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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 89E35C43142 for ; Tue, 31 Jul 2018 19:07:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3921720894 for ; Tue, 31 Jul 2018 19:07:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3921720894 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732187AbeGaUs5 (ORCPT ); Tue, 31 Jul 2018 16:48:57 -0400 Received: from mga02.intel.com ([134.134.136.20]:1917 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732006AbeGaUs5 (ORCPT ); Tue, 31 Jul 2018 16:48:57 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 31 Jul 2018 12:07:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,428,1526367600"; d="scan'208";a="61313240" Received: from spandruv-mobl.amr.corp.intel.com ([10.254.15.88]) by orsmga008.jf.intel.com with ESMTP; 31 Jul 2018 12:07:08 -0700 Message-ID: <41b51613acbdaf59294f436af057753978908470.camel@linux.intel.com> Subject: Re: [PATCH 4/4] cpufreq: intel_pstate: enable boost for Skylake Xeon From: Srinivas Pandruvada To: Peter Zijlstra Cc: Eero Tamminen , Mel Gorman , Francisco Jerez , lenb@kernel.org, rjw@rjwysocki.net, ggherdovich@suse.cz, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, viresh.kumar@linaro.org, Chris Wilson , Tvrtko Ursulin , Joonas Lahtinen Date: Tue, 31 Jul 2018 12:07:08 -0700 In-Reply-To: <20180731150438.GE2458@hirez.programming.kicks-ass.net> References: <20180605214242.62156-1-srinivas.pandruvada@linux.intel.com> <20180605214242.62156-5-srinivas.pandruvada@linux.intel.com> <87bmarhqk4.fsf@riseup.net> <20180728123639.7ckv3ljnei3urn6m@techsingularity.net> <605cfcb3f315917c5970f452fab988ae1dc946ff.camel@linux.intel.com> <20180731150438.GE2458@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.3 (3.28.3-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-07-31 at 17:04 +0200, Peter Zijlstra wrote: > On Mon, Jul 30, 2018 at 07:06:21AM -0700, Srinivas Pandruvada wrote: > > On Mon, 2018-07-30 at 14:16 +0300, Eero Tamminen wrote: > > > Questions: > > > > > > * Does currently kernel CPU freq management have any idea which > > > IO > > > devices share TDP with the CPU cores? > > No. The requests we do to hardware is just indication only (HW can > > ignore it). The HW has a bias register to adjust and distribute > > power > > among users. > > We can have several other active device on servers beside CPU which > > when runs need extra power. So the HW arbitrates power. > > That's not entirely accurate AFAIK. "No" is accurate for Intel, but > the > ARM people have their IPA thing (not a beer): We also have that for using space programs (E.g. KBL-G). Thanks, Srinivas > > https://developer.arm.com/open-source/intelligent-power-allocation > > drivers/thermal/power_allocator.c > > which IIUC interacts with their cpufreq driver to disallow certain > OPP > states. > > And note that I discourage intel_pstate active mode.