From 38d384932ed1b58f0ed8dd17c66e0cd89acb354a Mon Sep 17 00:00:00 2001
From: Shakeel Butt <shakeelb@google.com>
Date: Thu, 11 Jul 2019 20:55:48 -0700
Subject: [PATCH] memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL

The documentation of __GFP_RETRY_MAYFAIL clearly mentioned that the OOM
killer will not be triggered and indeed the page alloc does not invoke OOM
killer for such allocations.  However we do trigger memcg OOM killer for
__GFP_RETRY_MAYFAIL.  Fix that.  This flag will used later to not trigger
oom-killer in the charging path for fanotify and inotify event
allocations.

Link: http://lkml.kernel.org/r/20190514212259.156585-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 mm/memcontrol.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 591eafafbd8c..2ad94d0ce22f 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2279,7 +2279,6 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	unsigned long nr_reclaimed;
 	bool may_swap = true;
 	bool drained = false;
-	bool oomed = false;
 	enum oom_status oom_status;
 
 	if (mem_cgroup_is_root(memcg))
@@ -2366,7 +2365,7 @@ retry:
 	if (nr_retries--)
 		goto retry;
 
-	if (gfp_mask & __GFP_RETRY_MAYFAIL && oomed)
+	if (gfp_mask & __GFP_RETRY_MAYFAIL)
 		goto nomem;
 
 	if (gfp_mask & __GFP_NOFAIL)
@@ -2385,7 +2384,6 @@ retry:
 	switch (oom_status) {
 	case OOM_SUCCESS:
 		nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
-		oomed = true;
 		goto retry;
 	case OOM_FAILED:
 		goto force;