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 pAMMZrqK175875 for ; Tue, 22 Nov 2011 16:35:53 -0600 Received: from out2.smtp.messagingengine.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id B3E8516DC8A0 for ; Tue, 22 Nov 2011 14:35:52 -0800 (PST) Received: from out2.smtp.messagingengine.com (out2.smtp.messagingengine.com [66.111.4.26]) by cuda.sgi.com with ESMTP id SHcj616YI8fnLAfb for ; Tue, 22 Nov 2011 14:35:52 -0800 (PST) Received: from compute4.internal (compute4.nyi.mail.srv.osa [10.202.2.44]) by gateway1.nyi.mail.srv.osa (Postfix) with ESMTP id ED9C620C10 for ; Tue, 22 Nov 2011 17:35:51 -0500 (EST) Date: Tue, 22 Nov 2011 13:35:44 -0800 From: Greg KH Subject: Re: [PATCH 4/9] [PATCH 4/9] xfs: dont serialise direct IO reads on page cache Message-ID: <20111122213544.GB29127@kroah.com> References: <20111119181336.964593075@bombadil.infradead.org> <20111119181544.111984285@bombadil.infradead.org> <20111122213425.GA29127@kroah.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111122213425.GA29127@kroah.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: Alex Elder , Dave Chinner , stable@vger.kernel.org, xfs@oss.sgi.com On Tue, Nov 22, 2011 at 01:34:25PM -0800, Greg KH wrote: > On Sat, Nov 19, 2011 at 01:13:40PM -0500, Christoph Hellwig wrote: > > There is no need to grab the i_mutex of the IO lock in exclusive > > mode if we don't need to invalidate the page cache. Taking these > > locks on every direct IO effective serialises them as taking the IO > > lock in exclusive mode has to wait for all shared holders to drop > > the lock. That only happens when IO is complete, so effective it > > prevents dispatch of concurrent direct IO reads to the same inode. > > > > Fix this by taking the IO lock shared to check the page cache state, > > and only then drop it and take the IO lock exclusively if there is > > work to be done. Hence for the normal direct IO case, no exclusive > > locking will occur. > > > > Signed-off-by: Dave Chinner > > Tested-by: Joern Engel > > Reviewed-by: Christoph Hellwig > > Signed-off-by: Alex Elder > > What is the git commit id that matches this patch in Linus's tree? Nevermind, I found it, 0c38a2512df272b14ef4238b476a2e4f70da1479, right? Next time, please include the git commit id of the patch in Linus's tree so I don't have to dig it out like I did for this series. thanks, greg k-h _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs