Commit Graph

37 Commits

Author SHA1 Message Date
Breno Leitao
1833ce36b3 mm: memcg: initialize *locked in memcg1_oom_prepare() stub
mem_cgroup_oom() passes an uninitialized "locked" to memcg1_oom_prepare()
and reads it back in memcg1_oom_finish():

	bool locked, ret;
	...
	if (!memcg1_oom_prepare(memcg, &locked))
		return false;
	ret = mem_cgroup_out_of_memory(memcg, mask, order);
	memcg1_oom_finish(memcg, locked);

This relies on memcg1_oom_prepare() setting *locked whenever it returns
true.  The CONFIG_MEMCG_V1=y version does, but the stub used when
CONFIG_MEMCG_V1=n returns true without touching *locked, so
memcg1_oom_finish() consumes an uninitialized value.  On a memcg OOM this
is reported by UBSAN:

  UBSAN: invalid-load in mm/memcontrol.c:1932:27
  load of value 0 is not a valid value for type 'bool' (aka '_Bool')

Initialize *locked to false in the stub; with cgroup v1 compiled out there
is no OOM lock to take.

Link: https://lore.kernel.org/20260716-memcg-oom-uninit-locked-v2-1-63631d878eb4@debian.org
Fixes: e93d4166b4 ("mm: memcg: put cgroup v1-specific code under a config option")
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28 17:37:31 -07:00
Qi Zheng
8285917d6f mm: memcontrol: prepare for reparenting non-hierarchical stats
To resolve the dying memcg issue, we need to reparent LRU folios of child
memcg to its parent memcg.  This could cause problems for non-hierarchical
stats.

As Yosry Ahmed pointed out:

In short, if memory is charged to a dying cgroup at the time of
reparenting, when the memory gets uncharged the stats updates will occur
at the parent. This will update both hierarchical and non-hierarchical
stats of the parent, which would corrupt the parent's non-hierarchical
stats (because those counters were never incremented when the memory was
charged).

Now we have the following two types of non-hierarchical stats, and they
are only used in CONFIG_MEMCG_V1:

a. memcg->vmstats->state_local[i]
b. pn->lruvec_stats->state_local[i]

To ensure that these non-hierarchical stats work properly, we need to
reparent these non-hierarchical stats after reparenting LRU folios. To
this end, this commit makes the following preparations:

1. implement reparent_state_local() to reparent non-hierarchical stats
2. make css_killed_work_fn() to be called in rcu work, and implement
   get_non_dying_memcg_start() and get_non_dying_memcg_end() to avoid race
   between mod_memcg_state()/mod_memcg_lruvec_state()
   and reparent_state_local()

Link: https://lore.kernel.org/e862995c45a7101a541284b6ebee5e5c32c89066.1772711148.git.zhengqi.arch@bytedance.com
Co-developed-by: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chen Ridong <chenridong@huawei.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Imran Khan <imran.f.khan@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-18 00:10:47 -07:00
Kairui Song
37cb8cd043 memcg: consolidate private id refcount get/put helpers
We currently have two different sets of helpers for getting or putting the
private IDs' refcount for order 0 and large folios.  This is redundant. 
Just use one and always acquire the refcount of the swapout folio size
unless it's zero, and put the refcount using the folio size if the charge
failed, since the folio size can't change.  Then there is no need to
update the refcount for tail pages.

Same for freeing, then only one pair of get/put helper is needed now.

The performance might be slightly better, too: both "inc unless zero" and
"add unless zero" use the same cmpxchg implementation.  For large folios,
we saved an atomic operation.  And for both order 0 and large folios, we
saved a branch.

Link: https://lkml.kernel.org/r/20260213-memcg-privid-v1-1-d8cb7afcf831@tencent.com
Signed-off-by: Kairui Song <kasong@tencent.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Chen Ridong <chenridong@huaweicloud.com>
Acked-by: Shakeel Butt <shakeel.butt@gmail.com>
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>
2026-04-05 13:53:00 -07:00
Linus Torvalds
4cff5c05e0 mm.git review status for linus..mm-stable
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
  ...
2026-02-12 11:32:37 -08:00
Shakeel Butt
e77786b468 memcg: introduce private id API for in-kernel users
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>
2026-01-26 20:02:23 -08:00
Chen Ridong
558605a530 memcg: move mem_cgroup_usage memcontrol-v1.c
Patch series "memcg cleanups", v3.

