From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750862AbWIMOXZ (ORCPT ); Wed, 13 Sep 2006 10:23:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750863AbWIMOXZ (ORCPT ); Wed, 13 Sep 2006 10:23:25 -0400 Received: from mxsf25.cluster1.charter.net ([209.225.28.225]:10955 "EHLO mxsf25.cluster1.charter.net") by vger.kernel.org with ESMTP id S1750861AbWIMOXY (ORCPT ); Wed, 13 Sep 2006 10:23:24 -0400 X-IronPort-AV: i="4.09,160,1157342400"; d="scan'208"; a="680093774:sNHT160548710" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <17672.5209.158911.963437@smtp.charter.net> Date: Wed, 13 Sep 2006 10:23:21 -0400 From: "John Stoffel" To: Al Boldi Cc: Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: What's in linux-2.6-block.git In-Reply-To: <200609131435.31390.a1426z@gawab.com> References: <200609131359.04972.a1426z@gawab.com> <20060913105932.GA4792@kernel.dk> <200609131435.31390.a1426z@gawab.com> X-Mailer: VM 7.19 under Emacs 21.4.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Al" == Al Boldi writes: Al> Jens Axboe wrote: >> On Wed, Sep 13 2006, Al Boldi wrote: >> > Jens Axboe wrote: >> > > This lists the main features of the 'block' branch, which is bound for >> > > Linus when 2.6.19 opens: >> > > >> > > - Splitting of request->flags into two parts: >> > > - cmd type >> > > - modified flags >> > > Right now it's a bit of a mess, splitting this up invites a cleaner >> > > usage and also enables us to implement generic "messages" passed on >> > > the regular queue for the device. >> > > >> > > - Abstract out the request back merging and put it into the core io >> > > scheduler layer. Cleans up all the io schedulers, and noop gets >> > > merging for "free". >> > > >> > > - Abstract out the rbtree sorting. Gets rid of duplicated code in >> > > as/cfq/deadline. >> > > >> > > - General shrinkage of the request structure. >> > > >> > > - Killing dynamic rq private structures in deadline/as/cfq. This >> > > should speed up the io path somewhat, as we avoid allocating several >> > > structures (struct request + scheduler private request) for each io >> > > request. >> > > >> > > - meta data io logging for blktrace. >> > > >> > > - CFQ improvements. >> > > >> > > - Make the block layer configurable through Kconfig (David Howells). >> > > >> > > - Lots of cleanups. >> > >> > Does it also address the strange "max_sectors_kb<>192 causes a >> > 50%-slowdown" problem? >> >> (remember to cc me/others when replying, I can easily miss lkml >> messages for several days otherwise). >> >> It does not, the investigation of that is still pending I'm afraid. The >> data is really puzzling, I'm inclined to think it's drive related. Are >> you reproducing it just one box/drive, or on several? Al> Several boxes, same drive. Al> /dev/hda: Al> ATA device, with non-removable media Al> Model Number: WDC WD1200JB-00DUA0 Al> Serial Number: WD-WMACM1007651 Al> Firmware Revision: 65.13G65 Al> Standards: Al> Supported: 6 5 4 3 Al> Likely used: 6 I've got a pair of drives which are very close in model type, and I can run some non-destructive tests on them if you like to confirm what's going on here if you like: /dev/hde: ATA device, with non-removable media Model Number: WDC WD1200JB-00CRA1 Serial Number: WD-WMA8C4365875 Firmware Revision: 17.07W17 Standards: Supported: 5 4 3 Likely used: 6 jfsnew:~> sudo hdparm -I /dev/hdg | head /dev/hdg: ATA device, with non-removable media Model Number: WDC WD1200JB-00EVA0 Serial Number: WD-WMAEK2844058 Firmware Revision: 15.05R15 Standards: Supported: 6 5 4 Likely used: 6 The drives have different defaul max_sectors too: > cat /sys/block/hdg/queue/max_sectors_kb 512 > cat /sys/block/hde/queue/max_sectors_kb 128 Let me know your test method and I'll run it here and post the results. John