linux/mm
Johannes Weiner 73f576c04b mm: memcontrol: fix cgroup creation failure after many small jobs
The memory controller has quite a bit of state that usually outlives the
cgroup and pins its CSS until said state disappears.  At the same time
it imposes a 16-bit limit on the CSS ID space to economically store IDs
in the wild.  Consequently, when we use cgroups to contain frequent but
small and short-lived jobs that leave behind some page cache, we quickly
run into the 64k limitations of outstanding CSSs.  Creating a new cgroup
fails with -ENOSPC while there are only a few, or even no user-visible
cgroups in existence.

Although pinning CSSs past cgroup removal is common, there are only two
instances that actually need an ID after a cgroup is deleted: cache
shadow entries and swapout records.

Cache shadow entries reference the ID weakly and can deal with the CSS
having disappeared when it's looked up later.  They pose no hurdle.

Swap-out records do need to pin the css to hierarchically attribute
swapins after the cgroup has been deleted; though the only pages that
remain swapped out after offlining are tmpfs/shmem pages.  And those
references are under the user's control, so they are manageable.

This patch introduces a private 16-bit memcg ID and switches swap and
cache shadow entries over to using that.  This ID can then be recycled
after offlining when the CSS remains pinned only by objects that don't
specifically need it.

This script demonstrates the problem by faulting one cache page in a new
cgroup and deleting it again:

  set -e
  mkdir -p pages
  for x in `seq 128000`; do
    [ $((x % 1000)) -eq 0 ] && echo $x
    mkdir /cgroup/foo
    echo $$ >/cgroup/foo/cgroup.procs
    echo trex >pages/$x
    echo $$ >/cgroup/cgroup.procs
    rmdir /cgroup/foo
  done

When run on an unpatched kernel, we eventually run out of possible IDs
even though there are no visible cgroups:

  [root@ham ~]# ./cssidstress.sh
  [...]
  65000
  mkdir: cannot create directory '/cgroup/foo': No space left on device

After this patch, the IDs get released upon cgroup destruction and the
cache and css objects get released once memory reclaim kicks in.