Two code moves/removals with no behavior change.


This patch (of 2):

Currently, mem_cgroup_usage is only used for v1, just move it to
memcontrol-v1.c

Link: https://lkml.kernel.org/r/20251211013019.2080004-1-chenridong@huaweicloud.com
Link: https://lkml.kernel.org/r/20251211013019.2080004-2-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: 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>
2026-01-20 19:24:41 -08:00
Roman Gushchin
4221de8c41 mm: declare memcg_page_state_output() in memcontrol.h
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>
2025-12-22 22:20:21 -08:00
Shakeel Butt
cb44821e1f memcg: move do_memsw_account() to CONFIG_MEMCG_V1
The do_memsw_account() is used to enable or disable legacy memory+swap
accounting in memory cgroup.  However with disabled CONFIG_MEMCG_V1, we
don't need to keep checking it.  So, let's always return false for
!CONFIG_MEMCG_V1 configs.

Before the patch:

$ size mm/memcontrol.o
   text    data     bss     dec     hex filename
  49928   10736    4172   64836    fd44 mm/memcontrol.o

After the patch:

$ size mm/memcontrol.o
   text    data     bss     dec     hex filename
  49430   10480    4172   64082    fa52 mm/memcontrol.o

Link: https://lkml.kernel.org/r/20250312222552.3284173-1-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@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>
2025-03-21 22:03:11 -07:00
Johannes Weiner
89ce924f0b mm: memcontrol: move memsw charge callbacks to v1
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>
2025-03-16 22:05:55 -07:00
Johannes Weiner
0d892bbbfa mm: memcontrol: move stray ratelimit bits to v1
41213dd0f8 ("memcg: move mem_cgroup_event_ratelimit to v1 code") left
this one behind.  There are no v2 references.

Link: https://lkml.kernel.org/r/20250124043859.18808-2-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:05:55 -07:00
Johannes Weiner
75fe8ec238 mm: memcontrol: unshare v2-only charge API bits again
6b611388b6 ("memcg-v1: remove charge move code") removed the remaining
v1 callers.

Link: https://lkml.kernel.org/r/20250124043859.18808-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:05:55 -07:00
Chen Ridong
610dc18c50 memcg: add CONFIG_MEMCG_V1 for 'local' functions
Add CONFIG_MEMCG_V1 for the 'local' functions, which are only used in
memcg v1, so that they won't be built for v2.

Link: https://lkml.kernel.org/r/20250124073514.2375622-5-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
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 Finkel <davidf@vimeo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:05:54 -07:00
John Sperbeck
89dd878282 mm: memcg: declare do_memsw_account inline
In commit 66d60c428b ("mm: memcg: move legacy memcg event code into
memcontrol-v1.c"), the static do_memsw_account() function was moved from a
.c file to a .h file.  Unfortunately, the traditional inline keyword
wasn't added.  If a file (e.g., a unit test) includes the .h file, but
doesn't refer to do_memsw_account(), it will get a warning like:

mm/memcontrol-v1.h:41:13: warning: unused function 'do_memsw_account' [-Wunused-function]
   41 | static bool do_memsw_account(void)
      |             ^~~~~~~~~~~~~~~~

Link: https://lkml.kernel.org/r/20241128203959.726527-1-jsperbeck@google.com
Fixes: 66d60c428b ("mm: memcg: move legacy memcg event code into memcontrol-v1.c")
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Acked-by: 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>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-05 19:54:46 -08:00
Shakeel Butt
6b611388b6 memcg-v1: remove charge move code
The memcg-v1 charge move feature has been deprecated completely and let's
remove the relevant code as well.

Link: https://lkml.kernel.org/r/20241025012304.2473312-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:18 -08:00
Michal Koutný
f2c5101be4 memcg: cleanup with !CONFIG_MEMCG_V1
Extern declarations have no definitions with !CONFIG_MEMCG_V1 and no
users, drop them altogether.

Link: https://lkml.kernel.org/r/20240909163223.3693529-1-mkoutny@suse.com
Link: https://lkml.kernel.org/r/20240909163223.3693529-2-mkoutny@suse.com
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Chen Ridong <chenridong@huawei.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>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 01:07:00 -07:00
Shakeel Butt
0ccaf421d6 memcg: allocate v1 event percpu only on v1 deployment
Currently memcg->events_percpu gets allocated on v2 deployments.  Let's
move the allocation to v1 only codebase.  This is not needed in v2.

