From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH REPOST RFC cgroup/for-3.7] cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them Date: Thu, 13 Sep 2012 10:52:16 -0700 Message-ID: <20120913175216.GB7677@google.com> References: <20120910223125.GC7677@google.com> <20120910223355.GD7677@google.com> <20120913121629.GL7767@redhat.com> Mime-Version: 1.0 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=zEZKVZ4boCNZvLwj9T1V4IY/d8fYfS00B4G6XwXJDuc=; b=mZQJBg1cmStKTl+obj1zlTexxqmvj4K1sdTQKprXTG9k53AwkAzm/CXbbuwl60Z61J TWnC1FbuFeoumEUDMCG8JYKCuyGvQKA7N3Vx4qBr2IyWdPU3lI6UPgK8I2vmKACiyNFe I5TvMDEufqGeZ70PBxqKqC4cjgDDt4Kch3gG1VkL6BBrXitrqPPiLOf8OAjvv8B+UwZu c5bN8gjzehQHTHvbrMshAAbdGU9sLfAaih05UWttlZ9CC0igfjdaHYLES5I77CUXVB0D 4QY6b0czwjtcU4itxe7RO7+zS5xrqaxwD7pu4Wvc0Iv2lBETBjzVpcbo4+aPdBmOE22Z FWOw== Content-Disposition: inline In-Reply-To: <20120913121629.GL7767-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: "Daniel P. Berrange" Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Neil Horman , Michal Hocko , Paul Mackerras , "Aneesh Kumar K.V" , Arnaldo Carvalho de Melo , Johannes Weiner , Thomas Graf , "Serge E. Hallyn" , Paul Turner , Ingo Molnar , Vivek Goyal Hello, Daniel. On Thu, Sep 13, 2012 at 01:16:29PM +0100, Daniel P. Berrange wrote: > If you want application developers / users to understand this, then > you really need to update the Documentation/cgroups/cgroups.txt file > to provide suitable recommendations on use of hierarchies. As it > stands today it arguably encourages apps to make use of arbitrary > hierarchies. While some of the other docs (blkio-controller.txt) do > describe the limitations of their implementation, they don't ever > go as far as recommending against usage of hierarchies, which is > what you seem to be saying. > > Just printing warning messages in the logs with no docs to explain > the issues which cause the warnings is not friendly to users, and > IMHO will just lead people to ignore the warnings. Oh yeah, we definitely need to update the docs. No doubt about it. Will do. 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 S1755761Ab2IMRwX (ORCPT ); Thu, 13 Sep 2012 13:52:23 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:49916 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754504Ab2IMRwV (ORCPT ); Thu, 13 Sep 2012 13:52:21 -0400 Date: Thu, 13 Sep 2012 10:52:16 -0700 From: Tejun Heo To: "Daniel P. Berrange" Cc: linux-kernel@vger.kernel.org, containers@lists.linux-foundation.org, cgroups@vger.kernel.org, Neil Horman , Michal Hocko , Paul Mackerras , "Aneesh Kumar K.V" , Arnaldo Carvalho de Melo , Johannes Weiner , Thomas Graf , "Serge E. Hallyn" , Paul Turner , Ingo Molnar , Vivek Goyal Subject: Re: [PATCH REPOST RFC cgroup/for-3.7] cgroup: mark subsystems with broken hierarchy support and whine if cgroups are nested for them Message-ID: <20120913175216.GB7677@google.com> References: <20120910223125.GC7677@google.com> <20120910223355.GD7677@google.com> <20120913121629.GL7767@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120913121629.GL7767@redhat.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 Hello, Daniel. On Thu, Sep 13, 2012 at 01:16:29PM +0100, Daniel P. Berrange wrote: > If you want application developers / users to understand this, then > you really need to update the Documentation/cgroups/cgroups.txt file > to provide suitable recommendations on use of hierarchies. As it > stands today it arguably encourages apps to make use of arbitrary > hierarchies. While some of the other docs (blkio-controller.txt) do > describe the limitations of their implementation, they don't ever > go as far as recommending against usage of hierarchies, which is > what you seem to be saying. > > Just printing warning messages in the logs with no docs to explain > the issues which cause the warnings is not friendly to users, and > IMHO will just lead people to ignore the warnings. Oh yeah, we definitely need to update the docs. No doubt about it. Will do. Thanks. -- tejun