[PATCH] vmpressure: Fix subtree pressure detection

Vladimir Davydov
2016-01-27T16:29:09Z

When vmpressure is called for the entire subtree under pressure we
mistakenly use vmpressure->scanned instead of vmpressure->tree_scanned
when checking if vmpressure work is to be scheduled. This results in
suppressing all vmpressure events in the legacy cgroup hierarchy. Fix
it.

Fixes: 8e8ae645249b ("mm: memcontrol: hook up vmpressure to socket pressure")
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
---
mm/vmpressure.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 9a6c0704211c..149fdf6c5c56 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -248,9 +248,8 @@ void vmpressure(gfp_t gfp, struct mem_cgroup *memcg, bool tree,

if (tree) {
spin_lock(&vmpr->sr_lock);
- vmpr->tree_scanned += scanned;
+ scanned = vmpr->tree_scanned += scanned;
vmpr->tree_reclaimed += reclaimed;
- scanned = vmpr->scanned;
spin_unlock(&vmpr->sr_lock);

if (scanned < vmpressure_win)
--
2.1.4