From owner-freebsd-current@FreeBSD.ORG Tue May 23 14:16:50 2006 Return-Path: X-Original-To: current@freebsd.org Delivered-To: freebsd-current@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5C24216A4FD for ; Tue, 23 May 2006 14:16:50 +0000 (UTC) (envelope-from keramida@ceid.upatras.gr) Received: from igloo.linux.gr (igloo.linux.gr [62.1.205.36]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8EA4E43D5D for ; Tue, 23 May 2006 14:16:43 +0000 (GMT) (envelope-from keramida@ceid.upatras.gr) Received: from gothmog.pc (host5.bedc.ondsl.gr [62.103.39.229]) (authenticated bits=128) by igloo.linux.gr (8.13.6/8.13.6/Debian-1) with ESMTP id k4NEFm64014336 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Tue, 23 May 2006 17:16:15 +0300 Received: from gothmog.pc (gothmog [127.0.0.1]) by gothmog.pc (8.13.6/8.13.6) with ESMTP id k4NEHvQS003262; Tue, 23 May 2006 17:17:57 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Received: (from giorgos@localhost) by gothmog.pc (8.13.6/8.13.6/Submit) id k4NEHvG0003261; Tue, 23 May 2006 17:17:57 +0300 (EEST) (envelope-from keramida@ceid.upatras.gr) Date: Tue, 23 May 2006 17:17:57 +0300 From: Giorgos Keramidas To: mlfbsd Message-ID: <20060523141757.GA2966@gothmog.pc> References: <20060522211223.GA3621@xor.obsecurity.org> <20060522231437.GC1446@odin.ac.hmc.edu> <20060523133037.GA2908@gothmog.pc> <20060523143013.GA11472@ci0.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060523143013.GA11472@ci0.org> X-Hellug-MailScanner: Found to be clean X-Hellug-MailScanner-SpamCheck: not spam, SpamAssassin (score=-3.405, required 5, autolearn=not spam, ALL_TRUSTED -1.80, AWL 0.79, BAYES_00 -2.60, DNS_FROM_RFC_ABUSE 0.20) X-Hellug-MailScanner-From: keramida@ceid.upatras.gr X-Spam-Status: No Cc: current@freebsd.org, Kris Kennaway Subject: Re: md /tmp and async mounts X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 May 2006 14:16:51 -0000 On 2006-05-23 16:30, mlfbsd wrote: >On Tue, May 23, 2006 at 04:30:37PM +0300, Giorgos Keramidas wrote: >>On 2006-05-22 16:14, Brooks Davis wrote: >>>On Mon, May 22, 2006 at 05:12:24PM -0400, Kris Kennaway wrote: >>>> I noticed that with tmpmfs in rc.conf, the md is not being >>>> mounted with -o async; this is an enormous performance >>>> boost, so is there a reason it is not used, or just that it >>>> was overlooked? >>> >>> Just overlooked as far as I know. We correctly switched to >>> not mounting with softupdates, but should probably switch to >>> -o async. >> >> Right. The only reasons why the current tmpmfs_flags doesn't >> include the `-o async' option too are: >> >> a) It didn't back when it was all hardcoded in the script >> >> b) I didn't think about adding it by default when revision >> 1.230 of src/etc/defaults/rc.conf was committed by me >> >> If it does improve things, we should probably make the change :) > > The sys/dev/md/md.c rev 1.115 commit log says async used to be > the default, but was switched off because it was causing > deadlocks. Did this get fixed since ? I am not sure. If a deadlock *does* exist though, then it's not an improvement and we should definitely keep the default to its current state until the bug is fixed.