From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754791AbZHCLoa (ORCPT ); Mon, 3 Aug 2009 07:44:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754521AbZHCLo3 (ORCPT ); Mon, 3 Aug 2009 07:44:29 -0400 Received: from fg-out-1718.google.com ([72.14.220.159]:26709 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752937AbZHCLo2 convert rfc822-to-8bit (ORCPT ); Mon, 3 Aug 2009 07:44:28 -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=m1Ropjs042ioxEFmJhZrbduv4Umr7GZvjbnoNH7wUo4SlsB4d7tHYbZ8gYQ13sdN72 qYsq1OT4SyJFrmFXTHaiSThzQqkdsjREpsPHmEB54qDeJYNTOvNXy6Np0NuRrsUEWVXT JKWzy2jven8Etsr5IFwOj5AuTihd7HFRSeN2I= MIME-Version: 1.0 In-Reply-To: <4A76ABD5.9020808@vlnb.net> References: <4A3CD62B.1020407@vlnb.net> <4A641AAC.9030300@vlnb.net> <4A6DA77B.7080600@vlnb.net> <4A6F4C81.10600@vlnb.net> <4A7338AF.8010407@vlnb.net> <4A76ABD5.9020808@vlnb.net> Date: Mon, 3 Aug 2009 13:44:28 +0200 Message-ID: Subject: Re: [RESEND] [PATCH] readahead:add blk_run_backing_dev From: Ronald Moesbergen To: Vladislav Bolkhovitin Cc: fengguang.wu@intel.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, Alan.Brunelle@hp.com, 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: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2009/8/3 Vladislav Bolkhovitin : > Ronald Moesbergen, on 08/03/2009 01:15 PM wrote: >> >> 2009/7/31 Vladislav Bolkhovitin : >>> >>> OK, as I expected, on the SCST level everything is clear and the forced >>> ordering change didn't change anything. >>> >>> But still, a single read stream must be the fastest from single thread. >>> Otherwise, there's something wrong somewhere in the I/O path: block >>> layer, >>> RA, I/O scheduler. And, apparently, this is what we have and should find >>> out >>> the cause. >>> >>> Can you check if noop on the target and/or initiator makes any >>> difference? >>> Case 5 with 1 and 2 threads will be sufficient. >> >> That doesn't seem to help: >> >> client kernel: 2.6.26-15lenny3 (debian) >> server kernel: 2.6.29.5 with readahead-context, blk_run_backing_dev >> and io_context, forced_order >> >> With one IO thread: >> 5) client: default, server: default (server noop, client noop) >> blocksize       R        R        R   R(avg,    R(std        R >>  (bytes)     (s)      (s)      (s)    MB/s)   ,MB/s)   (IOPS) >>  67108864  17.612   21.113   21.355   51.532    4.680    0.805 >>  33554432  18.329   18.523   19.049   54.969    0.891    1.718 >>  16777216  18.497   18.219   17.042   57.217    2.059    3.576 >> >> With two threads: >> 5) client: default, server: default (server noop, client noop) >> blocksize       R        R        R   R(avg,    R(std        R >>  (bytes)     (s)      (s)      (s)    MB/s)   ,MB/s)   (IOPS) >>  67108864  17.436   18.376   20.493   54.807    3.634    0.856 >>  33554432  17.466   16.980   18.261   58.337    1.740    1.823 >>  16777216  18.222   17.567   18.077   57.045    0.901    3.565 > > And with client cfq, server noop? client kernel: 2.6.26-15lenny3 (debian) server kernel: 2.6.29.5 with readahead-context, blk_run_backing_dev and io_context, forced_order With one IO thread: 5) client: default, server: default (server noop, client cfq) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 16.019 16.434 15.730 63.777 1.144 0.997 33554432 16.020 16.624 15.936 63.258 1.183 1.977 16777216 15.966 15.465 16.115 64.630 1.145 4.039 With two threads: 5) client: default, server: default (server noop, client cfq) blocksize R R R R(avg, R(std R (bytes) (s) (s) (s) MB/s) ,MB/s) (IOPS) 67108864 16.504 15.762 14.842 65.335 2.848 1.021 33554432 16.080 16.627 15.766 63.406 1.386 1.981 16777216 15.489 16.627 16.043 63.842 1.846 3.990 Ronald.