From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 8FAD67F37 for ; Thu, 7 May 2015 17:55:29 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id 813A830404E for ; Thu, 7 May 2015 15:55:26 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id g4aq2NEY1VZxkiuy for ; Thu, 07 May 2015 15:55:23 -0700 (PDT) Date: Fri, 8 May 2015 08:55:21 +1000 From: Dave Chinner Subject: Re: Valid Benchmark Value & Methods Message-ID: <20150507225521.GB16689@dastard> References: <554B4B59.6000706@xtremenitro.org> <2204700.QypQcg3ER3@merkaba> <554B5782.4040303@xtremenitro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <554B5782.4040303@xtremenitro.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dewangga Cc: xfs@oss.sgi.com On Thu, May 07, 2015 at 07:16:02PM +0700, Dewangga wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hello Martin, > Thanks for your reply, yes I've read that link, but another question, > is noatime,nodiratime,etc still valid for performance tuning guidance? You may have read it, but I don't think it sunk in.... > Even the default mount options only "rw,inode64,seclabel,attr2". Where's relatime(*)? That's been a default for a lot longer than inode64... $ grep "root " /proc/mounts /dev/root / xfs rw,relatime,attr2,inode64,noquota 0 0 $ > Is it still increase the performance if the additional mount options > added? Depends on your workload, which is more critical to understand than anything else. Why? because it's your workload that is going to determine if twiddling a knob is going to have any effect on performance. Once you understand the workload and what the bottlenecks are, then you can look at what knobs the filesystem provides to alleviate those bottlenecks. IOWs, asking the question "how do I tune my filesystem for best performance" is, fundamentally, the wrong way to go about obtaining best filesystem performance. The questions that need to be answered are "what bottlenecks does my application have?" followed by "what does the filesystem provide to alleviate those bottlenecks". i.e. understand the problem you need to solve *before* you try to solve it, otherwise you "solve" the wrong problem... Cheers, Dave. (*) An example of exactly what I'm talking abou there. The default option of relatime gets >95% of the benefit of noatime onmost workloads compared to the old strictatime behaviour, but unlike noatime it still retains atime updates. IOWs there's a pretty good chance that noatime has little measurable impact on your application's performance, but understanding and benchmarking anything other than your application won't tell you this. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs