[PATCH 3.19.y-ckt 123/128] sched/core: Remove false-positive warning from wake_up_process()

[Kamal Mostafa]

3.19.8-ckt12 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sasha Levin <sasha.levin at oracle.com>

commit 119d6f6a3be8b424b200dcee56e74484d5445f7e upstream.

Because wakeups can (fundamentally) be late, a task might not be in
the expected state. Therefore testing against a task's state is racy,
and can yield false positives.

Signed-off-by: Sasha Levin <sasha.levin at oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Acked-by: Linus Torvalds <torvalds at linux-foundation.org>
Cc: Mike Galbraith <efault at gmx.de>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: oleg at redhat.com
Fixes: 9067ac85d533 ("wake_up_process() should be never used to wakeup a TASK_STOPPED/TRACED task")
Link: http://lkml.kernel.org/r/1448933660-23082-1-git-send-email-sasha.levin@oracle.com
Signed-off-by: Ingo Molnar <mingo at kernel.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 kernel/sched/core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 2006f4f..6b5909b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1812,7 +1812,6 @@ out:
  */
 int wake_up_process(struct task_struct *p)
 {
-	WARN_ON(task_is_stopped_or_traced(p));
 	return try_to_wake_up(p, TASK_NORMAL, 0);
 }
 EXPORT_SYMBOL(wake_up_process);
-- 
1.9.1