From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37F17C4CECE for ; Mon, 14 Oct 2019 09:44:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 178D320882 for ; Mon, 14 Oct 2019 09:44:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730997AbfJNJon (ORCPT ); Mon, 14 Oct 2019 05:44:43 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:45282 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730922AbfJNJon (ORCPT ); Mon, 14 Oct 2019 05:44:43 -0400 Received: from 79.184.254.38.ipv4.supernova.orange.pl (79.184.254.38) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.292) id 4cda1dedb0538358; Mon, 14 Oct 2019 11:44:41 +0200 From: "Rafael J. Wysocki" To: "Hernandez Lopez, Fabiola" Cc: "linux-pm@vger.kernel.org" , Srinivas Pandruvada Subject: Re: Frequency not returning to fixed value after AVX workload Date: Mon, 14 Oct 2019 11:44:41 +0200 Message-ID: <3340378.NBreQbsDsf@kreacher> In-Reply-To: <67737C20FC7E4D44B44817ABFA5B1DCE6EC01C77@CRSMSX104.amr.corp.intel.com> References: <67737C20FC7E4D44B44817ABFA5B1DCE6EC01C77@CRSMSX104.amr.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Friday, October 11, 2019 7:45:55 PM CEST Hernandez Lopez, Fabiola wrote: > Hi, > > We are seeing an unexpected behavior after applying AVX workloads. > After setting the CPU frequency to a fixed value with CPU Freq - userspace > governor and applying heavy AVX workloads, the CPU frequency is decreased > (as expected) but it never returns to the previously established value. How do you measure the frequency? > This does not happen on all cores, only on a single core. The only way to > return to the desired frequency is by setting it through the command line > again. What exactly do you do to get the expected frequency back? > We are wondering how can this change in frequency happen. Is the target frequency in the turbo range?