From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 760C27F51 for ; Sun, 23 Feb 2014 16:10:51 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id E2A22AC003 for ; Sun, 23 Feb 2014 14:10:47 -0800 (PST) Received: from greer.hardwarefreak.com (mo-65-41-216-221.sta.embarqhsd.net [65.41.216.221]) by cuda.sgi.com with ESMTP id keFJ7EIaGaj91H05 for ; Sun, 23 Feb 2014 14:10:46 -0800 (PST) Message-ID: <530A71E3.9060107@hardwarefreak.com> Date: Sun, 23 Feb 2014 16:10:43 -0600 From: Stan Hoeppner MIME-Version: 1.0 Subject: Re: gentoo linux, kernel 3.10.31 mount options bug? References: <9963a76fbd006355c9ffd79f341c9971@zbfmail.de> In-Reply-To: <9963a76fbd006355c9ffd79f341c9971@zbfmail.de> Reply-To: stan@hardwarefreak.com 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: weber@zbfmail.de, Xfs On 2/23/2014 3:37 AM, Marko Weber|8000 wrote: ... > linux /bzImage-3.10.31 root=/dev/md2 elevator=cfq clocksource=hpet ^^^^^^^^^^^^ cfq tends to defeat much of the parallelism in XFS, decreasing throughput substantially. This is documented in the XFS FAQ and has been discussed here many times in the past. It has been recommended for a few years now that XFS not be used with the cfq elevator. Use deadline with md arrays on plain HBAs and noop on SSDs or any device with [F|B]BWC, i.e. RAID HBA or SAN controller. If you're using cfq to allow shaping of per process IO with control groups, simply using cfq alone may slow down XFS throughput to the point that you don't need to bother with control group optimizations. -- Stan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs