Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759720AbZF2On5 (ORCPT ); Mon, 29 Jun 2009 10:43:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752714AbZF2Ont (ORCPT ); Mon, 29 Jun 2009 10:43:49 -0400 Received: from mail-ew0-f210.google.com ([209.85.219.210]:40707 "EHLO mail-ew0-f210.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752276AbZF2Onr (ORCPT ); Mon, 29 Jun 2009 10:43:47 -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=jx3PkXWfEWNn3NmiWYNsePDWIaAMM+wjjEju8/VZ0Y4Dhh3cMUbtEsk2GLYSpFKT1P EkLXOPWcKmu80QHANTY1gBvMAGni9zDqv3od7sHKbUTB3HMDX+BBcvhkMC26kjZrGn+9 eoNlFQBDmEd35i9CKlRe+QHwj1RrPwSVjfDYU= MIME-Version: 1.0 In-Reply-To: <20090629132841.GA26171@localhost> References: <20090606224538.GA6173@localhost> <20090620035504.GA19516@localhost> <4A3CD62B.1020407@vlnb.net> <20090629093423.GB1315@localhost> <4A489DAC.7000007@vlnb.net> <20090629125434.GA8416@localhost> <4A48BBF9.6050408@vlnb.net> <20090629131326.GA23668@localhost> <20090629132841.GA26171@localhost> Date: Mon, 29 Jun 2009 16:43:48 +0200 Message-ID: Subject: Re: [RESEND] [PATCH] readahead:add blk_run_backing_dev From: Ronald Moesbergen To: Wu Fengguang Cc: Vladislav Bolkhovitin , Andrew Morton , "kosaki.motohiro@jp.fujitsu.com" , "Alan.Brunelle@hp.com" , "hifumi.hisashi@oss.ntt.co.jp" , "linux-kernel@vger.kernel.org" , "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: 1466 Lines: 33 2009/6/29 Wu Fengguang : > On Mon, Jun 29, 2009 at 09:13:27PM +0800, Wu Fengguang wrote: >> On Mon, Jun 29, 2009 at 09:04:57PM +0800, Vladislav Bolkhovitin wrote: >> > Wu Fengguang, on 06/29/2009 04:54 PM wrote: >> > > >> > > Why not 2.6.30? :) >> > >> > We started with 2.6.29, so why not complete with it (to save additional >> > Ronald's effort to move on 2.6.30)? >> >> OK, that's fair enough. > > btw, I backported the 2.6.31 context readahead patches to 2.6.29, just > in case it will help the SCST performance. > > Ronald, if you run context readahead, please make sure that the server > side readahead size is bigger than the client side readahead size. I tried this patch on a vanilla kernel and no other patches applied, but it does not seem to help. The iSCSI throughput does not go above 60MB/s. (1GB in 17 seconds). I have tried several readahead settings from 128KB up to 4MB and kept the server readahead at twice the client readahead, but it never comes above 60MB/s. This is using SCST on the serverside and openiscsi on the client. I get much better throughput (90 MB/s) when using the patches supplied with SCST, together with the blk_run_backing_dev readahead patch. 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/