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: ce6b59abbaa8 ("mm: memcontrol: flush percpu vmevents before releasing memcg")
Fixes: 412ac8b533e6 ("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 a247cb1632453cbaae8b7f977d20a1faff0eee55..9ec5e12486a7805c8250f9a814be5036785c66b1 100644 (file)
--- 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++)