From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Doug Smythies" Subject: RE: CPUs do not go idle - excessive energy consumption Date: Thu, 19 Oct 2017 17:16:00 -0700 Message-ID: <000001d34938$9d012310$d7036930$@net> References: <000001d3436e$b9b58160$2d208420$@net> 2fn5expvk3OTt2fn6eOG4c 2gTken1Ckt1L52gTmefPL5 30gVe635D3OTt30gXeUUCy Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: Received: from cmta19.telus.net ([209.171.16.92]:50637 "EHLO cmta19.telus.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751046AbdJTAQG (ORCPT ); Thu, 19 Oct 2017 20:16:06 -0400 In-Reply-To: 30gVe635D3OTt30gXeUUCy Content-Language: en-ca Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "'Rafael J. Wysocki'" Cc: 'Linux PM' On 2017.10.13 07:10 Doug Smythies wrote: > On 2017.10.12 09:36 Doug Smythies wrote: >> On 2017.10.12 08:53 Rafael J. Wysocki wrote: >>> On Thu, Oct 12, 2017 at 5:28 PM, Doug Smythies wrote: >>>> >>>> I am observing higher than nominal processor package power consumption, under >>>> some conditions. The worst case, so far, was an extra 6.3 watts or 25%, however >>>> more typically it is between 0 and 4 watts (over 1 minute sampling intervals). >>>> >> ...[snip]... >> >>> For starters, you can try to apply this patch >>> https://patchwork.kernel.org/patch/9866841/ and see if it makes any >> difference. >> >> Oh darn, I missed the importance and relevance of that e-mail (but I did get it), >> which might have saved me a lot of time. >> It sounds like it is exactly the same issue. >> I'll try it as soon as I can either resolve the conflicts, or go back >> and apply it to whatever kernel version would result in no conflicts. >> >> I'll report back once I have some test results. I'll report back by replying to the above referenced e-mail. > The patch did not solve the problem. The patch did not work as it was sent. The changes I had to make will also be in the above mentioned reply. The patch still doesn't solve this particular problem. Merely disabling idle state 0 does solve the problem. I have been trying to demonstrate a downside to disabling idle state 0, and haven't found one. pipe-test is something we used before, but I don't see any difference on my computer. I have reviewed and reminded myself about the issues with the menu governor. > > Because the test results vary, and always have, it is hard to know for > certain of there was some improvement, but I did have a couple of 10 minute > tests with 0 occurrences (based on my arbitrary thresholds). A one hour > test had 530 occurrences. > > ... Doug