1. 31 Aug, 2019 1 commit
    • Roman Gushchin's avatar
      mm: memcontrol: flush percpu slab vmstats on kmem offlining · bee07b33
      Roman Gushchin authored
      I've noticed that the "slab" value in memory.stat is sometimes 0, even
      if some children memory cgroups have a non-zero "slab" value.  The
      following investigation showed that this is the result of the kmem_cache
      reparenting in combination with the per-cpu batching of slab vmstats.
      
      At the offlining some vmstat value may leave in the percpu cache, not
      being propagated upwards by the cgroup hierarchy.  It means that stats
      on ancestor levels are lower than actual.  Later when slab pages are
      released, the precise number of pages is substracted on the parent
      level, making the value negative.  We don't show negative values, 0 is
      printed instead.
      
      To fix this issue, let's flush percpu slab memcg and lruvec stats on
      memcg offlining.  This guarantees that numbers on all ancestor levels
      are accurate and match the actual number of outstanding slab pages.
      
      Link: http://lkml.kernel.org/r/20190819202338.363363-3-guro@fb.com
      Fixes: fb2f2b0a ("mm: memcg/slab: reparent memcg kmem_caches on cgroup removal")
      Signed-off-by: default avatarRoman Gushchin <guro@fb.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Michal Hocko <mhocko@kernel.org>
      Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      bee07b33
  2. 30 Aug, 2019 17 commits
  3. 29 Aug, 2019 8 commits
  4. 28 Aug, 2019 6 commits
  5. 27 Aug, 2019 8 commits