On Thu 29-08-19 13:31:10, Shakeel Butt wrote:

Instead of using raw_cpu_read() use per_cpu() to read the actual data of the corresponding cpu otherwise we will be reading the data of the current cpu for the number of online CPUs.

Fixes: bb65f89b7d3d ("mm: memcontrol: flush percpu vmevents before releasing memcg") Fixes: c350a99ea2b1 ("mm: memcontrol: flush percpu vmstats before releasing memcg") Signed-off-by: Shakeel Butt shakeelb@google.com Cc: Roman Gushchin guro@fb.com Cc: Michal Hocko mhocko@suse.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Vladimir Davydov vdavydov.dev@gmail.com Cc: Andrew Morton akpm@linux-foundation.org Cc: stable@vger.kernel.org

Ups, missed that when reviewing. Sorry about that.

Acked-by: Michal Hocko mhocko@suse.com

---

Note: The buggy patches were marked for stable therefore adding Cc to stable.

mm/memcontrol.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 26e2999af608..f4e60ee8b845 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3271,7 +3271,7 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) for_each_online_cpu(cpu) for (i = 0; i < MEMCG_NR_STAT; i++)

• 	stat[i] += raw_cpu_read(memcg->vmstats_percpu->stat[i]);
  

• 	stat[i] += per_cpu(memcg->vmstats_percpu->stat[i], cpu);
  

for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) for (i = 0; i < MEMCG_NR_STAT; i++) @@ -3286,8 +3286,8 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg) for_each_online_cpu(cpu) for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)

• 		stat[i] += raw_cpu_read(
  

• 			pn->lruvec_stat_cpu->count[i]);
  

• 		stat[i] += per_cpu(
  

• 			pn->lruvec_stat_cpu->count[i], cpu);
  

for (pi = pn; pi; pi = parent_nodeinfo(pi, node)) for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) @@ -3306,8 +3306,8 @@ static void memcg_flush_percpu_vmevents(struct mem_cgroup *memcg) for_each_online_cpu(cpu) for (i = 0; i < NR_VM_EVENT_ITEMS; i++)

• 	events[i] += raw_cpu_read(
  

• 		memcg->vmstats_percpu->events[i]);
  

• 	events[i] += per_cpu(memcg->vmstats_percpu->events[i],
  

• 			     cpu);
  

for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) for (i = 0; i < NR_VM_EVENT_ITEMS; i++) -- 2.23.0.187.g17f5b7556c-goog