From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: writeback fixes for 3.2-rc5 Date: Tue, 13 Dec 2011 19:24:16 +0800 Message-ID: <20111213112416.GA5577@localhost> References: <1323066138-10428-1-git-send-email-fengguang.wu@intel.com> <20111212102947.GA6731@localhost> <20111212204634.GB5214@quack.suse.cz> <20111213014456.GA9963@localhost> <20111213105711.GB11747@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-fsdevel@vger.kernel.org" To: Jan Kara Return-path: Received: from mga14.intel.com ([143.182.124.37]:38774 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751521Ab1LMLeU (ORCPT ); Tue, 13 Dec 2011 06:34:20 -0500 Content-Disposition: inline In-Reply-To: <20111213105711.GB11747@quack.suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Tue, Dec 13, 2011 at 06:57:11PM +0800, Jan Kara wrote: > On Tue 13-12-11 09:44:56, Wu Fengguang wrote: > > On Tue, Dec 13, 2011 at 04:46:34AM +0800, Jan Kara wrote: > > > Hi Fengguang, > > > > > > On Mon 12-12-11 18:29:48, Wu Fengguang wrote: > > > > May I ask if you see any problems pushing these patches to Linus? > > > Sorry, this somehow escaped my attention. Patches 1, 2, 3, and 5 are > > > fine. I'm not sure about patch 4 - I'm not against it but e.g. on > > > single-cpu machine, bdi_stat_error() is 1 so there the patch won't help > > > > As the comment said, actually 1 is enough to let the tasks go through. > > It may sound terrible to write 1 page at a time, however it's already > > much better than being blocked there forever. The user experience is > > totally different according to my tests, because most tasks are not IO > > intensive at all, they are blocked simply on writing some small file. > > > > > much. Enconding fixed constant like you had in the first version of the > > > patch doesn't look nice either. But I don't have a better solution... > > > > My typical need on the global exceeded case is "please at least let me > > ssh in and kill some task or raise the dirty limit to break out of the > > error condition". IMHO the patch is good enough for that need. > Yes, I understand it's better than nothing. That's why I think it's an > acceptable solution at least for now. I just don't feel completely > satisfied with it :). So please go ahead and merge the fixes with Linus. OK, thanks! :) Fengguang