From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 09 Apr 2008 22:48:47 -0700 (PDT) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id m3A5mb6U008706 for ; Wed, 9 Apr 2008 22:48:39 -0700 Date: Thu, 10 Apr 2008 15:49:13 +1000 From: David Chinner Subject: Re: [patch] remove unnecessary periodic superblock logging. Message-ID: <20080410054913.GL108924158@sgi.com> References: <20080410042001.GF108924158@sgi.com> <47FDA5BA.3080401@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <47FDA5BA.3080401@sgi.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Timothy Shimmin Cc: David Chinner , Barry Naujok , xfs-dev , xfs-oss On Thu, Apr 10, 2008 at 03:29:30PM +1000, Timothy Shimmin wrote: > Barry Naujok wrote: > >On Thu, 10 Apr 2008 14:20:01 +1000, David Chinner wrote: > > > >>Remove periodic logging of in-core superblock counters. > >> > >>xfssyncd triggers the logging of superblock counters every > >>30s if the filesystem is made with lazy-count=1. This will > >>prevent disks from idling and spinning down as there will > >>be a log write every 30s. With the way counter recovery > >>works for lazy-count=1, this code is unnecessary and provides > >>no real benefit, so just remove it. > > > >I'm happy with this (xfs_initialize_perag_data() does the > >global counter recovery during mount). > > > > So we only do the sb count logging at unmount type times... > xfs_attr_quiesce() and xfs_unmountfs(), > when no log recovery will happen. > Hmmm...so why do we have to log it out at these times? > I'm forgetting how this works. xfs_log_sbcount() sync's the incore counters to the superblock buffer transactionally. Not strictly necessary, but for consistency with other superblock updates..... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group