Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752685AbaJJJHt (ORCPT ); Fri, 10 Oct 2014 05:07:49 -0400 Received: from casper.infradead.org ([85.118.1.10]:45109 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751744AbaJJJHr (ORCPT ); Fri, 10 Oct 2014 05:07:47 -0400 Date: Fri, 10 Oct 2014 11:07:43 +0200 From: Peter Zijlstra To: Vincent Guittot Cc: Morten Rasmussen , "mingo@redhat.com" , Dietmar Eggemann , Paul Turner , Benjamin Segall , Nicolas Pitre , Mike Turquette , "rjw@rjwysocki.net" , linux-kernel Subject: Re: [PATCH 1/7] sched: Introduce scale-invariant load tracking Message-ID: <20141010090743.GE10832@worktop.programming.kicks-ass.net> References: <1411403047-32010-1-git-send-email-morten.rasmussen@arm.com> <1411403047-32010-2-git-send-email-morten.rasmussen@arm.com> <20140925172343.GX23693@e103034-lin> <20141002203428.GI2849@worktop.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 08, 2014 at 01:38:40PM +0200, Vincent Guittot wrote: > I have in mind some system where the max achievable freq of a core > depends of how many cores are running simultaneously because of some > HW constraint like max current. In this case, the CPU might not reach > max frequency even with an always running task. > Then, beside frequency scaling, their is the uarch invariance that is > introduced by patch 4 that will generate similar behavior of the load. This is a 'common' issue. x86 and powerpc also suffer this. It can be the result of either thermal or power thresholds. -- 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/