Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756469AbbDOPsQ (ORCPT ); Wed, 15 Apr 2015 11:48:16 -0400 Received: from mail-yk0-f170.google.com ([209.85.160.170]:36635 "EHLO mail-yk0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753614AbbDOPsF (ORCPT ); Wed, 15 Apr 2015 11:48:05 -0400 Date: Wed, 15 Apr 2015 11:48:02 -0400 From: Tejun Heo To: "Serge E. Hallyn" Cc: Peter Zijlstra , Preeti U Murthy , svaidy@linux.vnet.ibm.com, nacc@linux.vnet.ibm.com, rjw@rjwysocki.net, linux-kernel@vger.kernel.org, lizefan@huawei.com, anton@samba.org, bharata@linux.vnet.ibm.com, cgroups@vger.kernel.org, paulmck@linux.vnet.ibm.com, mingo@kernel.org Subject: Re: [PATCH V2] cpuset: Add knob to make allowed masks hotplug invariant on legacy hierarchy Message-ID: <20150415154802.GB30337@htj.duckdns.org> References: <20150410141118.11284.36206.stgit@preeti.in.ibm.com> <20150411083537.GR27490@worktop.programming.kicks-ass.net> <20150413070117.GX24151@twins.programming.kicks-ass.net> <552BB3A5.9060905@linux.vnet.ibm.com> <20150413144311.GF5029@twins.programming.kicks-ass.net> <552E4E41.3030008@linux.vnet.ibm.com> <20150415150302.GA25089@mail.hallyn.com> <20150415151926.GS23123@twins.programming.kicks-ass.net> <20150415153035.GA25390@mail.hallyn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150415153035.GA25390@mail.hallyn.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1317 Lines: 31 On Wed, Apr 15, 2015 at 10:30:35AM -0500, Serge E. Hallyn wrote: > On Wed, Apr 15, 2015 at 05:19:26PM +0200, Peter Zijlstra wrote: > > On Wed, Apr 15, 2015 at 10:03:02AM -0500, Serge E. Hallyn wrote: > > > > > Peter, is the question "why can't we just use the unified hierarchy for > > > cpusets"? > > > > No, the question is why can't you use the unified hierarchy cpuset > > semantics -- without the actual unified hierarchy stuff. > > Ok - that I don't know the answer to. Does sound like it would > simplify things, reduce # of sets of semantics. What'd be the reason for not using the unified hierarchy tho? The adaptable required isn't that big and the patchset already proposes significant amount of behavior change. Sure it'd be a bit more hassle but does that really justify introducing yet another operation mode? This is why unified hierarchy is being added in the first place. One can argue "but *I* just need this specific part changed" but allowing combinations of all those little variations is gonna lead us to a hellish place. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/