Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753841AbcDIMbZ (ORCPT ); Sat, 9 Apr 2016 08:31:25 -0400 Received: from mail-lf0-f65.google.com ([209.85.215.65]:35490 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753697AbcDIMbY (ORCPT ); Sat, 9 Apr 2016 08:31:24 -0400 MIME-Version: 1.0 In-Reply-To: <20160409110729.GS3448@twins.programming.kicks-ass.net> References: <1460092854.4051.1.camel@gmail.com> <20160408064510.GK3448@twins.programming.kicks-ass.net> <1460098254.5582.17.camel@gmail.com> <2428384.mEkP3EOpsR@vostro.rjw.lan> <20160409110729.GS3448@twins.programming.kicks-ass.net> Date: Sat, 9 Apr 2016 14:31:22 +0200 X-Google-Sender-Auth: 0CuB39eqz8pgy9z9HeTOJ-9Qor0 Message-ID: Subject: Re: [regression] cross core scheduling frequency drop bisected to 0c313cb20732 From: "Rafael J. Wysocki" To: Peter Zijlstra Cc: "Rafael J. Wysocki" , Mike Galbraith , "Rafael J. Wysocki" , LKML , Linux PM list , Doug Smythies , Rik van Riel Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 749 Lines: 20 On Sat, Apr 9, 2016 at 1:07 PM, Peter Zijlstra wrote: > On Fri, Apr 08, 2016 at 10:59:59PM +0200, Rafael J. Wysocki wrote: >> On Friday, April 08, 2016 08:50:54 AM Mike Galbraith wrote: >> > On Fri, 2016-04-08 at 08:45 +0200, Peter Zijlstra wrote: >> > >> > > Cute, I thought you used governor=performance for your runs? >> > >> > I do, and those numbers are with it thus set. >> >> Well, this is a trade-off. >> >> 4.5 introduced a power regression here so this one goes back to the previous >> state of things. > > Just for my elucidation; how can gov=performance have a 'power' > regression? Because of what is used as the "default" idle state most of the time. C1 was used before 4.5 and that changed to polling in 4.5.