[hannes@cmpxchg.org: init the IDR]
  Link: http://lkml.kernel.org/r/20160621154601.GA22431@cmpxchg.org
Fixes: b2052564e6 ("mm: memcontrol: continue cache reclaim from offlined groups")
Link: http://lkml.kernel.org/r/20160617162516.GD19084@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: John Garcia <john.garcia@mesosphere.io>
Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Nikolay Borisov <kernel@kyup.com>
Cc: <stable@vger.kernel.org>	[3.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-23 10:25:54 +09:00
..
kasan kasan/quarantine: fix bugs on qlist_move_cache() 2016-07-15 14:54:27 +09:00
backing-dev.c mm: throttle on IO only when there are too many dirty and writeback pages 2016-05-20 17:58:30 -07:00
balloon_compaction.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2016-03-17 21:38:27 -07:00
bootmem.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
cleancache.c cleancache: constify cleancache_ops structure 2016-01-27 09:09:57 -05:00
cma_debug.c mm/cma_debug: correct size input to bitmap function 2015-07-17 16:39:54 -07:00
cma.c mm/cma: silence warnings due to max() usage 2016-05-27 14:49:37 -07:00
cma.h mm: cma: mark cma_bitmap_maxno() inline in header 2015-08-14 15:56:32 -07:00
compaction.c mm, compaction: prevent VM_BUG_ON when terminating freeing scanner 2016-07-15 14:54:27 +09:00
debug_page_ref.c mm/page_ref: add tracepoint to track down page reference manipulation 2016-03-17 15:09:34 -07:00
debug.c mm: introduce page reference manipulation functions 2016-03-17 15:09:34 -07:00
dmapool.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
early_ioremap.c mm/early_ioremap: use offset_in_page macro 2015-11-05 19:34:48 -08:00
fadvise.c mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED 2016-06-09 14:23:11 -07:00
failslab.c mm: fault-inject take over bootstrap kmem_cache check 2016-03-15 16:55:16 -07:00
filemap.c Revert "mm: make faultaround produce old ptes" 2016-06-24 17:23:52 -07:00
frame_vector.c mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
frontswap.c frontswap: allow multiple backends 2015-06-24 17:49:45 -07:00
gup.c Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-04-14 19:31:34 -07:00
highmem.c mm/highmem: make nr_free_highpages() handles all highmem zones by itself 2016-05-19 19:12:14 -07:00
huge_memory.c mm: thp: move pmd check inside ptl for freeze_page() 2016-07-15 14:54:27 +09:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
hugetlb.c mm: thp: refix false positive BUG in page_move_anon_rmap() 2016-07-15 14:54:27 +09:00
hwpoison-inject.c hwpoison: use page_cgroup_ino for filtering by memcg 2015-09-10 13:29:01 -07:00
init-mm.c
internal.h mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask 2016-06-24 17:23:52 -07:00
interval_tree.c mm: replace vma->sharead.linear with vma->shared 2015-02-10 14:30:31 -08:00
Kconfig mm: disable DEFERRED_STRUCT_PAGE_INIT on !NO_BOOTMEM 2016-05-27 14:49:37 -07:00
Kconfig.debug mm/page_ref: add tracepoint to track down page reference manipulation 2016-03-17 15:09:34 -07:00
kmemcheck.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak-test.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak.c mm: prevent KASAN false positives in kmemleak 2016-06-24 17:23:52 -07:00
ksm.c ksm: fix conflict between mmput and scan_get_next_rmap_item 2016-05-12 15:52:50 -07:00
list_lru.c mm: memcontrol: move kmem accounting code to CONFIG_MEMCG 2016-01-20 17:09:18 -08:00
maccess.c x86: remove more uaccess_32.h complexity 2016-05-22 17:21:27 -07:00
madvise.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
Makefile z3fold: the 3-fold allocator for compressed pages 2016-05-20 17:58:30 -07:00
memblock.c mm/memblock.c: remove unnecessary always-true comparison 2016-05-20 17:58:30 -07:00
memcontrol.c mm: memcontrol: fix cgroup creation failure after many small jobs 2016-07-23 10:25:54 +09:00
memory_hotplug.c mm: fix section mismatch warning 2016-05-27 15:23:32 -07:00
memory-failure.c mm/memory-failure.c: replace "MCE" with "Memory failure" 2016-05-20 17:58:30 -07:00
memory.c mm: thp: refix false positive BUG in page_move_anon_rmap() 2016-07-15 14:54:27 +09:00
mempolicy.c mm, page_alloc: avoid looking up the first zone in a zonelist twice 2016-05-19 19:12:14 -07:00
mempool.c mm: mempool: kasan: don't poot mempool objects in quarantine 2016-06-24 17:23:52 -07:00
memtest.c memtest: remove unused header files 2015-09-08 15:35:28 -07:00
migrate.c mm: Export migrate_page_move_mapping and migrate_page_copy 2016-06-23 00:29:45 +02:00
mincore.c mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage 2016-04-04 10:41:08 -07:00
mlock.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