Link: https://lkml.kernel.org/r/20240815050453.1298138-7-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
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: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:20 -07:00
Shakeel Butt
a5ebe6bbe5 memcg: make v1 only functions static
The functions memcg1_charge_statistics() and memcg1_check_events() are
never used outside of v1 source file.  So, make them static.

Link: https://lkml.kernel.org/r/20240815050453.1298138-6-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
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: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:19 -07:00
Shakeel Butt
f7d49ba03a memcg: move v1 events and statistics code to v1 file
Currently the common code path for charge commit, swapout and batched
uncharge are executing v1 only code which is completely useless for the v2
deployments where CONFIG_MEMCG_V1 is disabled.  In addition, it is mucking
with IRQs which might be slow on some architectures.  Let's move all of
this code to v1 only code and remove them from v2 only deployments.

Link: https://lkml.kernel.org/r/20240815050453.1298138-5-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
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: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:19 -07:00
Shakeel Butt
7d7602b4be memcg: move mem_cgroup_charge_statistics to v1 code
There are no callers of mem_cgroup_charge_statistics() in the v2 code
base, so move it to the v1 only code and rename it to
memcg1_charge_statistics().

Link: https://lkml.kernel.org/r/20240815050453.1298138-4-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
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: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:19 -07:00
Shakeel Butt
41213dd0f8 memcg: move mem_cgroup_event_ratelimit to v1 code
There are no callers of mem_cgroup_event_ratelimit() in the v2 code.  Move
it to v1 only code and rename it to memcg1_event_ratelimit().

Link: https://lkml.kernel.org/r/20240815050453.1298138-3-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
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: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:19 -07:00
Shakeel Butt
5d383b69a0 memcg: move v1 only percpu stats in separate struct
Patch series "memcg: further decouple v1 code from v2".

Some of the v1 code is still in v2 code base due to v1 fields in the
struct memcg_vmstats_percpu.  This field decouples those fileds from v2
struct and move all the related code into v1 only code base.


This patch (of 7):

At the moment struct memcg_vmstats_percpu contains two v1 only fields
which consumes memory even when CONFIG_MEMCG_V1 is not enabled.  In
addition there are v1 only functions accessing them and are in the main
memcontrol source file and can not be moved to v1 only source file due to
these fields.  Let's move these fields into their own struct.  Later
patches will move the functions accessing them to v1 source file and only
allocate these fields when CONFIG_MEMCG_V1 is enabled.

Link: https://lkml.kernel.org/r/20240815050453.1298138-1-shakeel.butt@linux.dev
Link: https://lkml.kernel.org/r/20240815050453.1298138-2-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: 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>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-01 20:26:18 -07:00
Roman Gushchin
b5855a26de mm: memcg: gather memcg1-specific fields initialization in memcg1_memcg_init()
Gather all memcg1-specific struct mem_cgroup's members initialization in a
new memcg1_memcg_init() function, defined in mm/memcontrol-v1.c. 
Obviously, if CONFIG_MEMCG_V1 is not set, there is no need to initialize
these fields, so the function becomes trivial.

Link: https://lkml.kernel.org/r/20240628210317.272856-5-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@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>
2024-07-04 18:05:56 -07:00
Roman Gushchin
773e9ae77f mm: memcg: factor out legacy socket memory accounting code
Move out the legacy cgroup v1 socket memory accounting code into
mm/memcontrol-v1.c.

This commit introduces three new functions: memcg1_tcpmem_active(),
memcg1_charge_skmem() and memcg1_uncharge_skmem(), which contain all
cgroup v1-specific code and become trivial if CONFIG_MEMCG_V1 isn't set.

Note, that !!memcg->tcpmem_pressure check in
mem_cgroup_under_socket_pressure() can't be easily moved into
memcontrol-v1.h without including memcontrol-v1.h from memcontrol.h which
isn't a good idea, so it's better to just #ifdef it.

Link: https://lkml.kernel.org/r/20240628210317.272856-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@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>
2024-07-04 18:05:55 -07:00
Roman Gushchin
04fbe921d3 mm: memcg: move memcg_account_kmem() to memcontrol-v1.c
Patch series "mm: memcg: put cgroup v1-specific memcg data under
CONFIG_MEMCG_V1".

