From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262538AbUDTKyL (ORCPT ); Tue, 20 Apr 2004 06:54:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262580AbUDTKyK (ORCPT ); Tue, 20 Apr 2004 06:54:10 -0400 Received: from mx1.redhat.com ([66.187.233.31]:17377 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262538AbUDTKyG (ORCPT ); Tue, 20 Apr 2004 06:54:06 -0400 Message-ID: <40850143.1090709@redhat.com> Date: Tue, 20 Apr 2004 00:53:55 -1000 From: Warren Togami User-Agent: Mozilla Thunderbird 0.5 (X11/20040418) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Jens Axboe CC: Markus Lidel , Arjan van de Ven , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Alan Cox Subject: Re: [PATCH] i2o_block Fix, possible CFQ elevator problem? References: <4083BA03.1090606@redhat.com> <20040419121225.GT1966@suse.de> <408471E2.8060201@redhat.com> <40848159.7090605@togami.com> <20040420070805.GC25806@suse.de> <4084D83D.8060405@redhat.com> <20040420080325.GD25806@suse.de> <4084E671.4090509@redhat.com> <20040420090523.GE25806@suse.de> In-Reply-To: <20040420090523.GE25806@suse.de> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe wrote: >>>Not necessarily, it's most likely a CFQ bug. Otherwise it would have >>>surfaced before :-) >>> >> >>I forgot to mention in the previous reports: >> >>Prior to three of your original suggested cleanups of i2o_block, four >>simultaneous bonnie++'s on four independent arrays would almost >>immediately cause the crash while running elevator=cfq. After those >>three cleanups four simultaneous bonnie++ would survive for a while >>without crashing... until you run "sync" in another terminal. We >>however did not test it enough times to determine if without "sync" it >>can survive the test run. Do you want this tested without "sync"? > > > Repeat the tests that made it crash. The last patch I sent should work > for you, at least until the real issue is found. > Tested your patch, it indeed does seem to keep the system stable. If I am understanding it right, the patch disables merging in the case where it would have caused a BUG condition? (Less efficiency.) In any case, for now we are doing our i2o development using the other schedulers like deadline. Let us know if you have updated cfq patches to try, and we will. Warren Togami wtogami@redhat.com