linux/mm
Roman Gushchin fb2f2b0adb mm: memcg/slab: reparent memcg kmem_caches on cgroup removal
Let's reparent non-root kmem_caches on memcg offlining.  This allows us to
release the memory cgroup without waiting for the last outstanding kernel
object (e.g.  dentry used by another application).

Since the parent cgroup is already charged, everything we need to do is to
splice the list of kmem_caches to the parent's kmem_caches list, swap the
memcg pointer, drop the css refcounter for each kmem_cache and adjust the
parent's css refcounter.

Please, note that kmem_cache->memcg_params.memcg isn't a stable pointer
anymore.  It's safe to read it under rcu_read_lock(), cgroup_mutex held,
or any other way that protects the memory cgroup from being released.

We can race with the slab allocation and deallocation paths.  It's not a
big problem: parent's charge and slab global stats are always correct, and
we don't care anymore about the child usage and global stats.  The child
cgroup is already offline, so we don't use or show it anywhere.

Local slab stats (NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE) aren't
used anywhere except count_shadow_nodes().  But even there it won't break
anything: after reparenting "nodes" will be 0 on child level (because
we're already reparenting shrinker lists), and on parent level page stats
always were 0, and this patch won't change anything.

[guro@fb.com: properly handle kmem_caches reparented to root_mem_cgroup]
  Link: http://lkml.kernel.org/r/20190620213427.1691847-1-guro@fb.com
Link: http://lkml.kernel.org/r/20190611231813.3148843-11-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-12 11:05:44 -07:00
..
kasan mm/kasan: change kasan_check_{read,write} to return boolean 2019-07-12 11:05:42 -07:00
backing-dev.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
balloon_compaction.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
cleancache.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
cma_debug.c mm/cma_debug.c: fix the break condition in cma_maxchunk_get() 2019-05-14 09:47:45 -07:00
cma.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 98 2019-05-24 17:37:54 +02:00
cma.h
compaction.c mm, compaction: make sure we isolate a valid PFN 2019-06-01 15:51:32 -07:00
debug_page_ref.c
debug.c mm: update references to page _refcount 2019-05-14 19:52:47 -07:00
dmapool.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 403 2019-06-05 17:37:13 +02:00
early_ioremap.c
fadvise.c
failslab.c mm/failslab.c: by default, do not fail allocations with direct reclaim only 2019-07-12 11:05:43 -07:00
filemap.c mm/filemap.c: correct the comment about VM_FAULT_RETRY 2019-07-12 11:05:43 -07:00
frame_vector.c
frontswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
gup_benchmark.c mm/gup: replace get_user_pages_longterm() with FOLL_LONGTERM 2019-05-14 09:47:45 -07:00
gup.c mm/gup.c: make follow_page_mask() static 2019-07-12 11:05:42 -07:00
highmem.c mm: convert totalram_pages and totalhigh_pages variables to atomic 2018-12-28 12:11:47 -08:00
hmm.c mm/devm_memremap_pages: fix final page put race 2019-06-13 17:34:56 -10:00
huge_memory.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
hugetlb_cgroup.c
hugetlb.c mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge 2019-06-29 16:43:45 +08:00
hwpoison-inject.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
init-mm.c
internal.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
interval_tree.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 248 2019-06-19 17:09:08 +02:00
Kconfig Linux 5.2-rc4 2019-06-14 14:18:53 -06:00
Kconfig.debug mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
khugepaged.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
kmemleak-test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
kmemleak.c mm/kmemleak.c: change error at _write when kmemleak is disabled 2019-07-12 11:05:42 -07:00
ksm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 482 2019-06-19 17:09:52 +02:00
list_lru.c mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages 2019-07-12 11:05:44 -07:00
maccess.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
madvise.c mm/mmu_notifier: use correct mmu_notifier events for each invalidation 2019-05-14 09:47:49 -07:00
Makefile mm: shuffle initial free memory to improve memory-side-cache utilization 2019-05-14 19:52:48 -07:00
memblock.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
memcontrol.c mm: memcg/slab: reparent memcg kmem_caches on cgroup removal 2019-07-12 11:05:44 -07:00
memfd.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
memory_hotplug.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
