From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: SSD slowdown with 3.3.X? Date: Mon, 23 Apr 2012 08:44:44 -0400 Message-ID: <4F954EBC.8060508@teksavvy.com> References: <4F8F7533.6020300@gmail.com> <4F8F82EC.1060708@teksavvy.com> <4F90C4CF.1010000@gmail.com> <4F921E18.6000301@teksavvy.com> <4F921ECF.2080303@teksavvy.com> <4F922F43.4050809@hardwarefreak.com> <4F92FCA9.8010502@hardwarefreak.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ironport-out.teksavvy.com ([206.248.143.162]:14766 "EHLO ironport-out.teksavvy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752827Ab2DWMoo (ORCPT ); Mon, 23 Apr 2012 08:44:44 -0400 In-Reply-To: <4F92FCA9.8010502@hardwarefreak.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: stan@hardwarefreak.com Cc: cwillu , Joe Ceklosky , "linux-ide@vger.kernel.org >> IDE/ATA development list" On 12-04-21 02:30 PM, Stan Hoeppner wrote: > On 4/21/2012 6:45 AM, cwillu wrote: >>> Probably not relevant in this case but maybe worth mentioning to get the >>> word out: >>> >>> "As of kernel 3.2.12, the default i/o scheduler, CFQ, will defeat much >>> of the parallelization in XFS." >>> >>> http://www.xfs.org/index.php/XFS_FAQ >> >> Not that it's terribly relevant to btrfs, but do you have a better >> citation for that than a very recent one-line wiki change that only >> cites the user's own anecdote? > > Apologies for the rather weak citation. It was simply easier to quote > that wiki entry. > > How about something directly from Dave's fingers: > http://www.spinics.net/lists/xfs/msg10824.html > > The many issues with CFQ+XFS didn't start with 3.2.12, but long before that. Thanks for the link. That's handy to know. The problems there are for XFS+RAID vs. CFQ, not XFS by itself. Enterprise servers will normally have RAID under XFS, but not all smaller systems. Cheers