Received: by 2002:ac0:a5a7:0:0:0:0:0 with SMTP id m36-v6csp3673506imm; Tue, 17 Jul 2018 08:30:52 -0700 (PDT) X-Google-Smtp-Source: AAOMgpeP500KSeE5v0qmdZwNXKHA0C81ICVVJQduiGUKQwNjCYsJ4c5P/qpIOUs/1qs080yFoFQK X-Received: by 2002:a17:902:246a:: with SMTP id m39-v6mr2081780plg.141.1531841452588; Tue, 17 Jul 2018 08:30:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1531841452; cv=none; d=google.com; s=arc-20160816; b=XEFKOrIgS6GDfzdTgnScGNDvlqZTDRmfosAnLvtY7ALki+MJHHo4JLs8BsR5B66148 g5XiSKk53sZtTv3HbvgOtP8Bkzaroxm8offsbLMl1dkwG5bMDEOYrJfBcEebnAWOb+vJ st/j2VspZtaOnrWIx+Y/+g5wSr5OeClSQZBBa9OVWC+r2zOrPpjRVrZ5pcQv/uQkv/0D 4wpUuKYiNo5w6DCS0HggWLRi/eS5aiH6J6PYMRzddhasU0WtB9s5V0v1pLq9F8XI6ePh b8rcM7LP6G5o2VZe0lf3KvOAhvoqcDYXBkFGKurtVgkvYKBk/UJzGIDQspsVTdEblbmB C9RQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:subject:message-id:date:from :references:in-reply-to:mime-version:dkim-signature :arc-authentication-results; bh=6rj5FrBFGCJsvw7z2wi2yo8eEuPmSDqQIi3CBDf4+dk=; b=RPsuAujvTlSzom5SWeaxlxFUvBcXF7DvfuMKtGRrlhVVTxP8UFnZfkfll7jC8XL1Vt 3ZWUj65oYk16R4HBrUVitnF1/oms0suAIJolAG0qh+PGVI/OeOm74D5YnOa3r5FFcxeq hfRbBg8ADycSpkObGx4JXgxPpTbQBN4VT06lFZrYWZxdaMxxwEJiOW/IyhAA719Khtd1 92+e35Mz0qnn0JM5yOdixeRWJKCw3dfhPP0sAKOH8IGIvrja38ChwSjquo/QduTUR0gE ROW9WamztSBEnKRwLLdBo0OwiVlwRfwz5cHSL/Nto3gvGzCM1vzxHGIqawZ59m80dttr bY1Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=mUaB+EB2; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u186-v6si1162618pfu.263.2018.07.17.08.30.37; Tue, 17 Jul 2018 08:30:52 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=fail header.i=@gmail.com header.s=20161025 header.b=mUaB+EB2; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729700AbeGQQCc (ORCPT + 99 others); Tue, 17 Jul 2018 12:02:32 -0400 Received: from mail-oi0-f41.google.com ([209.85.218.41]:35987 "EHLO mail-oi0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729478AbeGQQCc (ORCPT ); Tue, 17 Jul 2018 12:02:32 -0400 Received: by mail-oi0-f41.google.com with SMTP id r16-v6so2802588oie.3; Tue, 17 Jul 2018 08:29:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=6rj5FrBFGCJsvw7z2wi2yo8eEuPmSDqQIi3CBDf4+dk=; b=mUaB+EB2GKACKrhesUYiFNDxQoxD84Y1yfnxDPoBhpbijk1/SOxEwMUVOFHbeHyTgu 2/QWSjLDP+sIX0F0yrOK9tD5OEKUOiNrwm5ZkNOIuMGiQGg6PtdazREser4C+hSU2941 fSi+i68nZIdBV/24WBLxHxFM/+usMQI7TEyx8R8Z9nbKfTTB+6oycl2rBQFwafES+Fit 4pX4BI+GJ5pFLmSVWLLCeGyHS/wYHMEmvAxXCoHXqjgpYuRcgKo+m+ab+jlWZ/dZWWVd asobvXS+uygP6ebMs58XQj6TA2oB+Zv+GfV6D4sl9hbNZ/FRKXrVXOylhyZLurDZFpV+ nQMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=6rj5FrBFGCJsvw7z2wi2yo8eEuPmSDqQIi3CBDf4+dk=; b=P9MzPfffLMt1aVAt4ErXBm2F6idlv9qYCvfpW36xCmpDMcZQPU94qOEkYkm5to3m4y kODwIkmovN75vGJ6JVY+iZsv2fAC/6O9yQxN+PZQd4k3UBUldfCS+L18eGRN+E6o0JT5 afbtxVJY1OOQjP+lJR5nLK88RelfMcGJOLNWRsofORL0wayc0D3kItppfywGvaj13+nk z9XZdyUTn6EfOuS+lCXCYRYNROlz0ixgbvCichMvALAwjUhSHool8Mol+rDWxoWVCjkC PQUPnL3lRkDgnEdNclU5/0YpsjvI6UHadgDTCtbqaHV6pf1eV9QPu+FEZ4/1vv7oEb4r Q50w== X-Gm-Message-State: AOUpUlEd7WC7KVmwsMNwJ5NQ6SMDsUN5FB7k6Qe7I6py0F0ZrG3hWgM9 Dc+ax9nXRNQjK7tFy2FICoT4q+/B8Cg5+JeXlK0= X-Received: by 2002:aca:ecd0:: with SMTP id k199-v6mr2319103oih.227.1531841361811; Tue, 17 Jul 2018 08:29:21 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a9d:63d2:0:0:0:0:0 with HTTP; Tue, 17 Jul 2018 08:29:21 -0700 (PDT) In-Reply-To: <20180717140336.ayovaz4ksdlak6bb@suselix> References: <20180717065048.74mmgk4t5utjaa6a@suselix> <20180717092721.onkaf3qsu7te6syi@suselix> <20180717093620.ym6phfmr3rfvsxyo@suselix> <3724084.DyflrVPzDS@aspire.rjw.lan> <20180717102136.snayvzmv2h3dcwiq@suselix> <20180717140336.ayovaz4ksdlak6bb@suselix> From: "Rafael J. Wysocki" Date: Tue, 17 Jul 2018 17:29:21 +0200 X-Google-Sender-Auth: MCVymb2HzTJ9oaIPvqbsZBosHi8 Message-ID: Subject: Re: Commit 554c8aa8ecad causing severe performance degression with pcc-cpufreq To: Andreas Herrmann Cc: "Rafael J. Wysocki" , "Rafael J. Wysocki" , Peter Zijlstra , Frederic Weisbecker , Viresh Kumar , Linux PM , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2018 at 4:03 PM, Andreas Herrmann wrote: > On Tue, Jul 17, 2018 at 12:21:36PM +0200, Andreas Herrmann wrote: >> On Tue, Jul 17, 2018 at 12:09:21PM +0200, Rafael J. Wysocki wrote: > > ---8<--- > >> > OK, the patch is below. >> > >> > First, I hope that if "Collaborative Power Control" is disabled, it will >> > simply hide the PCCH object and so intel_pstate will still not load then. >> >> PCCH is hidden in that case. >> >> > The main question basically is what the OS is expected to do if >> > "Dynamic Power Savings Mode" is set. If we are *expected* to use >> > the PCC interface then, intel_pstate may not work in that case, but >> > I suspect that the PCC interface allows extra energy to be saved >> > over what is possible without it. >> >> I'll test it and see what happens. > > I've tested it on top of v4.18-rc5-36-g30b06abfb92b. intel_pstate now > loads instead of pcc-cpufreq and system looks stable. > > When disabling "Collaborative Power Control" no cpufreq driver is loaded > (as expected). > > Performance (with kernbench) is as expected (always better than any > brew of pcc-cpufreq + misc modifications to this driver + partial > rollback of commit 554c8aa8ecad). > > If you like you can add either Tested-by or > Reviewed-by: Andreas Herrmann > > I think this patch should be tagged for 4.17-stable. OK, thank you for testing!