From patchwork Fri Jan 31 16:24:39 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beata Michalska X-Patchwork-Id: 861176 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0CECB1F0E2C; Fri, 31 Jan 2025 16:25:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738340712; cv=none; b=cvG8LKhBNRgtBgDpL9uaGbNMu2KOgCG+1n8d8EQWIRLLPYfYxsZ/FaOand78nbeCrUWt+gtNNp52fen3UgYoDNDJNIqKNbDKOjDUcBfz8s8YNQ5DagxPSMok+Dlf2GZmaE08NpxSR6YmBNSooEjitbe6+3/2GVLhBwb715Z9vn4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738340712; c=relaxed/simple; bh=UrPeDcBjCasShll16HrywUAszFC33HX30upT7GhLdsc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HiLx76q4VFpaOh6XOwtsDRyRxfej3tOQ+bADNd194ShdN8krdwA8G3xsgSsH2OdCfF7zmPSac+xBJzpEYTPZyA63BljFF7J3C4E4m1CdAG0RsHOubifmNjYBrFHSKCBCxiG4lMqf+7ubF1iOC3G/p3HOopW8t87y+XysI5y1B7w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 C221DFEC; Fri, 31 Jan 2025 08:25:34 -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 4656F3F694; Fri, 31 Jan 2025 08:25:07 -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, ptsm@linux.microsoft.com Subject: [PATCH v10 4/4] arm64: Update AMU-based freq scale factor on entering idle Date: Fri, 31 Jan 2025 16:24:39 +0000 Message-Id: <20250131162439.3843071-5-beata.michalska@arm.com> In-Reply-To: <20250131162439.3843071-1-beata.michalska@arm.com> References: <20250131162439.3843071-1-beata.michalska@arm.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Now that the frequency scale factor has been activated for retrieving current frequency on a given CPU, trigger its update upon entering idle. This will, to an extent, allow querying last known frequency in a non-invasive way. It will also improve the frequency scale factor accuracy when a CPU entering idle did not receive a tick for a while. As a consequence, for idle cores, the reported frequency will be the last one observed before entering the idle state. Suggested-by: Vanshidhar Konda Signed-off-by: Beata Michalska Reviewed-by: Prasanna Kumar T S M Reviewed-by: Sumit Gupta --- arch/arm64/kernel/topology.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index bd238e5c2133..6f0cab8e746b 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -213,6 +213,19 @@ static __always_inline bool amu_fie_cpu_supported(unsigned int cpu) cpumask_test_cpu(cpu, amu_fie_cpus); } +void arch_cpu_idle_enter(void) +{ + unsigned int cpu = smp_processor_id(); + + if (!amu_fie_cpu_supported(cpu)) + return; + + /* Kick in AMU update but only if one has not happened already */ + if (housekeeping_cpu(cpu, HK_TYPE_TICK) && + time_is_before_jiffies(per_cpu(cpu_amu_samples.last_scale_update, cpu))) + amu_scale_freq_tick(); +} + #define AMU_SAMPLE_EXP_MS 20 int arch_freq_get_on_cpu(int cpu)