also reduces
the footprint of memcg in hugetlb code and consolidates all memcg related
error paths into one.
Link: https://lkml.kernel.org/r/20241211203951.764733-3-joshua.hahnjy@gmail.com
Signed-off-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Linus Torvalds