From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p3RGqpEa223134 for ; Wed, 27 Apr 2011 11:52:51 -0500 Subject: Re: [PATCH 4/4] xfs: reduce the number of pagb_lock roundtrips in xfs_alloc_clear_busy From: Alex Elder In-Reply-To: <20110424190657.249817918@bombadil.infradead.org> References: <20110424190613.404786382@bombadil.infradead.org> <20110424190657.249817918@bombadil.infradead.org> Date: Wed, 27 Apr 2011 11:56:21 -0500 Message-ID: <1303923381.2056.58.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: Christoph Hellwig Cc: xfs@oss.sgi.com On Sun, 2011-04-24 at 15:06 -0400, Christoph Hellwig wrote: > Instead of finding the per-ag and then taking and releasing the pagb_lock > for every single busy extent completed sort the list of busy extents and > only switch betweens AGs where nessecary. This becomes especially important > with the online discard support which will hit this lock more often. > > Signed-off-by: Christoph Hellwig I said this looked good before, but since you haven't indicated that here yet, I'll make one more comment. Both places that call (the new) xfs_alloc_busy_clear() precede the call with a call to xfs_alloc_busy_sort(). Considering that, and the fact that xfs_alloc_busy_clear() depends on the list being sorted for correct (or at least efficient) operation, I think you should just embed the list_sort() call in xfs_alloc_busy_clear(). There would then be no real need to define the xfs_alloc_busy_sort() helper (just call list_sort() directly), and you can move the definition of xfs_busy_extent_ag_cmp() up in the file and give it private scope. Perhaps you have other plans that make the model you have here more appropriate though. Let me know if you intend to re-submit, otherwise I'll just take this version. Either way, this looks good to me. I have been testing with these patches. I'll wait another day to give others a chance to review, but I'll plan to incorporate this tomorrow. Reviewed-by: Alex Elder _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs