From 1d4a788f15302877ff2cb08f22009e290a36a209 Mon Sep 17 00:00:00 2001
From: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Date: Fri, 28 Mar 2008 14:15:50 -0700
Subject: [PATCH] memcgroup: fix spurious EBUSY on memory cgroup removal

Call mm_free_cgroup earlier.  Otherwise a reference due to lazy mm switching
can prevent cgroup removal.

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 kernel/fork.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index dd249c37b3a3..9c042f901570 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -394,7 +394,6 @@ void __mmdrop(struct mm_struct *mm)
 {
 	BUG_ON(mm == &init_mm);
 	mm_free_pgd(mm);
-	mm_free_cgroup(mm);
 	destroy_context(mm);
 	free_mm(mm);
 }
@@ -416,6 +415,7 @@ void mmput(struct mm_struct *mm)
 			spin_unlock(&mmlist_lock);
 		}
 		put_swap_token(mm);
+		mm_free_cgroup(mm);
 		mmdrop(mm);
 	}
 }
-- 
2.20.1