Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262266AbUCJXgt (ORCPT ); Wed, 10 Mar 2004 18:36:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262558AbUCJXgt (ORCPT ); Wed, 10 Mar 2004 18:36:49 -0500 Received: from outgoingmail.adic.com ([63.81.117.28]:24668 "EHLO localhost.localdomain") by vger.kernel.org with ESMTP id S262266AbUCJXgs (ORCPT ); Wed, 10 Mar 2004 18:36:48 -0500 Message-ID: <404FA575.1090907@xfs.org> Date: Wed, 10 Mar 2004 17:32:05 -0600 From: Steve Lord User-Agent: Mozilla Thunderbird 0.5 (X11/20040208) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Nathan Scott CC: Jens Axboe , Linux Kernel , kenneth.w.chen@intel.com, Andrew Morton , thornber@redhat.com, linux-xfs@oss.sgi.com Subject: Re: [PATCH] backing dev unplugging References: <20040310124507.GU4949@suse.de> <20040310222247.GA713@frodo> In-Reply-To: <20040310222247.GA713@frodo> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1395 Lines: 32 Nathan Scott wrote: > > For this second one, we probably just want to ditch the flush_cnt > there (this change is doing blk_run_address_space on every 32nd > buffer target, and not the intervening ones). We will be doing a > bunch more blk_run_address_space calls than we probably need to, > not sure if thats going to become an issue or not, let me prod > some of the other XFS folks for more insight there... > > thanks. > The concept there was that we were just pushing things down into the elevator in a batch, then unplugging it afterwards. The do it every 32 I/O's was added to avoid some request starvation issues - which are probably historical now. I was lazy and did not look at the context on the code, but there are two paths in here. One is unmount flushing all the entries for a specific filesystem, the other is background flushing. I think the background flush activity can live without the blk_run_address_space call being there at all. If we need to grab the lock on the metadata later we will make the call then. The unmount case needs to call it, but since that specifies a specific target, it can just make one call. Steve - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/