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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 412D0C3524D for ; Mon, 3 Feb 2020 08:59:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 15FDC20661 for ; Mon, 3 Feb 2020 08:59:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727865AbgBCI7i (ORCPT ); Mon, 3 Feb 2020 03:59:38 -0500 Received: from foss.arm.com ([217.140.110.172]:50776 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727466AbgBCI7i (ORCPT ); Mon, 3 Feb 2020 03:59:38 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 85E5030E; Mon, 3 Feb 2020 00:59:37 -0800 (PST) Received: from [192.168.1.19] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0E7D63F6CF; Mon, 3 Feb 2020 01:03:13 -0800 (PST) Subject: Re: [Patch v9 8/8] arm64: Enable averaging of thermal pressure for arm64 based SoCs To: Thara Gopinath , mingo@redhat.com, peterz@infradead.org, ionela.voinescu@arm.com, vincent.guittot@linaro.org, rui.zhang@intel.com, qperret@google.com, daniel.lezcano@linaro.org, viresh.kumar@linaro.org, rostedt@goodmis.org, will@kernel.org, catalin.marinas@arm.com, sudeep.holla@arm.com, juri.lelli@redhat.com, corbet@lwn.net Cc: linux-kernel@vger.kernel.org, amit.kachhap@gmail.com, javi.merino@kernel.org, amit.kucheria@verdurent.com References: <1580250967-4386-1-git-send-email-thara.gopinath@linaro.org> <1580250967-4386-9-git-send-email-thara.gopinath@linaro.org> From: Dietmar Eggemann Message-ID: Date: Mon, 3 Feb 2020 09:59:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <1580250967-4386-9-git-send-email-thara.gopinath@linaro.org> Content-Type: text/plain; charset=utf-8 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 On 28.01.20 23:36, Thara Gopinath wrote: > Enable CONFIG_HAVE_SCHED_THERMAL_PRESSURE in arm64 defconfig. > > Signed-off-by: Thara Gopinath > --- > arch/arm64/configs/defconfig | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig > index 0565a61..7a8145b 100644 > --- a/arch/arm64/configs/defconfig > +++ b/arch/arm64/configs/defconfig > @@ -5,6 +5,7 @@ CONFIG_NO_HZ_IDLE=y > CONFIG_HIGH_RES_TIMERS=y > CONFIG_PREEMPT=y > CONFIG_IRQ_TIME_ACCOUNTING=y > +CONFIG_HAVE_SCHED_THERMAL_PRESSURE=y I thought about this a bit more and maybe it's not a good idea to enable this by default. An erroneous thermal setup could have bad influence on the CPU capacities and hence on the performance without people understanding the cause of it. If they have to actively enable it, chances are higher that they also try to understand how higher thermal-cpufreq-X cooling states lead to CPU capacity reduction and possibly inversion (big-LITTLE swap). So if the thermal pressure feature is guarded by CONFIG_HAVE_SCHED_THERMAL_PRESSURE the thermal pressure related code in arch_topology.c (thermal_pressure, arch_set_thermal_pressure, topology_get_thermal_pressure) should too. Saves some text and data of arch_topology.o. Moreover Arm32 and Arm64 will be handled equally.