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From: tip-bot for Sasha Levin <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: torvalds@linux-foundation.org, hpa@zytor.com,
	sasha.levin@oracle.com, linux-kernel@vger.kernel.org,
	peterz@infradead.org, efault@gmx.de, mingo@kernel.org,
	tglx@linutronix.de
Subject: [tip:locking/core] sched/core: Remove false-positive warning from wake_up_process()
Date: Fri, 4 Dec 2015 03:52:32 -0800	[thread overview]
Message-ID: <tip-119d6f6a3be8b424b200dcee56e74484d5445f7e@git.kernel.org> (raw)
In-Reply-To: <1448933660-23082-1-git-send-email-sasha.levin@oracle.com>

Commit-ID:  119d6f6a3be8b424b200dcee56e74484d5445f7e
Gitweb:     http://git.kernel.org/tip/119d6f6a3be8b424b200dcee56e74484d5445f7e
Author:     Sasha Levin <sasha.levin@oracle.com>
AuthorDate: Mon, 30 Nov 2015 20:34:20 -0500
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 4 Dec 2015 10:10:16 +0100

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

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: 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@kernel.org>
---
 kernel/sched/core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4d568ac..fc8c987 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2039,7 +2039,6 @@ 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);

      parent reply	other threads:[~2015-12-04 11:53 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-01  1:34 [PATCH] sched: remove false-positive warning from wake_up_process() Sasha Levin
2015-12-01  1:47 ` Linus Torvalds
2015-12-01  2:48   ` Rik van Riel
2015-12-01  3:14     ` Linus Torvalds
2015-12-03 12:36 ` Peter Zijlstra
2015-12-03 18:18   ` Linus Torvalds
2015-12-04 11:52 ` tip-bot for Sasha Levin [this message]

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