From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751321Ab1DUEfJ (ORCPT <rfc822;w@1wt.eu>);
	Thu, 21 Apr 2011 00:35:09 -0400
Received: from bombadil.infradead.org ([18.85.46.34]:45839 "EHLO
	bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750928Ab1DUEfH (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Thu, 21 Apr 2011 00:35:07 -0400
Date: Thu, 21 Apr 2011 00:34:50 -0400
From: Christoph Hellwig <hch@infradead.org>
To: Wu Fengguang <fengguang.wu@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, Jan Kara <jack@suse.cz>,
        Mel Gorman <mel@linux.vnet.ibm.com>,
        Dave Chinner <david@fromorbit.com>,
        Trond Myklebust <Trond.Myklebust@netapp.com>,
        Itaru Kitayama <kitayama@cl.bb4u.ne.jp>,
        Minchan Kim <minchan.kim@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>, linux-fsdevel@vger.kernel.org,
        Linux Memory Management List <linux-mm@kvack.org>
Subject: Re: [PATCH 0/6] writeback: moving expire targets for
 background/kupdate works
Message-ID: <20110421043449.GA22423@infradead.org>
References: <20110419030003.108796967@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20110419030003.108796967@intel.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
X-SRS-Rewrite: SMTP reverse-path rewritten from <hch@infradead.org> by bombadil.infradead.org
	See http://www.infradead.org/rpr.html
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Wu,

if you're queueing up writeback changes can you look into splitting
inode_wb_list_lock as it was done in earlier versions of the inode
scalability patches?  Especially if we don't get the I/O less
balance_dirty_pages in ASAP it'll at least allows us to scale the
busy waiting for the list manipulationes to one CPU per BDI.