From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756189AbZDPWqH (ORCPT ); Thu, 16 Apr 2009 18:46:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754959AbZDPWpy (ORCPT ); Thu, 16 Apr 2009 18:45:54 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:55084 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754619AbZDPWpx (ORCPT ); Thu, 16 Apr 2009 18:45:53 -0400 Date: Thu, 16 Apr 2009 15:29:37 -0700 From: Andrew Morton To: Andrea Righi Cc: menage@google.com, balbir@linux.vnet.ibm.com, guijianfeng@cn.fujitsu.com, kamezawa.hiroyu@jp.fujitsu.com, agk@sourceware.org, axboe@kernel.dk, baramsori72@gmail.com, chlunde@ping.uio.no, dave@linux.vnet.ibm.com, dpshah@google.com, eric.rannaud@gmail.com, fernando@oss.ntt.co.jp, taka@valinux.co.jp, lizf@cn.fujitsu.com, matt@bluehost.com, dradford@bluehost.com, ngupta@google.com, randy.dunlap@oracle.com, roberto@unbit.it, ryov@valinux.co.jp, s-uchida@ap.jp.nec.com, subrata@linux.vnet.ibm.com, yoshikawa.takuya@oss.ntt.co.jp, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/9] bio-cgroup controller Message-Id: <20090416152937.b2188370.akpm@linux-foundation.org> In-Reply-To: <1239740480-28125-4-git-send-email-righi.andrea@gmail.com> References: <1239740480-28125-1-git-send-email-righi.andrea@gmail.com> <1239740480-28125-4-git-send-email-righi.andrea@gmail.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 14 Apr 2009 22:21:14 +0200 Andrea Righi wrote: > Subject: [PATCH 3/9] bio-cgroup controller Sorry, but I have to register extreme distress at the name of this. The term "bio" is well-established in the kernel and here we have a new definition for the same term: "block I/O". "bio" was a fine term for you to have chosen from the user's perspective, but from the kernel developer perspective it is quite horrid. The patch adds a vast number of new symbols all into the existing "bio_" namespace, many of which aren't related to `struct bio' at all. At least, I think that's what's happening. Perhaps the controller really _is_ designed to track `struct bio'? If so, that's an odd thing to tell userspace about. > The controller bio-cgroup is used by io-throttle to track writeback IO > and for properly apply throttling. Presumably it tracks all forms of block-based I/O and not just delayed writeback.