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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 D7E8BC4363D for ; Tue, 22 Sep 2020 16:25:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DAAA239D2 for ; Tue, 22 Sep 2020 16:25:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726589AbgIVQZm (ORCPT ); Tue, 22 Sep 2020 12:25:42 -0400 Received: from foss.arm.com ([217.140.110.172]:46736 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726563AbgIVQZm (ORCPT ); Tue, 22 Sep 2020 12:25:42 -0400 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 2124E101E; Tue, 22 Sep 2020 09:25:42 -0700 (PDT) Received: from localhost (e108754-lin.cambridge.arm.com [10.1.199.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B5BB43F718; Tue, 22 Sep 2020 09:25:41 -0700 (PDT) Date: Tue, 22 Sep 2020 17:25:40 +0100 From: Ionela Voinescu To: Viresh Kumar Cc: rjw@rjwysocki.net, sudeep.holla@arm.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] cpufreq,cppc: fix issue when hotplugging out policy->cpu Message-ID: <20200922162540.GB796@arm.com> References: <20200903111955.31029-1-ionela.voinescu@arm.com> <20200904050604.yoar2c6fofcikipp@vireshk-i7> <20200904094303.GA10031@arm.com> <20200907061154.iiyaq4m3vjtrlkp4@vireshk-i7> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200907061154.iiyaq4m3vjtrlkp4@vireshk-i7> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi, Sorry for the delay, I just got back from holiday as well. On Monday 07 Sep 2020 at 11:41:54 (+0530), Viresh Kumar wrote: > On 04-09-20, 10:43, Ionela Voinescu wrote: > > Do you know why it was designed this way in the first place? > > No. > > > I assumed it was designed like this (per-cpu cppc_cpudata structures) to > > allow for the future addition of support for the HW_ALL CPPC coordination > > type. In that case you can still have PSD (dependency) domains but the > > desired performance controls would be per-cpu, with the coordination > > done in hardware/firmware. So, in the HW_ALL case you'd end up having > > different performance controls even for CPUs in the same policy. > > Currently the CPPC driver only supports SW_ANY which is the traditional > > cpufreq approach. > > Then the person who would add that feature will take care of fixing the issues > then. We should make sure we handle the current use-case optimally. And a > per-cpu thing isn't working well for that. > Okay, I'll follow your lead and remove the per-cpu structures. Thanks, Ionela. > -- > viresh