2019-07-17 12:31:17

by Konstantin Khlebnikov

Subject: [PATCH 1/2] mm/memcontrol: fix flushing per-cpu counters in memcg_hotplug_cpu_dead

Use correct memcg pointer.

Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
Signed-off-by: Konstantin Khlebnikov <[email protected]>
---
mm/memcontrol.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 249671873aa9..06d33dfc4ec4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2259,7 +2259,7 @@ static int memcg_hotplug_cpu_dead(unsigned int cpu)
x = this_cpu_xchg(memcg->vmstats_percpu->stat[i], 0);
if (x)
for (mi = memcg; mi; mi = parent_mem_cgroup(mi))
- atomic_long_add(x, &memcg->vmstats[i]);
+ atomic_long_add(x, &mi->vmstats[i]);

if (i >= NR_VM_NODE_STAT_ITEMS)
continue;
@@ -2282,7 +2282,7 @@ static int memcg_hotplug_cpu_dead(unsigned int cpu)
x = this_cpu_xchg(memcg->vmstats_percpu->events[i], 0);
if (x)
for (mi = memcg; mi; mi = parent_mem_cgroup(mi))
- atomic_long_add(x, &memcg->vmevents[i]);
+ atomic_long_add(x, &mi->vmevents[i]);
}
}

2019-07-17 17:37:09

by Johannes Weiner

Subject: Re: [PATCH 1/2] mm/memcontrol: fix flushing per-cpu counters in memcg_hotplug_cpu_dead

On Wed, Jul 17, 2019 at 03:29:17PM +0300, Konstantin Khlebnikov wrote:
> Use correct memcg pointer.
>
> Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
> Signed-off-by: Konstantin Khlebnikov <[email protected]>

Oops, nice catch.

Acked-by: Johannes Weiner <[email protected]>