This patchset puts all cgroup v1's members of struct mem_cgroup, struct
mem_cgroup_per_node and struct task_struct under the CONFIG_MEMCG_V1
config option.  If cgroup v1 support is not required (and it's true for
many cgroup users these days), it allows to save a bit of memory and
compile out some code, some of which is on relatively hot paths.  It also
structures the code a bit better by grouping cgroup v1-specific stuff in
one place.


This patch (of 9):

memcg_account_kmem() consists of a trivial statistics change via
mod_memcg_state() call and a relatively large memcg1-specific part.

Let's factor out the mod_memcg_state() call and move the rest into the
mm/memcontrol-v1.c file.  Also rename memcg_account_kmem() into
memcg1_account_kmem() for consistency.

Link: https://lkml.kernel.org/r/20240628210317.272856-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240628210317.272856-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@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>
2024-07-04 18:05:55 -07:00
Roman Gushchin
e93d4166b4 mm: memcg: put cgroup v1-specific code under a config option
Put legacy cgroup v1 memory controller code under a new CONFIG_MEMCG_V1
config option.  The option is turned off by default.  Nobody except those
who are still using cgroup v1 should turn it on.

If the option is not set, memory controller can still be mounted under
cgroup v1, but none of memcg-specific control files are present.

Please note, that not all cgroup v1's memory controller code is guarded
yet (but most of it), it's a subject for some follow-up work.

Thanks to Michal Hocko for providing a better Kconfig option description.

[roman.gushchin@linux.dev: better config option description provided by Michal]
  Link: https://lkml.kernel.org/r/ZnxXNtvqllc9CDoo@google.com
Link: https://lkml.kernel.org/r/20240625005906.106920-14-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:54 -07:00
Roman Gushchin
6f1173d684 mm: memcg: group cgroup v1 memcg related declarations
Group all cgroup v1-related declarations at the end of memcontrol.h and
mm/memcontrol-v1.h with an intention to put them all together under a
config option later on.  It should make things easier to follow and
maintain too.

Link: https://lkml.kernel.org/r/20240625005906.106920-13-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:54 -07:00
Roman Gushchin
34926e10bb mm: memcg: make memcg1_update_tree() static
memcg1_update_tree() is not used outside of mm/memcontrol-v1.c anymore,
define it as static and remove the declaration from the header file.

Link: https://lkml.kernel.org/r/20240625005906.106920-12-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:54 -07:00
Roman Gushchin
ea1e879631 mm: memcg: move cgroup v1 interface files to memcontrol-v1.c
Move legacy cgroup v1 memory controller interfaces and corresponding code
into memcontrol-v1.c.

[roman.gushchin@linux.dev: move two functions]
  Link: https://lkml.kernel.org/r/20240704002712.2077812-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240625005906.106920-11-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:53 -07:00
Roman Gushchin
8d49b69920 mm: memcg: rename memcg_oom_recover()
Rename memcg_oom_recover() into memcg1_oom_recover() for consistency with
other memory cgroup v1-related functions.

Move the declaration in mm/memcontrol-v1.h to be nearby other memcg v1 oom
handling functions.

Link: https://lkml.kernel.org/r/20240625005906.106920-10-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:53 -07:00
Roman Gushchin
292fc2e020 mm: memcg: move cgroup v1 oom handling code into memcontrol-v1.c
Cgroup v1 supports a complicated OOM handling in userspace mechanism,
which is not supported by cgroup v2.  Let's move the corresponding code
into memcontrol-v1.c.

Aside from mechanical code movement this patch introduces two new
functions: memcg1_oom_prepare() and memcg1_oom_finish().  Those are
implementing cgroup v1-specific parts of the common memcg OOM handling
path.

Link: https://lkml.kernel.org/r/20240625005906.106920-9-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:53 -07:00
Roman Gushchin
cc7b8504f6 mm: memcg: rename memcg_check_events()
Rename memcg_check_events() into memcg1_check_events() for consistency
with other cgroup v1-specific functions.

Link: https://lkml.kernel.org/r/20240625005906.106920-8-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:53 -07:00
Roman Gushchin
66d60c428b mm: memcg: move legacy memcg event code into memcontrol-v1.c
Cgroup v1's memory controller contains a pretty complicated event
notifications mechanism which is not used on cgroup v2.  Let's move the
corresponding code into memcontrol-v1.c.

