mm, memcg: avoid unnecessary function call when memcg is disabled
authorDavid Rientjes <rientjes@google.com>
Wed, 12 Dec 2012 21:51:57 +0000 (13:51 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 13 Dec 2012 01:38:34 +0000 (17:38 -0800)
commit68ae564bbac8eb9ed54ddd2529b0e29ee190b355
tree5cef83b5fa072f62091552457e7d0319ce170b98
parent05b0afd73d04109d87f00ccd39f099e217c37263
mm, memcg: avoid unnecessary function call when memcg is disabled

While profiling numa/core v16 with cgroup_disable=memory on the command
line, I noticed mem_cgroup_count_vm_event() still showed up as high as
0.60% in perftop.

This occurs because the function is called extremely often even when memcg
is disabled.

To fix this, inline the check for mem_cgroup_disabled() so we avoid the
unnecessary function call if memcg is disabled.

Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Glauber Costa <glommer@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/memcontrol.h
mm/memcontrol.c