From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9CFC6C433DF for ; Wed, 14 Oct 2020 21:25:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46EAB221FF for ; Wed, 14 Oct 2020 21:25:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727878AbgJNVZD (ORCPT ); Wed, 14 Oct 2020 17:25:03 -0400 Received: from mail104.syd.optusnet.com.au ([211.29.132.246]:54423 "EHLO mail104.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726484AbgJNVZD (ORCPT ); Wed, 14 Oct 2020 17:25:03 -0400 Received: from dread.disaster.area (pa49-195-69-88.pa.nsw.optusnet.com.au [49.195.69.88]) by mail104.syd.optusnet.com.au (Postfix) with ESMTPS id 4CE5E58C1E4; Thu, 15 Oct 2020 08:24:59 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1kSoGY-000YyK-Mh; Thu, 15 Oct 2020 08:24:58 +1100 Date: Thu, 15 Oct 2020 08:24:58 +1100 From: Dave Chinner To: Wang Yugui Cc: linux-xfs@vger.kernel.org Subject: Re: dbench throughput on xfs over hardware limit(6Gb/s) Message-ID: <20201014212458.GC7391@dread.disaster.area> References: <20201013221113.F0A0.409509F4@e16-tech.com> <20201013230521.GB7391@dread.disaster.area> <20201014113211.2372.409509F4@e16-tech.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201014113211.2372.409509F4@e16-tech.com> X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=YKPhNiOx c=1 sm=1 tr=0 cx=a_idp_d a=5g0Hk5519kQvxAqikqd8LA==:117 a=5g0Hk5519kQvxAqikqd8LA==:17 a=kj9zAlcOel0A:10 a=afefHYAZSVUA:10 a=7-415B0cAAAA:8 a=83GoWlhbdbGG2EoRCkMA:9 a=mtGRwOJSVpvi1bqE:21 a=oaFyXoszcu-ZlxHt:21 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Wed, Oct 14, 2020 at 11:32:11AM +0800, Wang Yugui wrote: > > > On Tue, Oct 13, 2020 at 10:11:13PM +0800, Wang Yugui wrote: > > > Hi, > > > > > > dbench throughput on xfs over hardware limit(6Gb/s=750MB/s). > > > > > > Is this a bug or some feature of performance optimization? > > > > dbench measures page cache throughput, not physical IO throughput. > > This sort of results is expected. > > We use 'dbench -s', so it should be physical IO. > -s Use synchronous file IO on all file operations. Reads can still be served from the page cache without doing physical IO. Cheers, Dave. -- Dave Chinner david@fromorbit.com