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 (Postfix) with ESMTP id 064187F58 for ; Wed, 4 Sep 2013 10:09:01 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id E89C28F8040 for ; Wed, 4 Sep 2013 08:08:57 -0700 (PDT) Received: from mx2.suse.de (cantor2.suse.de [195.135.220.15]) by cuda.sgi.com with ESMTP id Gos8zwjsK0aYSEWs for ; Wed, 04 Sep 2013 08:08:57 -0700 (PDT) Date: Wed, 4 Sep 2013 17:08:54 +0200 From: Jan Kara Subject: Re: [PATCH v3 0/5] Rework mtime and ctime updates on mmaped writes Message-ID: <20130904150854.GF3996@quack.suse.cz> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Andy Lutomirski Cc: Theodore Ts'o , Dave Hansen , linux-kernel@vger.kernel.org, xfs@oss.sgi.com, Christoph Hellwig , Jan Kara , linux-ext4@vger.kernel.org, Tim Chen On Thu 22-08-13 17:03:16, Andy Lutomirski wrote: > Writes via mmap currently update mtime and ctime in ->page_mkwrite. > This hurts both throughput and latency. In workloads that dirty a > large number of mmapped pages, ->page_mkwrite can be hot and > file_update_time is slow and scales poorly. Updating timestamps can > also sleep, which hurts latency for real-time workloads. It would help to make your case if you posted the latency comparison before & after the patchset in this introductory email. We can then see how significant is the reduction of latency... Honza -- Jan Kara SUSE Labs, CR _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs