From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 30 Apr 2008 03:58:12 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m3UAvnt3032142 for ; Wed, 30 Apr 2008 03:57:52 -0700 Date: Wed, 30 Apr 2008 06:58:32 -0400 From: Christoph Hellwig Subject: Re: [PATCH] Remove l_flushsema Message-ID: <20080430105832.GA20442@infradead.org> References: <20080430090502.GH14976@parisc-linux.org> <20080430104125.GM108924158@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080430104125.GM108924158@sgi.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: David Chinner Cc: Matthew Wilcox , xfs@oss.sgi.com, linux-fsdevel@vger.kernel.org On Wed, Apr 30, 2008 at 08:41:25PM +1000, David Chinner wrote: > The only thing that I'm concerned about here is that this will > substantially increase the time the l_icloglock is held. This is > a severely contended lock on large cpu count machines and putting > the wakeup inside this lock will increase the hold time. > > I guess I can address this by adding a new lock for the waitqueue > in a separate patch set. waitqueues are loked internally and don't need synchronization. With a little bit of re-arranging the code the wake_up could probably be moved out of the critical section.