From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCHSET] cgroup: cftype based file interface, take #2 Date: Fri, 30 Mar 2012 08:42:46 -0700 Message-ID: <20120330154246.GE28934@google.com> References: <1332368265-21586-1-git-send-email-tj@kernel.org> <4F75AA1F.9020007@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=SHio5Ga87aBXCmiQz0CUTjK0Wz+iPp2jEriTrYH9xeY=; b=EMIyo7UlZjuilSaNmyU8B2UJf1SohzGQUeONsCd9WkxjEftV8ifM+ZbsHW1gxzylNC o5N7EmsEeqUPq0YQLMsl2Ng5HpR1+pTcm25GzJxiJAqrYoDLcKKCQRoXnlLpFcViFmhh eJ+lbogSSXEFr94aTY1dOcZi/B8YZSy8Jl6AA6iZtJywq//OIySDX/A4ZngH6xtOIFjj pTKrwnkmmTKRAFvPy7elwVS1qnIGHwenlUF3Id5VEC3+CAN7jxr/q5hgpV1DUYryx5/U swcUVEJ+VJ5vv7kt58dyLGIw7VEPSbZgmz7KDpG84K1wj7iiN165zwJfKoyplMBp4L/H iUMg== Content-Disposition: inline In-Reply-To: <4F75AA1F.9020007-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Li Zefan Cc: ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, fweisbec-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Hey, Li. On Fri, Mar 30, 2012 at 08:42:07PM +0800, Li Zefan wrote: > > This patch replaces cgroup file interface with cftype based one which > > allows dynamic additions and removals of cftype arrays whether the > > target subsystem is attached or not. This can be used to make subsys > > rebinding via remount work properly but I intentionally avoided doing > > that at the moment. > > What's the problem with remount? Subsys can't be changed if any non-root cgroup exists. > and is it important enough that it should be fixed even the feature > is marked as deprecated? I'm not sure. We *might* need it during multi-mount -> single-mount transition depending on how that's implemented, so the "at the moment" qualifier. It probably won't be fixed but I'm not fully sure. > > This makes cgroup population simpler for controllers and will be used > > to allow controllers to be more dynamic. e.g. blkio subsys has > > sub-policies which may come and go while blkio subsys is attached and > > it currently uses fixed set of files which stays blank if not in use. > > Dynamic cgroup files was mentioned before. The scenario in mind was blkio > control files can be added/removed automatically as devices come and ago. > > So this time blkio subsystem is really going to be made more dynamic > soon? Patchset already posted. http://thread.gmane.org/gmane.linux.kernel.cgroups/1376 Thanks. -- tejun From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932832Ab2C3Pm6 (ORCPT ); Fri, 30 Mar 2012 11:42:58 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:59083 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753470Ab2C3Pmu (ORCPT ); Fri, 30 Mar 2012 11:42:50 -0400 Date: Fri, 30 Mar 2012 08:42:46 -0700 From: Tejun Heo To: Li Zefan Cc: glommer@parallels.com, lizf@cn.fujitsu.com, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, rni@google.com, ctalbott@google.com Subject: Re: [PATCHSET] cgroup: cftype based file interface, take #2 Message-ID: <20120330154246.GE28934@google.com> References: <1332368265-21586-1-git-send-email-tj@kernel.org> <4F75AA1F.9020007@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4F75AA1F.9020007@huawei.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hey, Li. On Fri, Mar 30, 2012 at 08:42:07PM +0800, Li Zefan wrote: > > This patch replaces cgroup file interface with cftype based one which > > allows dynamic additions and removals of cftype arrays whether the > > target subsystem is attached or not. This can be used to make subsys > > rebinding via remount work properly but I intentionally avoided doing > > that at the moment. > > What's the problem with remount? Subsys can't be changed if any non-root cgroup exists. > and is it important enough that it should be fixed even the feature > is marked as deprecated? I'm not sure. We *might* need it during multi-mount -> single-mount transition depending on how that's implemented, so the "at the moment" qualifier. It probably won't be fixed but I'm not fully sure. > > This makes cgroup population simpler for controllers and will be used > > to allow controllers to be more dynamic. e.g. blkio subsys has > > sub-policies which may come and go while blkio subsys is attached and > > it currently uses fixed set of files which stays blank if not in use. > > Dynamic cgroup files was mentioned before. The scenario in mind was blkio > control files can be added/removed automatically as devices come and ago. > > So this time blkio subsystem is really going to be made more dynamic > soon? Patchset already posted. http://thread.gmane.org/gmane.linux.kernel.cgroups/1376 Thanks. -- tejun