From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263928AbUFCT43 (ORCPT ); Thu, 3 Jun 2004 15:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264205AbUFCT43 (ORCPT ); Thu, 3 Jun 2004 15:56:29 -0400 Received: from c7ns3.center7.com ([216.250.142.14]:20967 "EHLO smtp.slc03.viawest.net") by vger.kernel.org with ESMTP id S263928AbUFCT41 (ORCPT ); Thu, 3 Jun 2004 15:56:27 -0400 Message-ID: <40BFBAA1.4080301@drdos.com> Date: Thu, 03 Jun 2004 17:56:17 -0600 From: "Jeff V. Merkey" User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linus Torvalds Cc: Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: submit_bh leaves interrupts on upon return References: <40BE93DC.6040501@drdos.com> <20040603085002.GG28915@suse.de> <40BF8E1F.1060009@drdos.com> <20040603165250.GO1946@suse.de> <40BF9124.6080807@drdos.com> <20040603170328.GQ1946@suse.de> In-Reply-To: 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 Linus Torvalds wrote: >On Thu, 3 Jun 2004, Jens Axboe wrote: > > > >>On Thu, Jun 03 2004, Jeff V. Merkey wrote: >> >> >>>Sounds like I need to move to 2.6. I noticed the elevator is coalescing >>>quite well, and since I am posting mostly continguous runs of sectors, >>>what ends up at the adapter level would probably not change much much >>>between 2.4 and 2.6 since I am maxing out the driver request queues as >>>it is (255 pending requests of 32 scatter/gather elements of 256 sector >>>runs). 2.6 might help but I suspect it will only help alleviate the >>>submission overhead, and not make much difference on performance since >>>the 3Ware card does have an upward limit on outstanding I/O requests. >>> >>> >>That's correct, it just helps you diminish the submission overhead by >>pushing down 256 sector entities in one go. So as long as you're io >>bound it won't give you better io performance, of course. If you are >>doing 400MiB/sec it should help you out, though. >> >> > >Well, if Jeff does almost exclusively contiguous stuff and submits them in >order, then the coalescing will make sure that even on 2.4.x the queues >don't get too long, and he probably won't see the pathological cases. > > Linus >- > Linus, This seems to be the case. Jeff >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/ > > >