From: Vladimir Davydov <vdavydov@parallels.com>
Date: Thu, 23 Jan 2014 23:53:05 +0000 (-0800)
Subject: slab: do not panic if we fail to create memcg cache
X-Git-Tag: firefly_0821_release~176^2~4584^2~180
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f717eb3abb5ea38f60e671dbfdbf512c2c93d22e;p=firefly-linux-kernel-4.4.55.git

slab: do not panic if we fail to create memcg cache

There is no point in flooding logs with warnings or especially crashing
the system if we fail to create a cache for a memcg.  In this case we
will be accounting the memcg allocation to the root cgroup until we
succeed to create its own cache, but it isn't that critical.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/slab_common.c b/mm/slab_common.c
index f34707eeacc7..8e40321da091 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -233,7 +233,14 @@ out_unlock:
 	mutex_unlock(&slab_mutex);
 	put_online_cpus();
 
-	if (err) {
+	/*
+	 * There is no point in flooding logs with warnings or especially
+	 * crashing the system if we fail to create a cache for a memcg. In
+	 * this case we will be accounting the memcg allocation to the root
+	 * cgroup until we succeed to create its own cache, but it isn't that
+	 * critical.
+	 */
+	if (err && !memcg) {
 		if (flags & SLAB_PANIC)
 			panic("kmem_cache_create: Failed to create slab '%s'. Error %d\n",
 				name, err);