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 ESMTP id oBKBl3aN117306 for ; Mon, 20 Dec 2010 05:47:03 -0600 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 0253D20E0E1 for ; Mon, 20 Dec 2010 03:49:00 -0800 (PST) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id bIGFyKVd4iV18PGS for ; Mon, 20 Dec 2010 03:49:00 -0800 (PST) Date: Mon, 20 Dec 2010 06:49:00 -0500 From: Christoph Hellwig Subject: Re: [PATCH 10/12] xfs: introduce new locks for the log grant ticket wait queues Message-ID: <20101220114900.GF12806@infradead.org> References: <1292215483-18224-1-git-send-email-david@fromorbit.com> <1292215483-18224-11-git-send-email-david@fromorbit.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1292215483-18224-11-git-send-email-david@fromorbit.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 Mon, Dec 13, 2010 at 03:44:41PM +1100, Dave Chinner wrote: > From: Dave Chinner > > The log grant ticket wait queues are currently protected by the log > grant lock. However, the queues are functionally independent from > each other, and operations on them only require serialisation > against other queue operations now that all of the other log > variables they use are atomic values. > > Hence, we can make them independent of the grant lock by introducing > new locks just to protect the lists operations. because the lists > are independent, we can use a lock per list and ensure that reserve > and write head queuing do not contend. > > To ensure forced shutdowns work correctly in conjunction with the > new fast paths, ensure that we check whether the log has been shut > down in the grant functions once we hold the relevant spin locks but > before we go to sleep. This is needed to co-ordinate correctly with > the wakeups that are issued on the ticket queues so we don't leave > any processes sleeping on the queues during a shutdown. > > Signed-off-by: Dave Chinner Looks good, Reviewed-by: Christoph Hellwig _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs