From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264819AbUETAx1 (ORCPT ); Wed, 19 May 2004 20:53:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264820AbUETAx0 (ORCPT ); Wed, 19 May 2004 20:53:26 -0400 Received: from ozlabs.org ([203.10.76.45]:9346 "EHLO ozlabs.org") by vger.kernel.org with ESMTP id S264819AbUETAxZ (ORCPT ); Wed, 19 May 2004 20:53:25 -0400 Subject: Re: [PATCH] Remove bogus WARN_ON in futex_wait From: Rusty Russell To: Andi Kleen Cc: Muli Ben-Yehuda , lkml - Kernel Mailing List , Andrew Morton In-Reply-To: <20040519125001.3866f830.ak@suse.de> References: <20040519122350.2792e050.ak@suse.de> <20040519104339.GG31630@mulix.org> <20040519125001.3866f830.ak@suse.de> Content-Type: text/plain Message-Id: <1085013927.7624.5.camel@bach> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Thu, 20 May 2004 10:52:46 +1000 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2004-05-19 at 20:50, Andi Kleen wrote: > On Wed, 19 May 2004 13:43:40 +0300 > Muli Ben-Yehuda wrote: > > > On Wed, May 19, 2004 at 12:23:50PM +0200, Andi Kleen wrote: > > > > > > futex_wait goes to an interruptible sleep, but does a WARN_ON later > > > if it wakes up early. But waking up early is totally legal, since > > > the sleep is interruptible and any signal can wake it up. > > > > That's not what the WARN_ON is saynig, unless I'm missing > > something. It's checking if we were woken up early and there's no > > signal pending for us. > > True. Anyways, it seems to happen in practice. Which we've been trying to figure out. We return -EINTR in this case even though it's a lie. Don't know if it breaks anything, but I *really* want to know who the buggy waker is before pronouncing it harmless. Rusty. -- Anyone who quotes me in their signature is an idiot -- Rusty Russell