From 97ae19821c638183a533583eb4668da9127bd0a7 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Thu, 22 Oct 2015 09:03:11 +1100
Subject: [PATCH] 
 mm-oom_kill-fix-the-wrong-task-mm-==-mm-checks-in-oom_kill_process-fix

document process_shares_mm() a bit

Cc: David Rientjes <rientjes@google.com>
Cc: Kyle Walker <kwalker@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Stanislav Kozina <skozina@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/oom_kill.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 52abb78633d5..d13a33918fa2 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -483,6 +483,12 @@ void oom_killer_enable(void)
 	oom_killer_disabled = false;
 }
 
+/*
+ * task->mm can be NULL if the task is the exited group leader.  So to
+ * determine whether the task is using a particular mm, we examine all the
+ * task's threads: if one of those is using this mm then this task was also
+ * using it.
+ */
 static bool process_shares_mm(struct task_struct *p, struct mm_struct *mm)
 {
 	struct task_struct *t;
-- 
2.39.5