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| author | Muchun Song <songmuchun@bytedance.com> | 2021-02-24 21:04:22 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-02-24 22:38:30 +0100 |
| commit | 1685bde6b9af55923180a76152036c7fb7176db0 (patch) | |
| tree | 611edd8bd93c5ef712ec0b18f6c79b34fd4ca75d /mm/memcontrol.c | |
| parent | mm: memcontrol: fix swap undercounting in cgroup2 (diff) | |
| download | linux-1685bde6b9af55923180a76152036c7fb7176db0.tar.xz linux-1685bde6b9af55923180a76152036c7fb7176db0.zip | |
mm: memcontrol: fix get_active_memcg return value
We use a global percpu int_active_memcg variable to store the remote memcg
when we are in the interrupt context. But get_active_memcg always return
the current->active_memcg or root_mem_cgroup. The remote memcg (set in
the interrupt context) is ignored. This is not what we want. So fix it.
Link: https://lkml.kernel.org/r/20210223091101.42150-1-songmuchun@bytedance.com
Fixes: 37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/memcontrol.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 2db2aeac8a9e..845eec01ef9d 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1061,13 +1061,9 @@ static __always_inline struct mem_cgroup *get_active_memcg(void) rcu_read_lock(); memcg = active_memcg(); - if (memcg) { - /* current->active_memcg must hold a ref. */ - if (WARN_ON_ONCE(!css_tryget(&memcg->css))) - memcg = root_mem_cgroup; - else - memcg = current->active_memcg; - } + /* remote memcg must hold a ref. */ + if (memcg && WARN_ON_ONCE(!css_tryget(&memcg->css))) + memcg = root_mem_cgroup; rcu_read_unlock(); return memcg; |