From patchwork Fri Dec 6 13:55:56 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beata Michalska X-Patchwork-Id: 13897261 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 456A8E77173 for ; Fri, 6 Dec 2024 13:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=OymvNbNhhpKoEMjUDLtKhe5sk4PAYvIpK66BpSAfOXk=; b=gLE3UFZnS0mArOJSoyyyOq+lHo R4uuYfc00zXl0M0j5gKB9oIn/7fENc68jMwlcsnSr9oOKgizjZXoxXY+TepxMsV+vu0s0G3l8uJB3 HbCwxjR7wIDEHUUVkUbfTL0xMCmTaPz0byvfYd/bSbvBkic/x1dPT3k6hyV+xoD3i8zxpPDDn6TAq c4SUVTGNggy0n3cg4mNb8KsjGyRYb2sFj+CghKvr/AX7X7K2oqiugpDojamtLxykY4d56TtwBmpEA n5SF0S2jjWylH0j/5Esmf+4yAvNK0tx9IUYFxPgnQX+IH+N8Cjzg32Oyp3LZmGx/iH1uwBYae5mJr l1lPC9+g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tJYqs-00000001nt1-2RIE; Fri, 06 Dec 2024 13:58:38 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tJYos-00000001nIJ-27tN for linux-arm-kernel@lists.infradead.org; Fri, 06 Dec 2024 13:56:36 +0000 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 48F9CFEC; Fri, 6 Dec 2024 05:56:59 -0800 (PST) Received: from e125905.cambridge.arm.com (e125905.cambridge.arm.com [10.1.194.73]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 2469B3F71E; Fri, 6 Dec 2024 05:56:28 -0800 (PST) From: Beata Michalska To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pm@vger.kernel.org, ionela.voinescu@arm.com, sudeep.holla@arm.com, will@kernel.org, catalin.marinas@arm.com, rafael@kernel.org, viresh.kumar@linaro.org Cc: sumitg@nvidia.com, yang@os.amperecomputing.com, vanshikonda@os.amperecomputing.com, lihuisong@huawei.com, zhanjie9@hisilicon.com, Jonathan Corbet , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H . Peter Anvin" , Phil Auld , x86@kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v8 0/4] Add support for AArch64 AMUv1-based average freq Date: Fri, 6 Dec 2024 13:55:56 +0000 Message-Id: <20241206135600.4083965-1-beata.michalska@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241206_055634_629831_CDCBE984 X-CRM114-Status: GOOD ( 17.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi All, This series adds support for obtaining an average CPU frequency based on a hardware provided feedback. The average frequency is being exposed via dedicated yet optional cpufreq sysfs attribute - cpuinfo_avg_freq. The architecture specific bits are being provided for AArch64, caching on existing implementation for FIE and AMUv1 support: the frequency scale factor, updated on each sched tick, serving as a base for retrieving the frequency for a given CPU, representing an average frequency reported between the ticks. The changes have been rather lightly (due to some limitations) tested on an FVP model. Note that [PATCH 2/4] arm64: amu: Delay allocating cpumask for AMU FIE support can be merged independently. Additionally, this series depends on [6] Relevant discussions: [1] https://lore.kernel.org/all/20240229162520.970986-1-vanshikonda@os.amperecomputing.com/ [2] https://lore.kernel.org/all/7eozim2xnepacnnkzxlbx34hib4otycnbn4dqymfziqou5lw5u@5xzpv3t7sxo3/ [3] https://lore.kernel.org/all/20231212072617.14756-1-lihuisong@huawei.com/ [4] https://lore.kernel.org/lkml/ZIHpd6unkOtYVEqP@e120325.cambridge.arm.com/T/#m4e74cb5a0aaa353c60fedc6cfb95ab7a6e381e3c [5] https://lore.kernel.org/all/20240603081331.3829278-1-beata.michalska@arm.com/ [6] https://lore.kernel.org/all/20240827154818.1195849-1-ionela.voinescu@arm.com/ v8: - Drop introducing new function and reuse arch_freq_get_on_cpu, guarding its use in scaling_cur_freq sysfs handler with dedicated config for x86 v7: - Dropping 'arch_topology: init capacity_freq_ref to 0' patch from the series as this one has been sent separately as an independent change [https://lore.kernel.org/all/20240827154818.1195849-1-ionela.voinescu@arm.com/] - Including in the series change that introduces new sysfs entry [PATCH 1/4] - Consequently modifying previously arch_freq_get_on_cpu to match reqs for new sysfs attribute - Dropping an idea of considering a CPU that has been idle for a while as a valid source of information for obtaining an AMU-counter based frequency - Some minor cosmetic changes v6: - delay allocating cpumask for AMU FIE support instead of invalidating the mask upon failure to register cpufreq policy notifications - drop the change to cpufreq core (for cpuinfo_cur_freq) as this one will be sent as a separate change v5: - Fix invalid access to cpumask - Reworked finding reference cpu when getting the freq v4: - dropping seqcount - fixing identifying active cpu within given policy - skipping full dynticks cpus when retrieving the freq - bringing back plugging in arch_freq_get_on_cpu into cpuinfo_cur_freq v3: - dropping changes to cpufreq_verify_current_freq - pulling in changes from Ionela initializing capacity_freq_ref to 0 (thanks for that!) and applying suggestions made by her during last review: - switching to arch_scale_freq_capacity and arch_scale_freq_ref when reversing freq scale factor computation - swapping shift with multiplication - adding time limit for considering last scale update as valid - updating frequency scale factor upon entering idle v2: - Splitting the patches - Adding comment for full dyntick mode - Plugging arch_freq_get_on_cpu into cpufreq_verify_current_freq instead of in show_cpuinfo_cur_freq to allow the framework to stay more in sync with potential freq changes CC: Jonathan Corbet CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: H. Peter Anvin CC: Phil Auld CC: x86@kernel.org CC: linux-doc@vger.kernel.org Beata Michalska (4): cpufreq: Introduce an optional cpuinfo_avg_freq sysfs entry arm64: amu: Delay allocating cpumask for AMU FIE support arm64: Provide an AMU-based version of arch_freq_get_on_cpu arm64: Update AMU-based freq scale factor on entering idle Documentation/admin-guide/pm/cpufreq.rst | 16 ++- arch/arm64/kernel/topology.c | 144 +++++++++++++++++++---- arch/x86/kernel/cpu/aperfmperf.c | 2 +- arch/x86/kernel/cpu/proc.c | 7 +- drivers/cpufreq/Kconfig.x86 | 12 ++ drivers/cpufreq/cpufreq.c | 36 +++++- include/linux/cpufreq.h | 2 +- 7 files changed, 188 insertions(+), 31 deletions(-)