From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264669AbUETInN (ORCPT ); Thu, 20 May 2004 04:43:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265006AbUETInN (ORCPT ); Thu, 20 May 2004 04:43:13 -0400 Received: from cantor.suse.de ([195.135.220.2]:48330 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S264669AbUETInK (ORCPT ); Thu, 20 May 2004 04:43:10 -0400 Date: Thu, 20 May 2004 10:41:43 +0200 From: Andi Kleen To: Rusty Russell Cc: mulix@mulix.org, linux-kernel@vger.kernel.org, akpm@osdl.org Subject: Re: [PATCH] Remove bogus WARN_ON in futex_wait Message-Id: <20040520104143.6830f81b.ak@suse.de> In-Reply-To: <1085013927.7624.5.camel@bach> References: <20040519122350.2792e050.ak@suse.de> <20040519104339.GG31630@mulix.org> <20040519125001.3866f830.ak@suse.de> <1085013927.7624.5.camel@bach> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 20 May 2004 10:52:46 +1000 Rusty Russell wrote: > 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. e.g. from ptrace, like Daniel said. I don't think it was from ptrace in the case where I saw a report, but it shows that the WARN_ON is bogus. If you really want to know what causes it you would need more debugging code as Nick pointed out too. So, the WARN_ON in its current form is known to trigger in a valid situation and not sufficient to find possible problems. I would remove it. -Andi