From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754792AbYCHVj2 (ORCPT ); Sat, 8 Mar 2008 16:39:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751858AbYCHVjO (ORCPT ); Sat, 8 Mar 2008 16:39:14 -0500 Received: from webaccess-cl.virtdom.com ([216.240.101.25]:61791 "EHLO webaccess-cl.virtdom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753664AbYCHVip (ORCPT ); Sat, 8 Mar 2008 16:38:45 -0500 Date: Sat, 8 Mar 2008 11:38:27 -1000 (HST) From: Jeff Roberson X-X-Sender: jroberson@desktop To: Davide Libenzi cc: Rik van Riel , Linux Kernel Mailing List , Zach Brown Subject: Re: [PATCH] eventfd signal race in aio_complete() In-Reply-To: Message-ID: <20080308113744.J1091@desktop> References: <20080307161854.E920@desktop> <20080308102321.4527372e@bree.surriel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 8 Mar 2008, Davide Libenzi wrote: > On Sat, 8 Mar 2008, Rik van Riel wrote: > >> On Fri, 7 Mar 2008 20:29:20 -0800 (PST) >> Davide Libenzi wrote: >> >>> The second solution/patch simply moves the eventfd_signal() call before >>> the __aio_put_req() call, but after the event has beed "ringed". >>> We should be clear to go with the shorter/nicer second solution. Those >>> patches builds, but I'm not even signing them off till I tested them. >> >> If there are no spinlock ordering issues between &ctx->ctx_lock >> and &ctx->wqh.lock (taken inside eventfd_signal), then the second >> patch is indeed preferable. >> >> Jeff and I did look at that briefly last night, but were not >> familiar enough with the code to decide whether or not that was >> safe. > > There's no interlocking between the two, so let's go with #2. > Jeff, would you mind giving patch #2 a spin in your test suite? I agree #2 would be best as well. It may take me a few days due to some equipment issues but I will get back to you as soon as I can. Thanks, Jeff > > > > - Davide > >