From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oleg Nesterov <oleg@tv-sign.ru>
Subject: Re: [RFC][PATCH -mm 4/7] Freezer: Introduce
	freezer-firendly waiting macros
Date: Thu, 12 Jul 2007 03:02:49 +0400
Message-ID: <20070711230249.GA310@tv-sign.ru>
References: <200707120006.50095.rjw@sisk.pl> <200707120013.32672.rjw@sisk.pl>
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To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>, pm list <linux-pm@lists.linux-foundation.org>, Pavel Machek <pavel@ucw.cz>, Miklos Szeredi <miklos@szeredi.hu>
List-Id: linux-pm@vger.kernel.org

On 07/12, Rafael J. Wysocki wrote:
>
> +#define wait_event_freezable(wq, condition)				\
> +({									\
> +	int __ret;							\
> +	do {								\
> +		__ret = wait_event_interruptible(wq, 			\
> +				(condition) || freezing(current));	\
> +		try_to_freeze();					\
> +	} while (!(condition));					\
> +	__ret;								\
> +})

This is still not right in general, I believe.

It will spin if the caller is signalled. You changed the freezer, but
kthread can use signals anyway.

It returns only when "condition" is true, so the "__ret" is meaningless.

Oleg.