memcg: remove NULL check from lookup_page_cgroup() result
The page_cgroup array is set up before even fork is initialized. I
seriously doubt that this code executes before the array is alloc'd.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b94cd24..3a2d54b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2369,10 +2369,7 @@
}
pc = lookup_page_cgroup(page);
- /* can happen at boot */
- if (unlikely(!pc))
- return 0;
- prefetchw(pc);
+ BUG_ON(!pc); /* XXX: remove this and move pc lookup into commit */
ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, oom, page_size);
if (ret || !mem)