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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AF21C77B73 for ; Tue, 30 May 2023 09:54:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230527AbjE3Jyb (ORCPT ); Tue, 30 May 2023 05:54:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34708 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231299AbjE3JyK (ORCPT ); Tue, 30 May 2023 05:54:10 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 81D37FF; Tue, 30 May 2023 02:53:57 -0700 (PDT) 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 7DFC6AB6; Tue, 30 May 2023 02:54:42 -0700 (PDT) Received: from [192.168.178.6] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 05EF13F67D; Tue, 30 May 2023 02:53:54 -0700 (PDT) Message-ID: <93afb0fd-6226-4b0d-380a-182ecf028b34@arm.com> Date: Tue, 30 May 2023 11:53:53 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [PATCH v2 12/17] PM: EM: Add argument to get_cost() for runtime modification Content-Language: en-US To: Lukasz Luba , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, rafael@kernel.org Cc: rui.zhang@intel.com, amit.kucheria@verdurent.com, amit.kachhap@gmail.com, daniel.lezcano@linaro.org, viresh.kumar@linaro.org, len.brown@intel.com, pavel@ucw.cz, Pierre.Gondois@arm.com, ionela.voinescu@arm.com, rostedt@goodmis.org, mhiramat@kernel.org References: <20230512095743.3393563-1-lukasz.luba@arm.com> <20230512095743.3393563-13-lukasz.luba@arm.com> From: Dietmar Eggemann In-Reply-To: <20230512095743.3393563-13-lukasz.luba@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/05/2023 11:57, Lukasz Luba wrote: > The Energy Model (EM) supports runtime modifications. Let also the > artificial EM use this new feature and allow to update the 'cost' values > at runtime. When the artificial EM is used there is a need to provide > two callbacks: get_cost() and update_power(), not only the last one. > > Update also CPPC driver code, since the new argument is needed there > to compile properly and register EM. Is there a real use case behind this? It can't be mobile which IMHO drivers the rest of the 'Runtime modifiable EM' feature. Do we know of any machine using the artificial EM. And do they care about EM matching workload or static power? [...]