From patchwork Fri Apr 5 13:33:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beata Michalska X-Patchwork-Id: 13619068 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 E0224CD1297 for ; Fri, 5 Apr 2024 13:34:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-Id:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=vDK50boq5gc9ByEiwAfc57R2xkKMHa/Fs8r9x3EykYo=; b=Yb5y8l9rnqikSt y2cSRkhvTxUq/QSrx6UsM/iRDpb+I+B623zcTdQaXYzrV7UyumlaORvc6kKSHFO7gLy/FZkul+Vqh C+tpmGj0QQ7Sk6806eCNtKuniFFsRV09xZWxcAbsIjVMoYb6aTac+Qq7NcEtVuNCEh+cCnxSqIQHe /gzKTEtwcwyOSFve+yFl8mu/ubf5oL/e0Ej1ZkfGTIPVqC8+x2WHoXGPjzbC6AnOc3ZOltNXW3Qar aWZTUyohAvnviCYyUB+uZc8q/WEZ/iSKsE4t1Dq2Qo2B7+shKVPno2ehX4VEWLYVCqGO3rW4of+V8 7tSCbVooH92ewK0nN6Qg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rsjhV-00000007Ey7-3CKf; Fri, 05 Apr 2024 13:33:49 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rsjhS-00000007Etc-2efq for linux-arm-kernel@lists.infradead.org; Fri, 05 Apr 2024 13:33:48 +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 312F0DA7; Fri, 5 Apr 2024 06:34:10 -0700 (PDT) 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 20A2A3F7B4; Fri, 5 Apr 2024 06:33:38 -0700 (PDT) From: Beata Michalska To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ionela.voinescu@arm.com, vanshikonda@os.amperecomputing.com Cc: sudeep.holla@arm.com, will@kernel.org, catalin.marinas@arm.com, vincent.guittot@linaro.org, sumitg@nvidia.com, yang@os.amperecomputing.com, lihuisong@huawei.com Subject: [PATCH v4 0/4] Add support for AArch64 AMUv1-based arch_freq_get_on_cpu Date: Fri, 5 Apr 2024 14:33:15 +0100 Message-Id: <20240405133319.859813-1-beata.michalska@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240405_063346_721898_87FAB6C5 X-CRM114-Status: GOOD ( 12.05 ) 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 Introducing arm64 specific version of arch_freq_get_on_cpu, cashing on existing implementation for FIE and AMUv1 support: the frequency scale factor, updated on each sched tick, serves as a base for retrieving the frequency for a given CPU, representing an average frequency reported between the ticks - thus its accuracy is limited. The changes have been rather lightly (due to some limitations) tested on an FVP model. Note that some small discrepancies have been observed while testing (on the model) and this is currently being investigated, though it should not have any significant impact on the overall results. 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 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 Beata Michalska (3): arm64: Provide an AMU-based version of arch_freq_get_on_cpu arm64: Update AMU-based frequency scale factor on entering idle cpufreq: Use arch specific feedback for cpuinfo_cur_freq Ionela Voinescu (1): arch_topology: init capacity_freq_ref to 0 arch/arm64/kernel/topology.c | 125 ++++++++++++++++++++++++++++++++--- drivers/base/arch_topology.c | 8 ++- drivers/cpufreq/cpufreq.c | 4 +- 3 files changed, 123 insertions(+), 14 deletions(-)