From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754835AbZFADGz (ORCPT ); Sun, 31 May 2009 23:06:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754102AbZFADGq (ORCPT ); Sun, 31 May 2009 23:06:46 -0400 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:48434 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753954AbZFADGp (ORCPT ); Sun, 31 May 2009 23:06:45 -0400 From: KOSAKI Motohiro To: Wu Fengguang Subject: Re: [PATCH] readahead:add blk_run_backing_dev Cc: kosaki.motohiro@jp.fujitsu.com, Hisashi Hifumi , Andrew Morton , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , "jens.axboe@oracle.com" In-Reply-To: <20090601030249.GA10348@localhost> References: <6.0.0.20.2.20090601115104.0739dac0@172.19.0.2> <20090601030249.GA10348@localhost> Message-Id: <20090601120524.4F5A.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Mon, 1 Jun 2009 12:06:44 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > >> >I mean, you should get >300MB/s throughput with 7 disks, and you > > >> >should seek ways to achieve that before testing out this patch :-) > > >> > > >> Throughput number of storage array is very from one product to another. > > >> On my hardware environment I think this number is valid and > > >> my patch is effective. > > > > > >What's your readahead size? Is it large enough to cover the stripe width? > > > > Do you mean strage's readahead size? > > What's strage? I mean if your RAID's block device file is /dev/sda, then I guess it's typo :-) but I recommend he use sane test environment... > > blockdev --getra /dev/sda > > will tell its readahead size in unit of 512 bytes. > > Thanks, > Fengguang >