[patch 122/126] mm: memcontrol: remove BUG_ON in uncharge_list

[patch 122/126] mm: memcontrol: remove BUG_ON in uncharge_list

[akpm]

From: Li RongQing <roy.qing.li@gmail.com>
Subject: mm: memcontrol: remove BUG_ON in uncharge_list

When calling uncharge_list, if a page is transparent huge we don't need to
BUG_ON about non-transparent huge, since nobody should be able to see the
page at this stage and this page cannot be raced against with a THP split.

This check became unneeded after 0a31bc97c80c ("mm: memcontrol: rewrite
uncharge API").

[mhocko@suse.com: changelog enhancements]
Link: http://lkml.kernel.org/r/1465369248-13865-1-git-send-email-roy.qing.li@gmail.com
Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    1 -
 1 file changed, 1 deletion(-)

diff -puN mm/memcontrol.c~mm-memcontrol-remove-bug_on-in-uncharge_list mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcontrol-remove-bug_on-in-uncharge_list
+++ a/mm/memcontrol.c
@@ -5580,7 +5580,6 @@ static void uncharge_list(struct list_he
 
 			if (PageTransHuge(page)) {
 				nr_pages <<= compound_order(page);
-				VM_BUG_ON_PAGE(!PageTransHuge(page), page);
 				nr_huge += nr_pages;
 			}
 			if (PageAnon(page))
_