[Devel] [PATCH RESEND 08/11] slab: do not panic if we fail to create memcg cache

[Vladimir Davydov]

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 at parallels.com>
Cc: Michal Hocko <mhocko at suse.cz>
Cc: Glauber Costa <glommer at gmail.com>
Cc: Johannes Weiner <hannes at cmpxchg.org>
Cc: Pekka Enberg <penberg at kernel.org>
Cc: Christoph Lameter <cl at linux.com>
Cc: Andrew Morton <akpm at linux-foundation.org>
---
 mm/slab_common.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/mm/slab_common.c b/mm/slab_common.c
index f34707e..8e40321 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);
-- 
1.7.10.4