From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p7M6hnqj036394 for ; Mon, 22 Aug 2011 01:43:50 -0500 Received: from ipmail07.adl2.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id C617A1388818 for ; Sun, 21 Aug 2011 23:46:21 -0700 (PDT) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id OYpKTIr1TddWjhmQ for ; Sun, 21 Aug 2011 23:46:21 -0700 (PDT) Date: Mon, 22 Aug 2011 16:43:45 +1000 From: Dave Chinner Subject: Re: [PATCH 3/5] xfs: reduce ioend latency Message-ID: <20110822064345.GM3162@dastard> References: <20110814222412.359079843@bombadil.infradead.org> <20110814222518.001177781@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110814222518.001177781@bombadil.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 Sun, Aug 14, 2011 at 06:24:15PM -0400, Christoph Hellwig wrote: > There is no reason to queue up ioends for processing in user context > unless we actually need it. Just complete ioends that do not convert > unwritten extents or need a size update from the end_io context. > > Signed-off-by: Christoph Hellwig > > Index: xfs/fs/xfs/xfs_aops.c > =================================================================== > --- xfs.orig/fs/xfs/xfs_aops.c 2011-08-13 10:57:57.559366326 -0700 > +++ xfs/fs/xfs/xfs_aops.c 2011-08-13 10:57:57.979364052 -0700 > @@ -150,6 +150,15 @@ xfs_ioend_new_eof( > } > > /* > + * Fast and loose check if this write could update the on-disk inode size. > + */ > +static inline bool xfs_ioend_is_append(struct xfs_ioend *ioend) > +{ > + return ioend->io_offset + ioend->io_size > > + XFS_I(ioend->io_inode)->i_d.di_size; > +} > + > +/* > * Update on-disk file size now that data has been written to disk. The > * current in-memory file size is i_size. If a write is beyond eof i_new_size > * will be the intended file size until i_size is updated. If this write does > @@ -186,6 +195,9 @@ xfs_setfilesize( > > /* > * Schedule IO completion handling on the final put of an ioend. > + * > + * If there is no work to do we might as well call it a day and free the > + * ioend right now. > */ > STATIC void > xfs_finish_ioend( > @@ -194,8 +206,10 @@ xfs_finish_ioend( > if (atomic_dec_and_test(&ioend->io_remaining)) { > if (ioend->io_type == IO_UNWRITTEN) > queue_work(xfsconvertd_workqueue, &ioend->io_work); > - else > + else if (xfs_ioend_is_append(ioend)) > queue_work(xfsdatad_workqueue, &ioend->io_work); > + else > + xfs_destroy_ioend(ioend); > } > } That's similar to a check I added in a previous patch series to avoid taking the ILOCK in IO completion if it wasn't necessary. THis just checks earlier to avoid the workqueue switch, so it definitely better than what I did. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs