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_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 3E804C433F5 for ; Mon, 3 Sep 2018 15:15:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDC5D20862 for ; Mon, 3 Sep 2018 15:15:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDC5D20862 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 S1727368AbeICTgI (ORCPT ); Mon, 3 Sep 2018 15:36:08 -0400 Received: from mga11.intel.com ([192.55.52.93]:20641 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725949AbeICTgI (ORCPT ); Mon, 3 Sep 2018 15:36:08 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2018 08:15:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,325,1531810800"; d="scan'208";a="260345424" Received: from spandruv-mobl.amr.corp.intel.com ([10.254.97.104]) by fmsmga006.fm.intel.com with ESMTP; 03 Sep 2018 08:15:31 -0700 Message-ID: <9d2882f2877e52c611362dc7e3699eca1e715695.camel@linux.intel.com> Subject: Re: [PATCH] cpufreq: intel_pstate: Optimize IO boost in non HWP mode From: Srinivas Pandruvada To: Eero Tamminen , lenb@kernel.org, rjw@rjwysocki.net, viresh.kumar@linaro.org Cc: mgorman@techsingularity.net, currojerez@riseup.net, ggherdovich@suse.cz, peterz@infradead.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 03 Sep 2018 08:15:31 -0700 In-Reply-To: <1244c5d6-460e-0e0b-b7bf-a46e73327383@intel.com> References: <20180831172851.79812-1-srinivas.pandruvada@linux.intel.com> <1244c5d6-460e-0e0b-b7bf-a46e73327383@intel.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-1.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 Mon, 2018-09-03 at 18:10 +0300, Eero Tamminen wrote: > Hi, > > On 31.08.2018 20:28, Srinivas Pandruvada wrote: > ... > > As per testing Eero Tamminen, the results are comparable to the > > patchset > > https://patchwork.kernel.org/patch/10312259/ > > But he has to watch results for several days to check trend. > > It's close, but there is some gap compared to Francisco's version. > > (Because of the large variance on TDP limited devices, and factors > causing extra perf differences e.g. between boots, it's hard to give > exact number without having trends from several days / weeks. I > would > also need new version of Fransisco's patch set that applies to > latest > kernel like yours does.) > > > > Since here boost is getting limited to turbo and non turbo, we need > > some > > ways to adjust the fractions corresponding to max non turbo as > > well. It > > is much easier to use the actual P-state limits for boost instead > > of > > fractions. So here P-state io boost limit is applied on top of the > > P-state limit calculated via current algorithm by removing current > > io_wait boost calculation using fractions. > > > > Since we prefer to use common algorithm for all processor > > platforms, this > > change was tested on other client and sever platforms as well. All > > results > > were within the margin of errors. Results: > > https://bugzilla.kernel.org/attachment.cgi?id=278149 > > Good. > > Francisco, how well the listed PTS tests cover latency bound cases > you > were concerned about? [1] > > > - Eero > > [1] Fransisco was concerned that the patch: > * trade-off might regress latency bound cases (which I haven't > tested, I > tested only 3D throughput), and > * that it addressed only other of the sources of energy > inefficiencies > he had identified (which could explain slightly better 3D results > from > his more complex patch set). It is always possible to submit improvement patch later. Atleast this patch will reduce the usage of turbo. Thanks, Srinivas