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Date: Sun, 15 Jul 2007 19:39:14 +0400
From: Oleg Nesterov <oleg@tv-sign.ru>
To: Ingo Molnar <mingo@elte.hu>, Mike Galbraith <efault@gmx.de>
Cc: linux-kernel@vger.kernel.org
Subject: Q: a bogus task_running() check in try_to_wake_up() ?
Message-ID: <20070715153914.GA441@tv-sign.ru>
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try_to_wake_up:
	
	if (p->se.on_rq)
		goto out_running;

	...

	if (unlikely(task_running(rq, p)))
		goto out_activate;

How it possible that rq->curr has on_rq == 0 ?

AFAICS, this can only happen if this task is rq->idle. But idle threads
should not sleep, we have a special "scheduling from the idle thread!"
check in schedule().

Thanks in advance,

Oleg.