From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout12.his.huawei.com (canpmsgout12.his.huawei.com [113.46.200.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C03226CE23; Tue, 18 Nov 2025 08:45:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.227 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763455520; cv=none; b=TvNat8TLmc4vPcLewMQjaF48NF5aXLDTg5Xd34PM5Ol0eqKJ1NEaNfqTHb0o+XlCB3RoJYCodbQNJP4jnON0DQKWPw70vO9m7v975Ur6IqKNB4srce8dBAQqPOsWDjtkGFs5WdzvFmmXWjwTGF0BS/jVTwuBT2/biJgyESBbSzs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763455520; c=relaxed/simple; bh=ChTxPLFlWr1lSX3akZs188rfnwDUuv11s05nw4ZOZIg=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=WyQjcJ1hwV9bu2PksELfmkkq/D9a1S9qBL3mnIfssMbXQn+mE/+atfl3UtfY3ij336vUr9GZNJMrFQfsQN/et5SoV4UW13rCbHu7X5sS2SN+EYLAPVgFkLy8KO74GLv9+uwWVv5APHkeS6PybbgobvhOhYEn5nqf8AGfZ3tCQKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com; spf=pass smtp.mailfrom=hisilicon.com; arc=none smtp.client-ip=113.46.200.227 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hisilicon.com Received: from mail.maildlp.com (unknown [172.19.88.163]) by canpmsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4d9dSH6kFkznTvj; Tue, 18 Nov 2025 16:43:43 +0800 (CST) Received: from kwepemf200017.china.huawei.com (unknown [7.202.181.10]) by mail.maildlp.com (Postfix) with ESMTPS id 02B1C18001B; Tue, 18 Nov 2025 16:45:12 +0800 (CST) Received: from [10.67.121.58] (10.67.121.58) by kwepemf200017.china.huawei.com (7.202.181.10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 18 Nov 2025 16:45:10 +0800 Message-ID: <14efdd1b-677d-488b-8dce-b1131d6928ae@hisilicon.com> Date: Tue, 18 Nov 2025 16:45:10 +0800 Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 0/8] Enhanced autonomous selection and improvements To: Sumit Gupta , , , , , , , , , , , , , , , , , , CC: , , , , , , , References: <20251105113844.4086250-1-sumitg@nvidia.com> Content-Language: en-US From: Jie Zhan In-Reply-To: <20251105113844.4086250-1-sumitg@nvidia.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemf200017.china.huawei.com (7.202.181.10) On 11/5/2025 7:38 PM, Sumit Gupta wrote: > This patch series enhances the ACPI CPPC CPUFREQ driver with > comprehensive support for autonomous performance selection, expanded > runtime control interfaces and improvements. > > It adds support for below: > - Expose sysfs to read/write the Minimum/Maximum Performance Registers > using frequency (kHz), with internal conversion to performance values. > Also, update the policy min/max accordingly. > /sys/.../cpufreq/policy*/min_perf and max_perf > > - Expose sysfs to read/write the Performance Limited Register. > /sys/.../cpufreq/policy*/perf_limited > > - When toggling autonomous selection, synchronize the policy limits > by updating the policy min/max. > > - System-wide autonomous mode configuration via 'auto_sel_mode' boot > parameter. Mode can be switched dynamically on individual CPUs. > > - Generic sysfs helper functions to reduce code duplication. Hi Sumit, My biggest question is what do we design for users to use all this CPPC autosel stuff in the cppc_cpufreq driver? Is it just exposing most of the related interfaces through sysfs and then we let userspace to play with it (probably with a userspace tool) or something like the amd_pstate_epp driver? Since this is quite a large change, we may need a guideline of how it's gonna be used so we would have a clue of how it should be made. Cheers, Jie