sched/core: Remove false-positive warning from wake_up_process()

sashalevin · Ingo Molnar · commit 119d6f6a3be8 · 2015-12-04T10:10:16.000+01:00
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@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: oleg@redhat.com Fixes: 9067ac8 ("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@kernel.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
@@ -2039,7 +2039,6 @@ static void try_to_wake_up_local(struct task_struct *p)
  */
 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);

Original file line number	Diff line number	Diff line change
`@@ -2039,7 +2039,6 @@ static void try_to_wake_up_local(struct task_struct *p)`
`2039`	`2039`	`*/`
`2040`	`2040`	`int wake_up_process(struct task_struct *p)`
`2041`	`2041`	`{`
`2042`		`- WARN_ON(task_is_stopped_or_traced(p));`
`2043`	`2042`	`return try_to_wake_up(p, TASK_NORMAL, 0);`
`2044`	`2043`	`}`
`2045`	`2044`	`EXPORT_SYMBOL(wake_up_process);`