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 721B8FD21E1 for ; Mon, 30 Jul 2018 08:22:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 209D120870 for ; Mon, 30 Jul 2018 08:22:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 209D120870 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=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 S1726548AbeG3J4l (ORCPT ); Mon, 30 Jul 2018 05:56:41 -0400 Received: from mga04.intel.com ([192.55.52.120]:28801 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726497AbeG3J4l (ORCPT ); Mon, 30 Jul 2018 05:56:41 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 30 Jul 2018 01:22:50 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,422,1526367600"; d="scan'208";a="77109603" Received: from speedy.fi.intel.com (HELO [10.237.72.71]) ([10.237.72.71]) by orsmga001.jf.intel.com with ESMTP; 30 Jul 2018 01:22:17 -0700 Subject: Re: [PATCH 4/4] cpufreq: intel_pstate: enable boost for Skylake Xeon To: Srinivas Pandruvada , Francisco Jerez , lenb@kernel.org, rjw@rjwysocki.net, mgorman@techsingularity.net Cc: peterz@infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, viresh.kumar@linaro.org, ggherdovich@suse.cz, Chris Wilson , Tvrtko Ursulin , Joonas Lahtinen References: <20180605214242.62156-1-srinivas.pandruvada@linux.intel.com> <20180605214242.62156-5-srinivas.pandruvada@linux.intel.com> <87bmarhqk4.fsf@riseup.net> <3afad4b13370fe0ba6ed5020f86ce1b8ff46c603.camel@linux.intel.com> From: Eero Tamminen Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Message-ID: Date: Mon, 30 Jul 2018 11:33:25 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <3afad4b13370fe0ba6ed5020f86ce1b8ff46c603.camel@linux.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 28.07.2018 17:14, Srinivas Pandruvada wrote: > On Fri, 2018-07-27 at 22:34 -0700, Francisco Jerez wrote: >> Srinivas Pandruvada writes: >> >>> Enable HWP boost on Skylake server and workstations. >>> >> >> Please revert this series, it led to significant energy usage and >> graphics performance regressions [1]. > Which SKX platform is targeted to graphics? Patch that Chris pointed out is this: +static const struct x86_cpu_id intel_pstate_hwp_boost_ids[] = { + ICPU(INTEL_FAM6_SKYLAKE_X, core_funcs), + ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, core_funcs), + {} +}; The regressing platforms in our test system were: - SKL 6600K i5 / GT2 - SKL 6770HQ i7 / GT4e SKL-U i5 / GT3e device wasn't impacted, so I assume U devices don't match INTEL_FAM6_SKYLAKE_DESKTOP. - Eero >> The reasons are roughly the ones >> we discussed by e-mail off-list last April: This causes the >> intel_pstate >> driver to decrease the EPP to zero > No. You didn't check this series. We are not using EPP at all. > The boost mechanism used here is not boost to max. > > Thanks, > Srinivas > >> when the workload blocks on IO >> frequently enough, which for the regressing benchmarks detailed in >> [1] >> is a symptom of the workload being heavily IO-bound, which means they >> won't benefit at all from the EPP boost since they aren't >> significantly >> CPU-bound, and they will suffer a decrease in parallelism due to the >> active CPU core using a larger fraction of the TDP in order to >> achieve >> the same work, causing the GPU to have a lower power budget >> available, >> leading to a decrease in system performance. >> >> You may want to give a shot to my previous suggestion of using [2] in >> order to detect whether the system is IO-bound, which you can use as >> an >> indicator that the optimization implemented in this series cannot >> possibly improve performance and can be expected to hurt energy >> usage. >> >> Thanks. >> >> [1] https://bugs.freedesktop.org/show_bug.cgi?id=107410 >> [2] https://patchwork.kernel.org/patch/10312259/ >> >>> Reported-by: Mel Gorman >>> Tested-by: Giovanni Gherdovich >>> Signed-off-by: Srinivas Pandruvada >> .com> >>> --- >>> drivers/cpufreq/intel_pstate.c | 10 ++++++++++ >>> 1 file changed, 10 insertions(+) >>> >>> diff --git a/drivers/cpufreq/intel_pstate.c >>> b/drivers/cpufreq/intel_pstate.c >>> index 70bf63bb4e0e..01c8da1f99db 100644 >>> --- a/drivers/cpufreq/intel_pstate.c >>> +++ b/drivers/cpufreq/intel_pstate.c >>> @@ -1794,6 +1794,12 @@ static const struct x86_cpu_id >>> intel_pstate_cpu_ee_disable_ids[] = { >>> {} >>> }; >>> >>> +static const struct x86_cpu_id intel_pstate_hwp_boost_ids[] >>> __initconst = { >>> + ICPU(INTEL_FAM6_SKYLAKE_X, core_funcs), >>> + ICPU(INTEL_FAM6_SKYLAKE_DESKTOP, core_funcs), >>> + {} >>> +}; >>> + >>> static int intel_pstate_init_cpu(unsigned int cpunum) >>> { >>> struct cpudata *cpu; >>> @@ -1824,6 +1830,10 @@ static int intel_pstate_init_cpu(unsigned >>> int cpunum) >>> intel_pstate_disable_ee(cpunum); >>> >>> intel_pstate_hwp_enable(cpu); >>> + >>> + id = x86_match_cpu(intel_pstate_hwp_boost_ids); >>> + if (id) >>> + hwp_boost = true; >>> } >>> >>> intel_pstate_get_cpu_pstates(cpu); >>> -- >>> 2.13.6