memcgroup: remove a useless VM_BUG_ON()

Remove this VM_BUG_ON(), as Balbir stated:

We used to have a for loop with !list_empty() as a termination condition
and VM_BUG_ON(!pc) is a spill over.  With the new loop, VM_BUG_ON(!pc) does
not make sense.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Balbir Singh <balbir@in.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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 6bded84c20c88b7b4687a2954f31509ef1527c0d..bb4d7acfbca3fc0177b213c86db6caf9ad41cf12 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -534,7 +534,6 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                if (scan >= nr_to_scan)
                        break;
                page = pc->page;
-               VM_BUG_ON(!pc);
 
                if (unlikely(!PageLRU(page)))
                        continue;