Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755397AbXABROp (ORCPT ); Tue, 2 Jan 2007 12:14:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755393AbXABROo (ORCPT ); Tue, 2 Jan 2007 12:14:44 -0500 Received: from tmailer.gwdg.de ([134.76.10.23]:56192 "EHLO tmailer.gwdg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755390AbXABROn (ORCPT ); Tue, 2 Jan 2007 12:14:43 -0500 Date: Tue, 2 Jan 2007 18:09:17 +0100 (MET) From: Jan Engelhardt To: Mark Lord cc: Jens Axboe , Rene Herman , Tejun Heo , Alan Cox , linux-kernel@vger.kernel.org, Linus Torvalds Subject: Re: 2.6.20-rc2+: CFQ halving disk throughput. In-Reply-To: <459A73CB.8010901@rtr.ca> Message-ID: References: <45893CAD.9050909@gmail.com> <45921E73.1080601@gmail.com> <4592B25A.4040906@gmail.com> <45932AF1.9040900@gmail.com> <45998F62.6010904@gmail.com> <4599992D.8000607@rtr.ca> <20070102083414.GQ2483@kernel.dk> <459A73CB.8010901@rtr.ca> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Spam-Report: Content analysis: 0.0 points, 6.0 required _SUMMARY_ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 994 Lines: 33 On Jan 2 2007 10:01, Mark Lord wrote: > Jens Axboe wrote: >> >> > But surely one of (not sure which) sync+async or async+sync may also >> > be okay? >> > Or would it? >> >> Async merge to sync request should be ok. But I wonder what happens with >> hdparm, since it seems to trigger one of these tests. Very puzzling. >> I'll dive in and take a look. > > The code (written 10 years ago) isn't the best in the world, > and will be redone entirely for hdparm-7.0 this year. > > But right now, it essentially does this: > > loop: > seek( to sector zero ); > read( 2MBytes ); > repeat loop for 3 seconds Well for pure reading speed, I already use dd_rescue -d /dev/hda /dev/null Gives the same as hdparm -t when acting on uncached data. -`J' -- - 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/