From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Doug Smythies" Subject: RE: [PATCH V4] intel_pstate: Use avg_pstate instead of current_pstate Date: Fri, 22 Apr 2016 08:18:49 -0700 Message-ID: <004701d19caa$4644c360$d2ce4a20$@net> References: <1459754617-8872-1-git-send-email-philippe.longepe@linux.intel.com> <1662176.YWLDtbbot1@vostro.rjw.lan> <1461286745.8946.203.camel@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cmta8.telus.net ([209.171.16.81]:46822 "EHLO cmta8.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754149AbcDVPSw (ORCPT ); Fri, 22 Apr 2016 11:18:52 -0400 In-Reply-To: Content-Language: en-ca Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: 'Srinivas Pandruvada' Cc: "'Rafael J. Wysocki'" , 'Philippe Longepe' , linux-pm@vger.kernel.org, 'Len Brown' , "'Rafael J. Wysocki'" , 'Stephane Gasparini' Srinivas, Recall a couple of months ago, on the "Increase hold-off time before busyness is scaled" thread, Stephane suggested we try applying this method on the get_target_pstate_use_performance branch of the intel_pstate driver, as opposed to just on the get_target_pstate_use_cpu_load branch. It didn't make any difference with respect to the hold-off time issue. However, I did spend considerable time testing it in other scenarios. It does somewhat temper the occasional tendency to suddenly have a ridiculously high scaled busy number with virtually no load (the same issue from the "[intel-pstate driver regression] processor frequency very high even if in idle" thread, that continued in https://bugzilla.kernel.org/show_bug.cgi?id=115771 ) I didn't find any significant regression, and did observe some small energy savings in some scenarios (admittedly, small enough to have possibly been simply test to test variations, and I didn't do enough tests to extract a definite trend). I am suggesting to consider extending the patch to get_target_pstate_use_performance also. ... Doug