From: "Rafael J. Wysocki" <rjw@sisk.pl>
To: Oleg Nesterov <oleg@tv-sign.ru>
Subject: Re: [PATCH] fix refrigerator() vs thaw_process() race
Date: Mon, 19 Feb 2007 00:28:03 +0100
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Cc: Andrew Morton <akpm@linux-foundation.org>, Pavel Machek <pavel@ucw.cz>,
       "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
       linux-kernel@vger.kernel.org
References: <20070218221737.GA4880@tv-sign.ru>
In-Reply-To: <20070218221737.GA4880@tv-sign.ru>
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On Sunday, 18 February 2007 23:17, Oleg Nesterov wrote:
> refrigerator() can miss a wakeup, "wait event" loop needs a proper memory
> ordering.
> 
> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>

ACK 

> --- WQ/kernel/power/process.c~WAKE	2007-02-18 22:56:49.000000000 +0300
> +++ WQ/kernel/power/process.c	2007-02-19 01:04:26.000000000 +0300
> @@ -46,8 +46,10 @@ void refrigerator(void)
>  	recalc_sigpending(); /* We sent fake signal, clean it up */
>  	spin_unlock_irq(&current->sighand->siglock);
>  
> -	while (frozen(current)) {
> -		current->state = TASK_UNINTERRUPTIBLE;
> +	for (;;) {
> +		set_current_state(TASK_UNINTERRUPTIBLE);
> +		if (!frozen(current))
> +			break;
>  		schedule();
>  	}
>  	pr_debug("%s left refrigerator\n", current->comm);
> 
> 
> 

-- 
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you don't have the time or the tools to write.
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