Please, note, that mem_cgroup_event_ratelimit() remains in memcontrol.c,
otherwise it would require exporting too many details on memcg stats
outside of memcontrol.c.

Link: https://lkml.kernel.org/r/20240625005906.106920-7-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:52 -07:00
Roman Gushchin
b9eaacb1db mm: memcg: rename charge move-related functions
Rename exported function related to the charge move to have the memcg1_
prefix.

Link: https://lkml.kernel.org/r/20240625005906.106920-6-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:52 -07:00
Roman Gushchin
e548ad4a7c mm: memcg: move charge migration code to memcontrol-v1.c
Unlike the legacy cgroup v1 memory controller, cgroup v2 memory controller
doesn't support moving charged pages between cgroups.

It's a fairly large and complicated code which created a number of
problems in the past.  Let's move this code into memcontrol-v1.c.  It
shaves off 1k lines from memcontrol.c.  It's also another step towards
making the legacy memory controller code optionally compiled.

Link: https://lkml.kernel.org/r/20240625005906.106920-5-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:52 -07:00
Roman Gushchin
87024f5837 mm: memcg: rename soft limit reclaim-related functions
Rename exported function related to the softlimit reclaim to have memcg1_
prefix.

Link: https://lkml.kernel.org/r/20240625005906.106920-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:52 -07:00
Roman Gushchin
d12f6d2241 mm: memcg: move soft limit reclaim code to memcontrol-v1.c
Soft limits are cgroup v1-specific and are not supported by cgroup v2, so
let's move the corresponding code into memcontrol-v1.c.

Aside from simple moving the code, this commits introduces a trivial
memcg1_soft_limit_reset() function to reset soft limits and also moves the
global soft limit tree initialization code into a new memcg1_init()
function.

It also moves corresponding declarations shared between memcontrol.c and
memcontrol-v1.c into mm/memcontrol-v1.h.

Link: https://lkml.kernel.org/r/20240625005906.106920-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:51 -07:00
Roman Gushchin
1b1e13440c mm: memcg: introduce memcontrol-v1.c
Patch series "mm: memcg: separate legacy cgroup v1 code and put under
config option", v2.

Cgroups v2 have been around for a while and many users have fully adopted
them, so they never use cgroups v1 features and functionality.  Yet they
have to "pay" for the cgroup v1 support anyway:
1) the kernel binary contains an unused cgroup v1 code,
2) some code paths have additional checks which are not needed,
3) some common structures like task_struct and mem_cgroup contain unused
   cgroup v1-specific members.

Cgroup v1's memory controller has a number of features that are not
supported by cgroup v2 and their implementation is pretty much self
contained.  Most notably, these features are: soft limit reclaim, oom
handling in userspace, complicated event notification system, charge
migration.  Cgroup v1-specific code in memcontrol.c is close to 4k lines
in size and it's intervened with generic and cgroup v2-specific code. 
It's a burden on developers and maintainers.

This patchset aims to solve these problems by:
1) moving cgroup v1-specific memcg code to the new mm/memcontrol-v1.c file,
2) putting definitions shared by memcontrol.c and memcontrol-v1.c into the
   mm/memcontrol-v1.h header,
3) introducing the CONFIG_MEMCG_V1 config option, turned off by default,
4) making memcontrol-v1.c to compile only if CONFIG_MEMCG_V1 is set.

If CONFIG_MEMCG_V1 is not set, cgroup v1 memory controller is still available
for mounting, however no memory-specific control knobs are present.

This patch (of 14):


This patch introduces the mm/memcontrol-v1.c source file which will be
used for all legacy (cgroup v1) memory cgroup code.  It also introduces
mm/memcontrol-v1.h to keep declarations shared between mm/memcontrol.c and
mm/memcontrol-v1.c.

As of now, let's compile it if CONFIG_MEMCG is set, similar to
mm/memcontrol.c.  Later on it can be switched to use a separate config
option, so that the legacy code won't be compiled if not required.

Link: https://lkml.kernel.org/r/20240625005906.106920-1-roman.gushchin@linux.dev
Link: https://lkml.kernel.org/r/20240625005906.106920-2-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-04 18:05:51 -07:00