From 11f34787b50ce71f66b85ad8790beaa5eee3f897 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Thu, 12 Sep 2013 15:13:42 -0700
Subject: mm: memcg: enable memcg OOM killer only for user faults

commit 519e52473ebe9db5cdef44670d5a97f1fd53d721 upstream.

System calls and kernel faults (uaccess, gup) can handle an out of memory
situation gracefully and just return -ENOMEM.

Enable the memcg OOM killer only for user faults, where it's really the
only option available.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/sched.h | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'include/linux/sched.h')

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f87e9a8d364f..42a58ce480bc 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1411,6 +1411,9 @@ struct task_struct {
 		unsigned long memsw_nr_pages; /* uncharged mem+swap usage */
 	} memcg_batch;
 	unsigned int memcg_kmem_skip_account;
+	struct memcg_oom_info {
+		unsigned int may_oom:1;
+	} memcg_oom;
 #endif
 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 	atomic_t ptrace_bp_refcnt;
-- 
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