Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754007AbZGJJ1u (ORCPT ); Fri, 10 Jul 2009 05:27:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751907AbZGJJ1k (ORCPT ); Fri, 10 Jul 2009 05:27:40 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:63768 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751455AbZGJJ1j (ORCPT ); Fri, 10 Jul 2009 05:27:39 -0400 Message-ID: <4A570981.5080803@vlnb.net> Date: Fri, 10 Jul 2009 13:27:29 +0400 From: Vladislav Bolkhovitin User-Agent: Thunderbird 2.0.0.21 (X11/20090320) MIME-Version: 1.0 To: Ronald Moesbergen CC: fengguang.wu@intel.com, 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 Subject: Re: [RESEND] [PATCH] readahead:add blk_run_backing_dev References: <4A3CD62B.1020407@vlnb.net> <4A4DE3C1.5080307@vlnb.net> <4A51DC0A.10302@vlnb.net> <4A5238EC.1070505@vlnb.net> <4A5395FD.2040507@vlnb.net> <4A5493A8.2000806@vlnb.net> <4A56FF32.2060303@vlnb.net> In-Reply-To: <4A56FF32.2060303@vlnb.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V01U2FsdGVkX18PAlt+ZTWLajFCvGmL0K5MUcoHg7xXqpW4YQQ qlrzD/EVdKzNo09v0R6+MDK2695rpNQO1WgXqnGLjxdZNUB4/y Uf1bD1mfF6LWdmSkyeMVQ== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1191 Lines: 30 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. Thanks, Vlad -- 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/