Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030312AbVKPNMf (ORCPT ); Wed, 16 Nov 2005 08:12:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965250AbVKPNMf (ORCPT ); Wed, 16 Nov 2005 08:12:35 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:4896 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S965042AbVKPNMe (ORCPT ); Wed, 16 Nov 2005 08:12:34 -0500 Date: Wed, 16 Nov 2005 14:13:33 +0100 From: Jens Axboe To: Jeff Garzik Cc: Mike Christie , Tejun Heo , linux-ide@vger.kernel.org, lkml , SCSI Mailing List Subject: Re: [PATCH] libata error handling fixes (ATAPI) Message-ID: <20051116131333.GA7787@suse.de> References: <20051114195717.GA24373@havoc.gtf.org> <20051115074148.GA17459@htj.dyndns.org> <4379AA5B.1060900@pobox.com> <4379B28E.9070708@gmail.com> <4379C062.3010302@pobox.com> <20051115120016.GD7787@suse.de> <437A2814.1060308@cs.wisc.edu> <20051115184131.GJ7787@suse.de> <20051116124035.GX7787@suse.de> <437B2C61.7080605@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <437B2C61.7080605@pobox.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1235 Lines: 33 On Wed, Nov 16 2005, Jeff Garzik wrote: > Jens Axboe wrote: > >I updated that patch, and converted IDE and SCSI to use it. See the > >results here: > > > >http://brick.kernel.dk/git/?p=linux-2.6-block.git;a=shortlog;h=blk-softirq > > > >The main change from the version posted last october is killing the > >'slightly' overdesigned completion queue hashing. > > Nifty, I like. Comments: > > * use of spin_lock_irq() in all completion paths now makes me nervous. Should be fine from the paths originating from blk_done_softirq(), as we know interrupts are enabled in the first place. But generally I agree, whenever in doubt always always use the irq saving variants. > * certainly it's what SCSI does now, but is a softirq really necessary? > Using a tasklet would kill all that per-cpu code, and notifier. It would work fine with a tasklet of course, but it's going to generate a _lot_ of traffic on io busy systems so I felt a dedicated softirq was the way to go. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/