Date: Sun, 27 Jul 2008 09:51:53 -0700 (PDT)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Oleg Nesterov <oleg@tv-sign.ru>
cc: akpm@linux-foundation.org, roland@redhat.com, mingo@elte.hu,
       linux-kernel@vger.kernel.org
Subject: Re: Q: wait_task_inactive() and !CONFIG_SMP && CONFIG_PREEMPT
In-Reply-To: <20080727121540.GB178@tv-sign.ru>
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References: <200807260245.m6Q2jwB4012297@imap1.linux-foundation.org> <20080727121540.GB178@tv-sign.ru>
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On Sun, 27 Jul 2008, Oleg Nesterov wrote:
>
> Without CONFIG_SMP wait_task_inactive() is noop, this doesn't look right.
> Shouldn't we also take CONFIG_PREEMPT into account?

The exit path had _better_ be non-preemptable until it hits the final 
schedule that disables it (and that wait_task_inactive() was waiting for). 
At least that used to be the rule.

Of course, historically the only user for this was just the "wait for 
exit to complete" case. And that isn't really true any more, I guess. So I 
dunno.

		Linus
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