Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932222Ab3JNRTJ (ORCPT ); Mon, 14 Oct 2013 13:19:09 -0400 Received: from service87.mimecast.com ([91.220.42.44]:46451 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932187Ab3JNRTH convert rfc822-to-8bit (ORCPT ); Mon, 14 Oct 2013 13:19:07 -0400 Date: Mon, 14 Oct 2013 18:19:09 +0100 From: Morten Rasmussen To: Arjan van de Ven Cc: Peter Zijlstra , "mingo@kernel.org" , "pjt@google.com" , "rjw@sisk.pl" , "dirk.j.brandewie@intel.com" , "vincent.guittot@linaro.org" , "alex.shi@linaro.org" , "preeti@linux.vnet.ibm.com" , "efault@gmx.de" , "corbet@lwn.net" , "tglx@linutronix.de" , Catalin Marinas , "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" Subject: Re: [RFC][PATCH 4/7] sched: power: Remove power capacity hints for kworker threads Message-ID: <20131014171909.GQ31039@e103034-lin> References: <1381511957-29776-1-git-send-email-morten.rasmussen@arm.com> <1381511957-29776-5-git-send-email-morten.rasmussen@arm.com> <20131014133356.GN3081@twins.programming.kicks-ass.net> <20131014161011.GO31039@e103034-lin> <525C1817.1050909@linux.intel.com> MIME-Version: 1.0 In-Reply-To: <525C1817.1050909@linux.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-OriginalArrivalTime: 14 Oct 2013 17:19:01.0825 (UTC) FILETIME=[79F01310:01CEC901] X-MC-Unique: 113101418190507301 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1376 Lines: 30 On Mon, Oct 14, 2013 at 05:13:11PM +0100, Arjan van de Ven wrote: > On 10/14/2013 9:10 AM, Morten Rasmussen wrote: > > On Mon, Oct 14, 2013 at 02:33:56PM +0100, Peter Zijlstra wrote: > >> On Fri, Oct 11, 2013 at 06:19:14PM +0100, Morten Rasmussen wrote: > >>> Removing power hints for kworker threads enables easier use of > >>> workqueues in the power driver late callback. That would otherwise > >>> lead to an endless loop unless it is prevented in the power driver. > >> > >> There's many kworker users; some of them actually consume lots of > >> cputime. Therefore how did you come to the conclusion that excepting all > >> users was the better choice of a little added complexity in the one > >> place where it actually matters? > > > > Agreed that it is not ideal. I will find a better solution for this > > problem. > > > > can you explain which architectures we're talking about that need this? > is it only old stuff, or is there anything current ? > For now I need it for the cpufreq wrapper governor. I hope it can be avoided for native power drivers, but I don't have a complete overview of all architectures yet. -- 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/