From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752030AbcEGGNX (ORCPT ); Sat, 7 May 2016 02:13:23 -0400 Received: from merlin.infradead.org ([205.233.59.134]:56123 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750936AbcEGGNW (ORCPT ); Sat, 7 May 2016 02:13:22 -0400 Date: Sat, 7 May 2016 08:13:10 +0200 From: Peter Zijlstra To: "Rafael J. Wysocki" Cc: Linux PM list , Linux Kernel Mailing List , Viresh Kumar , Srinivas Pandruvada , Steve Muckle , Ingo Molnar Subject: Re: [PATCH] sched/fair: Invoke cpufreq hooks for CONFIG_SMP unset Message-ID: <20160507061310.GA15728@worktop.ger.corp.intel.com> References: <6282396.VVEdgVYxO3@vostro.rjw.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6282396.VVEdgVYxO3@vostro.rjw.lan> 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 Fri, May 06, 2016 at 02:58:43PM +0200, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Commit 34e2c555f3e1 (cpufreq: Add mechanism for registering utilization > update callbacks) overlooked the fact that update_load_avg(), where > CFS invokes cpufreq utilization update hooks, becomes an empty stub for > CONFIG_SMP unset. In consequence, if CONFIG_SMP is not set, cpufreq > governors are never invoked from CFS and they do not have a chance to > evaluate CPU performace levels and update them often enough. Needless > to say, things don't work as expected then. > > Fix the problem by making the !CONFIG_SMP stub of update_load_avg() > invoke cpufreq update hooks too. > > Fixes: 34e2c555f3e1 (cpufreq: Add mechanism for registering utilization update callbacks) > Reported-by: Steve Muckle > Signed-off-by: Rafael J. Wysocki Rafael; feel free to push this through the pm tree. Acked-by: Peter Zijlstra (Intel)