From: Johannes Weiner <jweiner@redhat.com>
Date: Fri, 13 Jan 2012 01:18:45 +0000 (-0800)
Subject: mm: memcg: remove unneeded checks from uncharge_page()
X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=40f23a21a8501c1b2c65c50c19b516488ac31313;p=~shefty%2Frdma-dev.git

mm: memcg: remove unneeded checks from uncharge_page()

mem_cgroup_uncharge_page() is only called on either freshly allocated
pages without page->mapping or on rmapped PageAnon() pages.  There is no
need to check for a page->mapping that is not an anon_vma.

Signed-off-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.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 2450d89486d..71a9774e6ea 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3061,8 +3061,7 @@ void mem_cgroup_uncharge_page(struct page *page)
 	/* early check. */
 	if (page_mapped(page))
 		return;
-	if (page->mapping && !PageAnon(page))
-		return;
+	VM_BUG_ON(page->mapping && !PageAnon(page));
 	__mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_MAPPED);
 }