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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 CF44EC3B18C for ; Thu, 13 Feb 2020 15:57:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF2332073C for ; Thu, 13 Feb 2020 15:57:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728357AbgBMP4u (ORCPT ); Thu, 13 Feb 2020 10:56:50 -0500 Received: from foss.arm.com ([217.140.110.172]:47890 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727973AbgBMPZZ (ORCPT ); Thu, 13 Feb 2020 10:25:25 -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 3E55A328; Thu, 13 Feb 2020 07:25:24 -0800 (PST) Received: from [10.37.12.116] (unknown [10.37.12.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 130463F68E; Thu, 13 Feb 2020 07:25:13 -0800 (PST) Subject: Re: [PATCH v2 1/4] PM / EM: add devices to Energy Model To: Dietmar Eggemann , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-omap@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-imx@nxp.com Cc: Morten.Rasmussen@arm.com, Chris.Redpath@arm.com, ionela.voinescu@arm.com, javi.merino@arm.com, cw00.choi@samsung.com, b.zolnierkie@samsung.com, rjw@rjwysocki.net, sudeep.holla@arm.com, viresh.kumar@linaro.org, nm@ti.com, sboyd@kernel.org, rui.zhang@intel.com, amit.kucheria@verdurent.com, daniel.lezcano@linaro.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, rostedt@goodmis.org, qperret@google.com, bsegall@google.com, mgorman@suse.de, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, kernel@pengutronix.de, khilman@kernel.org, agross@kernel.org, bjorn.andersson@linaro.org, robh@kernel.org, matthias.bgg@gmail.com, steven.price@arm.com, tomeu.vizoso@collabora.com, alyssa.rosenzweig@collabora.com, airlied@linux.ie, daniel@ffwll.ch, liviu.dudau@arm.com, lorenzo.pieralisi@arm.com, patrick.bellasi@matbug.net References: <20200206134640.11367-1-lukasz.luba@arm.com> <20200206134640.11367-2-lukasz.luba@arm.com> <62a54ec9-0491-367d-0a36-7ea32c449acc@arm.com> From: Lukasz Luba Message-ID: <6b1921bb-42c8-999f-abfa-5682e73015d5@arm.com> Date: Thu, 13 Feb 2020 15:25:11 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <62a54ec9-0491-367d-0a36-7ea32c449acc@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On 2/13/20 10:59 AM, Dietmar Eggemann wrote: > On 06/02/2020 14:46, lukasz.luba@arm.com wrote: >> From: Lukasz Luba > > [..] > >> @@ -26,7 +28,7 @@ framework, and interested clients reading the data from it:: > > s/::/: ? > >> | Thermal (IPA) | | Scheduler (EAS) | | Other | >> +---------------+ +-----------------+ +---------------+ >> | | em_pd_energy() | >> - | | em_cpu_get() | >> + | em_get_pd() | em_cpu_get() | >> +---------+ | +---------+ > > em_get_pd() and em_cpu_get()? Why not em_pd_get()? em_cpu_get() is a > specific em_get_pd(). right? Yes. I will rename 'em_get_pd' to 'em_pd_get' > > [...] > >> @@ -85,13 +89,20 @@ API. >> 2.3 Accessing performance domains >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ >> >> +There is two API functions which provide the access to the energy model: >> +em_cpu_get() which takes CPU id as an argument and em_get_pd() with device >> +pointer as an argument. It depends on the subsystem which interface it is >> +going to use, but in case of CPU devices both functions return the same >> +performance domain. > > There is probably a reason why we need this specific function for CPU > devices? The reason should be described. People might ask why > em_get_pd() is not sufficient. True, good point. I will extend the comment in em_cpu_get(). > > [...] > >> - * A "performance domain" represents a group of CPUs whose performance is >> - * scaled together. All CPUs of a performance domain must have the same >> - * micro-architecture. Performance domains often have a 1-to-1 mapping with >> - * CPUFreq policies. >> + * In case of CPU device, a "performance domain" represents a group of CPUs >> + * whose performance is scaled together. All CPUs of a performance domain >> + * must have the same micro-architecture. Performance domains often have >> + * a 1-to-1 mapping with CPUFreq policies. >> + * In case of other devices the 'priv' field is unused. >> */ >> struct em_perf_domain { >> - struct em_cap_state *table; >> - int nr_cap_states; >> - unsigned long cpus[0]; >> + struct em_perf_state *table; >> + int nr_perf_states; >> + void *priv; > > In case you go back to the variable length field plus type field to > distingush EM devices, keep cpus[0] as the name. OK, I will. > > [..] > >> /** >> - * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain >> + * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. >> + domain > > Why this change? hmmm, that's odd, maybe there was 'device' then I changed it back to 'CPUs' but forgot to move the 'domain' to the old place. > > [...] > >> @@ -141,12 +210,12 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, >> */ >> opp_eff = freq / power; >> if (opp_eff >= prev_opp_eff) >> - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n", >> - cpu, i, i - 1); >> + dev_warn(dev, "energy_model: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n", > > s/energy_model/EM ? OK, I will rename them in all places. Thank you for the review. Regards, Lukasz