From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752772Ab3GHR4Q (ORCPT ); Mon, 8 Jul 2013 13:56:16 -0400 Received: from mail-qe0-f43.google.com ([209.85.128.43]:33803 "EHLO mail-qe0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751648Ab3GHR4O (ORCPT ); Mon, 8 Jul 2013 13:56:14 -0400 Date: Mon, 8 Jul 2013 10:56:07 -0700 From: Tejun Heo To: Vivek Goyal Cc: Konstantin Khlebnikov , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , cgroups@vger.kernel.org, Andrew Morton , Sha Zhengju , devel@openvz.org, Jens Axboe Subject: Re: [PATCH RFC] fsio: filesystem io accounting cgroup Message-ID: <20130708175607.GB18600@mtj.dyndns.org> References: <20130708100046.14417.12932.stgit@zurg> <20130708170047.GA18600@mtj.dyndns.org> <20130708175201.GB9094@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130708175201.GB9094@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Vivek. On Mon, Jul 08, 2013 at 01:52:01PM -0400, Vivek Goyal wrote: > > Again, a problem to be fixed in the stack rather than patching up from > > up above. The right thing to do is to propagate pressure through bdi > > properly and let whatever is backing the bdi generate appropriate > > amount of pressure, be that disk or network. > > Ok, so use network controller for controlling IO rate on NFS? I had > tried it once and it did not work. I think it had problems related > to losing the context info as IO propagated through the stack. So > we will have to fix that too. But that's a similar problem we have with blkcg anyway - losing the dirtier information by the time writeback comes down through bdi. It might not be exactly the same and might need some impedance matching on the network side but I don't see any fundamental differences. Thanks. -- tejun