From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751075AbWA2Qit (ORCPT ); Sun, 29 Jan 2006 11:38:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751076AbWA2Qit (ORCPT ); Sun, 29 Jan 2006 11:38:49 -0500 Received: from stat9.steeleye.com ([209.192.50.41]:30856 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S1751071AbWA2Qir (ORCPT ); Sun, 29 Jan 2006 11:38:47 -0500 Subject: Re: memory leak in scsi_cmd_cache 2.6.15 From: James Bottomley To: Pasi =?ISO-8859-1?Q?K=E4rkk=E4inen?= Cc: Jens Axboe , Nix , Ariel , Jamie Heilman , Chase Venters , Arjan van de Ven , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org In-Reply-To: <20060129155009.GT28738@edu.joroinen.fi> References: <1137997104.2977.7.camel@laptopd505.fenrus.org> <200601230029.12674.chase.venters@clientec.com> <20060123072556.GC15490@fifty-fifty.audible.transient.net> <87ek2td4i9.fsf@amaterasu.srvr.nix> <20060128192714.GI9750@suse.de> <20060129155009.GT28738@edu.joroinen.fi> Content-Type: text/plain; charset=ISO-8859-1 Date: Sun, 29 Jan 2006 10:38:12 -0600 Message-Id: <1138552692.3352.6.camel@mulgrave> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2006-01-29 at 17:50 +0200, Pasi Kärkkäinen wrote: > Are all sata drivers affected by this bug in 2.6.15? Well, all SCSI drivers are affected by it, yes. However, SATA devices are peculiarly affected because the ordered_flush method of enforcing barriers, which is where the leak is, can only be implemented for devices that don't do tag command queueing (i.e. don't have multiple commands outstanding for a given single device). By and large, SATA drivers are the only drivers in the SCSI subsystem that can't do tag command queueing, which is why the problem didn't show up for any other type of SCSI driver. > Any 'official' patch available? Well, yes, 2.6.16-rc1 has this fixed. I can't see backporting this to 2.6.15.x since it represents a significant functionality enhancement as well, so I'd lean towards just forcing ordered_flush to zero in 2.6.15.x which seems to be the best bug fix. > Or is the recommended workaround to set ordered_flush to 0 to fix this.. > does that have any downsides? setting ordered_flush to zero for 2.6.15 turns off the flushing functionality and restores the old behaviour. I don't see that there would be any down side to this. James