From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758786Ab2CMRZ7 (ORCPT ); Tue, 13 Mar 2012 13:25:59 -0400 Received: from casper.infradead.org ([85.118.1.10]:42815 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758691Ab2CMRZ5 convert rfc822-to-8bit (ORCPT ); Tue, 13 Mar 2012 13:25:57 -0400 Message-ID: <1331659537.18960.84.camel@twins> Subject: Re: [RFD] cgroup: about multiple hierarchies From: Peter Zijlstra To: Vivek Goyal Cc: Tejun Heo , Li Zefan , containers@lists.linux-foundation.org, cgroups@vger.kernel.org, Andrew Morton , Kay Sievers , Lennart Poettering , Frederic Weisbecker , linux-kernel@vger.kernel.org, Michal Schmidt Date: Tue, 13 Mar 2012 18:25:37 +0100 In-Reply-To: <20120313141032.GD29169@redhat.com> References: <20120221211938.GE12236@google.com> <20120312221050.GG23255@google.com> <1331590938.18960.57.camel@twins> <20120312222817.GI23255@google.com> <1331591568.18960.61.camel@twins> <20120312223944.GJ23255@google.com> <1331592241.18960.64.camel@twins> <20120312230416.GM23255@google.com> <20120313141032.GD29169@redhat.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 Tue, 2012-03-13 at 10:10 -0400, Vivek Goyal wrote: > Implementing hierarchy is a pain and is expensive at run time. Yeah, suck it up :-) I would really rather we mandate one implementation standard for controllers for the sake of consistency and uniformity. A direct result of doing away with the multiple hierarchy crap is that all controllers are co-mounted. Allowing differences like this just doesn't make any sense. So either we drop full hierarchy support from all controllers or we deprecate and remove all non-hierarchical controllers. I'm fine with either, but I'm not fine with with the half-arsed solutions proposed here.