memory-failure.c Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2019-07-08 21:48:15 -07:00
memory.c mm, swap: fix race between swapoff and some swap operations 2019-07-12 11:05:43 -07:00
mempolicy.c mm/mempolicy.c: fix an incorrect rebind node in mpol_rebind_nodemask 2019-06-29 16:43:44 +08:00
mempool.c docs/core-api/mm: fix return value descriptions in mm/ 2019-03-05 21:07:20 -08:00
memtest.c
migrate.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
mincore.c mm/mincore.c: fix race between swapoff and mincore 2019-07-12 11:05:43 -07:00
mlock.c mm/mlock.c: change count_mm_mlocked_page_nr return type 2019-06-13 17:34:56 -10:00
mm_init.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
mmu_context.c
mmu_gather.c mm: mmu_gather: remove __tlb_reset_range() for force flush 2019-06-13 17:34:56 -10:00
mmu_notifier.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
mmzone.c
mprotect.c mm/mprotect.c: fix compilation warning because of unused 'mm' variable 2019-05-14 09:47:51 -07:00
mremap.c mm/mmu_notifier: contextual information for event triggering invalidation 2019-05-14 09:47:49 -07:00
msync.c
nommu.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
oom_kill.c mm/oom_kill.c: fix uninitialized oc->constraint 2019-06-29 16:43:45 +08:00
page_alloc.c mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
page_counter.c
page_ext.c mm, debug_pagealloc: use a page type instead of page_ext flag 2019-07-12 11:05:43 -07:00
page_idle.c mm/page_idle.c: fix oops because end_pfn is larger than max_pfn 2019-06-29 16:43:45 +08:00
page_io.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
page_isolation.c mm/page_isolation.c: change the prototype of undo_isolate_page_range() 2019-07-12 11:05:43 -07:00
page_owner.c mm/page_owner: Simplify stack trace handling 2019-04-29 12:37:50 +02:00
page_poison.c page_poison: play nicely with KASAN 2019-03-05 21:07:13 -08:00
page_vma_mapped.c
page-writeback.c mm: remove the account_page_dirtied export 2019-07-12 11:05:42 -07:00
pagewalk.c
percpu-internal.h percpu: convert chunk hints to be based on pcpu_block_md 2019-03-13 12:25:31 -07:00
percpu-km.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-stats.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu-vm.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
percpu.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
pgtable-generic.c
process_vm_access.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
quicklist.c
readahead.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
rmap.c mm/rmap.c: use the pra.mapcount to do the check 2019-05-14 09:47:49 -07:00
rodata_test.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
shmem.c Revert "mm: page cache: store only head pages in i_pages" 2019-07-05 19:55:18 -07:00
shuffle.c mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
shuffle.h mm: maintain randomization of page free lists 2019-05-14 19:52:48 -07:00
slab_common.c mm: memcg/slab: reparent memcg kmem_caches on cgroup removal 2019-07-12 11:05:44 -07:00
slab.c mm: memcg/slab: unify SLAB and SLUB page accounting 2019-07-12 11:05:44 -07:00
slab.h mm: memcg/slab: reparent memcg kmem_caches on cgroup removal 2019-07-12 11:05:44 -07:00
slob.c mm/slab: refactor common ksize KASAN logic into slab_common.c 2019-07-12 11:05:42 -07:00
slub.c mm: memcg/slab: unify SLAB and SLUB page accounting 2019-07-12 11:05:44 -07:00
sparse-vmemmap.c
sparse.c mm/sparse.c: clean up obsolete code comment 2019-05-14 09:47:48 -07:00
swap_cgroup.c
swap_slots.c
swap_state.c mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device() 2019-07-12 11:05:43 -07:00
swap.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
swapfile.c mm, swap: use rbtree for swap_extent 2019-07-12 11:05:43 -07:00
truncate.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
usercopy.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
userfaultfd.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 2019-06-19 17:09:53 +02:00
util.c prctl_set_mm: downgrade mmap_sem to read lock 2019-06-01 15:51:31 -07:00
vmacache.c
vmalloc.c arm64 updates for 5.3: 2019-07-08 09:54:55 -07:00
vmpressure.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
vmscan.c mm: vmscan: scan anonymous pages on file refaults 2019-07-12 11:05:39 -07:00
vmstat.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
workingset.c mm: memcontrol: make cgroup stats and events query API explicitly local 2019-05-14 19:52:53 -07:00
z3fold.c mm/z3fold.c: lock z3fold page before __SetPageMovable() 2019-07-12 11:05:40 -07:00
zbud.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zpool.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
zsmalloc.c
zswap.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157 2019-05-30 11:26:37 -07:00