diff options
| author | Yang Shi | 2019-08-03 06:48:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2019-08-06 19:06:54 +0200 |
| commit | beb0cc781b8e07d4bf89b6be2bf6e7ff7fe8b7ff (patch) | |
| tree | c3aa160f117a86615f55ed6ff9929e3056d82860 /mm | |
| parent | ALSA: hda: Fix 1-minute detection delay when i915 module is not available (diff) | |
| download | kernel-qcow2-linux-beb0cc781b8e07d4bf89b6be2bf6e7ff7fe8b7ff.tar.gz kernel-qcow2-linux-beb0cc781b8e07d4bf89b6be2bf6e7ff7fe8b7ff.tar.xz kernel-qcow2-linux-beb0cc781b8e07d4bf89b6be2bf6e7ff7fe8b7ff.zip | |
mm: vmscan: check if mem cgroup is disabled or not before calling memcg slab shrinker
commit fa1e512fac717f34e7c12d7a384c46e90a647392 upstream.
Shakeel Butt reported premature oom on kernel with
"cgroup_disable=memory" since mem_cgroup_is_root() returns false even
though memcg is actually NULL. The drop_caches is also broken.
It is because commit aeed1d325d42 ("mm/vmscan.c: generalize
shrink_slab() calls in shrink_node()") removed the !memcg check before
!mem_cgroup_is_root(). And, surprisingly root memcg is allocated even
though memory cgroup is disabled by kernel boot parameter.
Add mem_cgroup_disabled() check to make reclaimer work as expected.
Link: http://lkml.kernel.org/r/1563385526-20805-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: aeed1d325d42 ("mm/vmscan.c: generalize shrink_slab() calls in shrink_node()")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reported-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jan Hadrava <had@kam.mff.cuni.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/vmscan.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/mm/vmscan.c b/mm/vmscan.c index 576379e87421..b37610c0eac6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -670,7 +670,14 @@ static unsigned long shrink_slab(gfp_t gfp_mask, int nid, unsigned long ret, freed = 0; struct shrinker *shrinker; - if (!mem_cgroup_is_root(memcg)) + /* + * The root memcg might be allocated even though memcg is disabled + * via "cgroup_disable=memory" boot parameter. This could make + * mem_cgroup_is_root() return false, then just run memcg slab + * shrink, but skip global shrink. This may result in premature + * oom. + */ + if (!mem_cgroup_disabled() && !mem_cgroup_is_root(memcg)) return shrink_slab_memcg(gfp_mask, nid, memcg, priority); if (!down_read_trylock(&shrinker_rwsem)) |