The patch below does not apply to the 5.2-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 6c1c280805ded72eceb2afc1a0d431b256608554 Mon Sep 17 00:00:00 2001
From: Shakeel Butt shakeelb@google.com Date: Fri, 30 Aug 2019 16:04:53 -0700 Subject: [PATCH] mm: memcontrol: fix percpu vmstats and vmevents flush
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.
Link: http://lkml.kernel.org/r/20190829203110.129263-1-shakeelb@google.com 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 Acked-by: Roman Gushchin guro@fb.com Acked-by: Michal Hocko mhocko@suse.com Cc: Johannes Weiner hannes@cmpxchg.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
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index a247cb163245..9ec5e12486a7 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3278,7 +3278,7 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg, bool slab_only)
for_each_online_cpu(cpu) for (i = min_idx; i < max_idx; 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 = min_idx; i < max_idx; i++) @@ -3296,8 +3296,8 @@ static void memcg_flush_percpu_vmstats(struct mem_cgroup *memcg, bool slab_only)
for_each_online_cpu(cpu) for (i = min_idx; i < max_idx; 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 = min_idx; i < max_idx; i++) @@ -3316,8 +3316,8 @@ 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++)