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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 6559EC4CECE for ; Mon, 14 Oct 2019 21:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 448742067B for ; Mon, 14 Oct 2019 21:23:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730002AbfJNVXQ (ORCPT ); Mon, 14 Oct 2019 17:23:16 -0400 Received: from mga18.intel.com ([134.134.136.126]:21982 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729708AbfJNVXQ (ORCPT ); Mon, 14 Oct 2019 17:23:16 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Oct 2019 14:23:16 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,296,1566889200"; d="scan'208";a="194328026" Received: from spandruv-desk.jf.intel.com ([10.54.75.31]) by fmsmga008.fm.intel.com with ESMTP; 14 Oct 2019 14:23:15 -0700 Message-ID: Subject: Re: Frequency not returning to fixed value after AVX workload From: Srinivas Pandruvada To: "Hernandez Lopez, Fabiola" , "Rafael J. Wysocki" Cc: "linux-pm@vger.kernel.org" Date: Mon, 14 Oct 2019 14:23:15 -0700 In-Reply-To: <67737C20FC7E4D44B44817ABFA5B1DCE6EC020E9@CRSMSX104.amr.corp.intel.com> References: <67737C20FC7E4D44B44817ABFA5B1DCE6EC01C77@CRSMSX104.amr.corp.intel.com> <3340378.NBreQbsDsf@kreacher> <67737C20FC7E4D44B44817ABFA5B1DCE6EC020E9@CRSMSX104.amr.corp.intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-3.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Mon, 2019-10-14 at 21:11 +0000, Hernandez Lopez, Fabiola wrote: > How do you measure the frequency? Do whatever you are doing to get to your problem state and while doing the test run in another window: #turbostat Attach the output. Thanks, Srinivas > With lscpu. > > What exactly do you do to get the expected frequency back? > A script is used that sets the frequency with > /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed > > Is the target frequency in the turbo range? > No, the target frequency is the same as the base processor frequency: > 2.4GHz. The max turbo frequency for this CPU si 3.9 GHz. > This has been tested with turbo boost enabled and disabled. > > This behavior is very sporadic: < 10% > > Thanks, > Fabiola > > -----Original Message----- > From: Rafael J. Wysocki [mailto:rjw@rjwysocki.net] > Sent: Monday, October 14, 2019 4:45 AM > To: Hernandez Lopez, Fabiola > Cc: linux-pm@vger.kernel.org; Srinivas Pandruvada < > srinivas.pandruvada@linux.intel.com> > Subject: Re: Frequency not returning to fixed value after AVX > workload > > 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? > > >