From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id oBM2K6m2145538 for ; Tue, 21 Dec 2010 20:20:06 -0600 Subject: Re: [PATCH 20/34] xfs: remove all the inodes on a buffer from the AIL in bulk From: Alex Elder In-Reply-To: <1292916570-25015-21-git-send-email-david@fromorbit.com> References: <1292916570-25015-1-git-send-email-david@fromorbit.com> <1292916570-25015-21-git-send-email-david@fromorbit.com> Date: Tue, 21 Dec 2010 20:20:46 -0600 Message-ID: <1292984446.2408.358.camel@doink> Mime-Version: 1.0 Reply-To: aelder@sgi.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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com On Tue, 2010-12-21 at 18:29 +1100, Dave Chinner wrote: > From: Dave Chinner > > When inode buffer IO completes, usually all of the inodes are removed from the > AIL. This involves processing them one at a time and taking the AIL lock once > for every inode. When all CPUs are processing inode IO completions, this causes > excessive amount sof contention on the AIL lock. > > Instead, change the way we process inode IO completion in the buffer > IO done callback. Allow the inode IO done callback to walk the list > of IO done callbacks and pull all the inodes off the buffer in one > go and then process them as a batch. > > Once all the inodes for removal are collected, take the AIL lock > once and do a bulk removal operation to minimise traffic on the AIL > lock. > > Signed-off-by: Dave Chinner > Reviewed-by: Christoph Hellwig One question, below. -Alex . . . > @@ -861,28 +910,37 @@ xfs_iflush_done( > * the lock since it's cheaper, and then we recheck while > * holding the lock before removing the inode from the AIL. > */ > - if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn) { > + if (need_ail) { > + struct xfs_log_item *log_items[need_ail]; What's the worst-case value of need_ail we might see here? _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs