From 3c1da7beeee02560cd0f0c66c5a59fce3c6746e3 Mon Sep 17 00:00:00 2001
From: Vladimir Davydov <vdavydov@virtuozzo.com>
Date: Tue, 2 Feb 2016 16:57:49 -0800
Subject: [PATCH] mm/vmpressure.c: fix subtree pressure detection
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>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
mm/vmpressure.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index 9a6c0704211c8..149fdf6c5c56f 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)
--
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