mm_init.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
mmap.c mm: remove more IS_ERR_VALUE abuses 2016-05-27 15:57:31 -07:00
mmu_context.c mm/mmu_context, sched/core: Fix mmu_context.h assumption 2016-04-28 11:44:19 +02:00
mmu_notifier.c fix Christoph's email addresses 2016-03-17 15:09:34 -07:00
mmzone.c mm, page_alloc: inline the fast path of the zonelist iterator 2016-05-19 19:12:14 -07:00
mprotect.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
mremap.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
msync.c mm/msync: use offset_in_page macro 2015-11-05 19:34:48 -08:00
nobootmem.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
nommu.c mm: remove more IS_ERR_VALUE abuses 2016-05-27 15:57:31 -07:00
oom_kill.c oom_reaper: avoid pointless atomic_inc_not_zero usage. 2016-06-24 17:23:52 -07:00
page_alloc.c mm, meminit: ensure node is online before checking whether pages are uninitialised 2016-07-15 14:54:27 +09:00
page_counter.c mm: page_counter: let page_counter_try_charge() return bool 2015-11-05 19:34:48 -08:00
page_ext.c mm: use early_pfn_to_nid in page_ext_init 2016-05-27 14:49:37 -07:00
page_idle.c mm: add page_check_address_transhuge() helper 2016-01-15 17:56:32 -08:00
page_io.c Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-17 15:05:23 -07:00
page_isolation.c mm/memory_hotplug: add comment to some functions related to memory hotplug 2016-05-19 19:12:14 -07:00
page_owner.c mm/page_owner: avoid null pointer dereference 2016-06-24 17:23:52 -07:00
page_poison.c mm: check the return value of lookup_page_ext for all call sites 2016-06-03 15:06:22 -07:00
page-writeback.c writeback: use higher precision calculation in domain_dirty_limits() 2016-05-30 08:54:40 -06:00
pagewalk.c thp: rename split_huge_page_pmd() to split_huge_pmd() 2016-01-15 17:56:32 -08:00
percpu-km.c mm: percpu: use pr_fmt to prefix output 2016-03-17 15:09:34 -07:00
percpu-vm.c percpu: move region iterations out of pcpu_[de]populate_chunk() 2014-09-02 14:46:02 -04:00
percpu.c percpu: fix synchronization between synchronous map extension and chunk destruction 2016-05-25 11:48:25 -04:00
pgtable-generic.c mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range 2016-03-17 15:09:34 -07:00
process_vm_access.c mm/gup: Introduce get_user_pages_remote() 2016-02-16 10:04:09 +01:00
quicklist.c fix Christoph's email addresses 2016-03-17 15:09:34 -07:00
readahead.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
rmap.c mm: thp: refix false positive BUG in page_move_anon_rmap() 2016-07-15 14:54:27 +09:00
shmem.c tmpfs: fix regression hang in fallocate undo 2016-07-10 20:08:44 -07:00
slab_common.c mm: memcontrol: fix cgroup creation failure after many small jobs 2016-07-23 10:25:54 +09:00
slab.c mm, kasan: don't call kasan_krealloc() from ksize(). 2016-05-20 17:58:30 -07:00
slab.h mm: kasan: initial memory quarantine implementation 2016-05-20 17:58:30 -07:00
slob.c mm: slab: free kmem_cache_node after destroy sysfs file 2016-02-18 16:23:24 -08:00
slub.c mm, kasan: don't call kasan_krealloc() from ksize(). 2016-05-20 17:58:30 -07:00
sparse-vmemmap.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
sparse.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
swap_cgroup.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
swap_state.c mm: thp: broken page count after commit aa88b68c3b 2016-06-09 14:23:11 -07:00
swap.c mm/swap.c: flush lru pvecs on compound page arrival 2016-06-24 17:23:52 -07:00
swapfile.c mm: thp: calculate the mapcount correctly for THP pages during WP faults 2016-05-12 15:52:50 -07:00
truncate.c dax: New fault locking 2016-05-19 15:20:54 -06:00
userfaultfd.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
util.c mm: make vm_mmap killable 2016-05-23 17:04:14 -07:00
vmacache.c mm/vmacache: inline vmacache_valid_mm() 2015-11-05 19:34:48 -08:00
vmalloc.c mm: fix overflow in vm_map_ram() 2016-06-03 15:06:22 -07:00
vmpressure.c mm/vmpressure.c: fix subtree pressure detection 2016-02-03 08:28:43 -08:00
vmscan.c mm, oom: rework oom detection 2016-05-20 17:58:30 -07:00
vmstat.c mm: check the return value of lookup_page_ext for all call sites 2016-06-03 15:06:22 -07:00
workingset.c mm: workingset: printk missing log level, use pr_info() 2016-07-15 14:54:27 +09:00
z3fold.c mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup 2016-06-03 16:02:55 -07:00
zbud.c mm/zbud.c: use list_last_entry() instead of list_tail_entry() 2016-01-15 11:40:52 -08:00
zpool.c mm: zsmalloc: constify struct zs_pool name 2015-11-06 17:50:42 -08:00
zsmalloc.c update "mm/zsmalloc: don't fail if can't create debugfs info" 2016-05-26 15:35:44 -07:00
zswap.c mm/zswap: use workqueue to destroy pool 2016-05-20 17:58:30 -07:00