Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755703AbZGMMrf (ORCPT ); Mon, 13 Jul 2009 08:47:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755562AbZGMMre (ORCPT ); Mon, 13 Jul 2009 08:47:34 -0400 Received: from fg-out-1718.google.com ([72.14.220.157]:35408 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755461AbZGMMrd (ORCPT ); Mon, 13 Jul 2009 08:47:33 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=oYIqHaRgzEyG/hJhPtqWnpnvPkDhafH04ahWVp1+T1I9fNgf1/Sp/Uf81eEfEzjWYB UFqXoQzLaJAPEahdUTzAsHhi7Fe4VHWVZf6xEBrlXZjzdluEdP17ju+oEVgWCFy+bMfo bCGBcQwOypW5Z/a7b3jVIFYhNrPq37SZuWXJ4= MIME-Version: 1.0 In-Reply-To: <20090713123621.GA31051@localhost> References: <4A5395FD.2040507@vlnb.net> <4A5493A8.2000806@vlnb.net> <4A56FF32.2060303@vlnb.net> <4A570981.5080803@vlnb.net> <20090713123621.GA31051@localhost> Date: Mon, 13 Jul 2009 14:47:31 +0200 Message-ID: Subject: Re: [RESEND] [PATCH] readahead:add blk_run_backing_dev From: Ronald Moesbergen To: Wu Fengguang Cc: Vladislav Bolkhovitin , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "kosaki.motohiro@jp.fujitsu.com" , "Alan.Brunelle@hp.com" , "hifumi.hisashi@oss.ntt.co.jp" , "linux-fsdevel@vger.kernel.org" , "jens.axboe@oracle.com" , "randy.dunlap@oracle.com" , Bart Van Assche Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1814 Lines: 50 2009/7/13 Wu Fengguang : > On Mon, Jul 13, 2009 at 08:12:14PM +0800, Ronald Moesbergen wrote: >> 2009/7/10 Vladislav Bolkhovitin : >> > >> > Vladislav Bolkhovitin, on 07/10/2009 12:43 PM wrote: >> >> >> >> Ronald Moesbergen, on 07/10/2009 10:32 AM wrote: >> >>>> >> >>>> I've also long ago noticed that reading data from block devices is >> >>>> slower >> >>>> than from files from mounted on those block devices file systems. Can >> >>>> anybody explain it? >> >>>> >> >>>> Looks like this is strangeness #2 which we uncovered in our tests (the >> >>>> first >> >>>> one was earlier in this thread why the context RA doesn't work with >> >>>> cooperative I/O threads as good as it should). >> >>>> >> >>>> Can you rerun the same 11 tests over a file on the file system, please? >> >>> >> >>> I'll see what I can do. Just te be sure: you want me to run >> >>> blockdev-perftest on a file on the OCFS2 filesystem which is mounted >> >>> on the client over iScsi, right? >> >> >> >> Yes, please. >> > >> > Forgot to mention that you should also configure your backend storage as a >> > big file on a file system (preferably, XFS) too, not as direct device, like >> > /dev/vg/db-master. >> >> Ok, here are the results: > > Ronald, thanks for the numbers! You're welcome. >> client kernel: 2.6.26-15lenny3 (debian) >> server kernel: 2.6.29.5 with readahead patch > > Do you mean the context readahead patch? No, I meant the blk_run_backing_dev patch. The patchnames are confusing, I'll be sure to clarify them from now on. Ronald. -- 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/