From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755521Ab2DNLyB (ORCPT ); Sat, 14 Apr 2012 07:54:01 -0400 Received: from casper.infradead.org ([85.118.1.10]:59567 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754952Ab2DNLx7 convert rfc822-to-8bit (ORCPT ); Sat, 14 Apr 2012 07:53:59 -0400 Message-ID: <1334404423.2528.75.camel@twins> Subject: Re: [Lsf] [RFC] writeback and cgroup From: Peter Zijlstra To: Tejun Heo Cc: Vivek Goyal , ctalbott@google.com, rni@google.com, andrea@betterlinux.com, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org, lsf@lists.linux-foundation.org, linux-mm@kvack.org, jmoyer@redhat.com, lizefan@huawei.com, linux-fsdevel@vger.kernel.org, cgroups@vger.kernel.org Date: Sat, 14 Apr 2012 13:53:43 +0200 In-Reply-To: <20120404184909.GB29686@dhcp-172-17-108-109.mtv.corp.google.com> References: <20120403183655.GA23106@dhcp-172-17-108-109.mtv.corp.google.com> <20120404145134.GC12676@redhat.com> <20120404184909.GB29686@dhcp-172-17-108-109.mtv.corp.google.com> Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Mailer: Evolution 3.2.2- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2012-04-04 at 11:49 -0700, Tejun Heo wrote: > > - How to handle NFS. > > As said above, maybe through network based bdi pressure propagation, > Maybe some other special case mechanism. Unsure but I don't think > this concern should dictate the whole design. NFS has a custom bdi implementation and implements congestion control based on the number of outstanding writeback pages. See fs/nfs/write.c:nfs_{set,end}_page_writeback All !block based filesystems have their own BDI implementation, I'm not sure on the congestion implementation of anything other than NFS though.