From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932128AbcHBBth (ORCPT ); Mon, 1 Aug 2016 21:49:37 -0400 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36566 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755562AbcHBBt3 (ORCPT ); Mon, 1 Aug 2016 21:49:29 -0400 MIME-Version: 1.0 In-Reply-To: <20160802012209.GB9332@graphite.smuckle.net> References: <3752826.3sXAQIvcIA@vostro.rjw.lan> <3009663.9YcxTKseiO@vostro.rjw.lan> <20160802012209.GB9332@graphite.smuckle.net> From: "Rafael J. Wysocki" Date: Tue, 2 Aug 2016 03:37:02 +0200 X-Google-Sender-Auth: 6Y2XL4sK9jxdUZ1YImhg78aBaYU Message-ID: Subject: Re: [RFC][PATCH 5/7] cpufreq / sched: UUF_IO flag to indicate iowait condition To: Steve Muckle Cc: "Rafael J. Wysocki" , Linux PM list , Peter Zijlstra , Srinivas Pandruvada , Viresh Kumar , Linux Kernel Mailing List , Juri Lelli , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Aug 2, 2016 at 3:22 AM, Steve Muckle wrote: > On Mon, Aug 01, 2016 at 01:37:23AM +0200, Rafael J. Wysocki wrote: > ... >> For this purpose, define a new cpufreq_update_util() flag >> UUF_IO and modify enqueue_task_fair() to pass that flag to >> cpufreq_update_util() in the in_iowait case. That generally >> requires cpufreq_update_util() to be called directly from there, >> because update_load_avg() is not likely to be invoked in that >> case. > > I didn't follow why the cpufreq hook won't likely be called if > in_iowait is set? AFAICS update_load_avg() gets called in the second loop > and calls update_cfs_rq_load_avg (triggers the hook). In practice it turns out that in the majority of cases when in_iowait is set the second loop will not run. Thanks, Rafael