From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with SMTP id p2I3vDl0011696 for ; Thu, 17 Mar 2011 22:57:18 -0500 Received: from ipmail04.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id DC9CB35F41E for ; Thu, 17 Mar 2011 21:00:09 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id fISve0W2euvQuBkO for ; Thu, 17 Mar 2011 21:00:09 -0700 (PDT) Date: Fri, 18 Mar 2011 15:00:06 +1100 From: Dave Chinner Subject: Re: [PATCH 4/6] xfs: introduce background inode reclaim work Message-ID: <20110318040006.GF30195@dastard> References: <1299715529-11026-1-git-send-email-david@fromorbit.com> <1299715529-11026-5-git-send-email-david@fromorbit.com> <20110310174054.GD19609@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110310174054.GD19609@infradead.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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Thu, Mar 10, 2011 at 12:40:54PM -0500, Christoph Hellwig wrote: > Why do we still keep the inode reclaim in the syncer work? If we > already have this one doing it I don't think we need it there as well. Ok. Removed. > > /* > > + * Queue a new inode reclaim pass if there isn't one already in progress. > > + * Wait for completion of the flush if necessary. > > No, it doesn't wait ever. Removed. > > + */ > > +static void > > +xfs_syncd_queue_reclaim( > > + struct xfs_mount *mp) > > +{ > > + queue_delayed_work(xfs_syncd_wq, &mp->m_reclaim_work, > > + xfs_syncd_centisecs / 5 * msecs_to_jiffies(10)); > > What explanation is there for the magic 5? E.g. why do we neeed to run > it exactly 5 times as often as the normal sync work? It doesn't have to be exactly 5x more frequent, just that it needs to run quite a bit more often than the normal sync work. tens times more often seems like overkill and a lot of overhead given the scan reclaim does, while two times more often isn't sufficient to avoid significant build up of dirty reclaimable inodes that need to be written before they can be reclaimed.. > Should it have it's > own tunable? Perhaps. I'm not convinced it is necessary, though. > And isn't ever 6 seconds by default a little often on > systems trying to saver power, especiall if there aren't any inodes to > reclaim? Should we trigger starting this work off having reclaimable > inodes tagged in the radix tree? Yes, probably should. I'll see if I can do that easily. > > + /* first unpin all the dirty and stale inodes. */ > > + xfs_log_force(mp, XFS_LOG_SYNC); > > So we force out the log every 6 seconds. That's a lot more often than > most other filesystem and might have adverse performance impact. I'll remove that and leave it for the sync inode reclaim to force out the log... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs