Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754543AbdDLOnW (ORCPT ); Wed, 12 Apr 2017 10:43:22 -0400 Received: from foss.arm.com ([217.140.101.70]:45166 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752384AbdDLOnV (ORCPT ); Wed, 12 Apr 2017 10:43:21 -0400 Date: Wed, 12 Apr 2017 15:43:10 +0100 From: Patrick Bellasi To: Peter Zijlstra Cc: Tejun Heo , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Ingo Molnar , "Rafael J . Wysocki" , Paul Turner , Vincent Guittot , John Stultz , Todd Kjos , Tim Murray , Andres Oportus , Joel Fernandes , Juri Lelli , Chris Redpath , Morten Rasmussen , Dietmar Eggemann Subject: Re: [RFC v3 0/5] Add capacity capping support to the CPU controller Message-ID: <20170412144310.GB7572@e110439-lin> References: <1488292722-19410-1-git-send-email-patrick.bellasi@arm.com> <20170320145131.GA3623@htj.duckdns.org> <20170320172233.GA28391@e110439-lin> <20170410073622.2y6tnpcd2ssuoztz@hirez.programming.kicks-ass.net> <20170411175833.GI29455@e110439-lin> <20170412124822.GG3093@worktop> <20170412132741.GK29455@e110439-lin> <20170412143414.2c27dakhrydl2pqb@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170412143414.2c27dakhrydl2pqb@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1009 Lines: 27 On 12-Apr 16:34, Peter Zijlstra wrote: > On Wed, Apr 12, 2017 at 02:27:41PM +0100, Patrick Bellasi wrote: > > On 12-Apr 14:48, Peter Zijlstra wrote: > > > On Tue, Apr 11, 2017 at 06:58:33PM +0100, Patrick Bellasi wrote: > > > > > illustrated per your above points in that it affects both, while in > > > > > fact it actually modifies another metric, namely util_avg. > > > > > > > > I don't see it modifying in any direct way util_avg. > > > > > > The point is that clamps called 'capacity' are applied to util. So while > > > you don't modify util directly, you do modify the util signal (for one > > > consumer). > > > > Right, but this consumer (i.e. schedutil) it's already translating > > the util_avg into a next_freq (which ultimately it's a capacity). > > > > Thus, I don't see a big misfit in that code path to "filter" this > > translation with a capacity clamp. > > Still strikes me as odd though. Can you better elaborate on they why? -- #include Patrick Bellasi