From patchwork Wed Apr 17 09:38:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Beata Michalska X-Patchwork-Id: 13633114 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 6830EC001CC for ; Wed, 17 Apr 2024 09:39:24 +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:References:In-Reply-To: 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: List-Owner; bh=t2Jg1CAAXRjRXQZHTNTAuK8YRF6VxXO2VxgyDHOetsg=; b=14b867kXo3vXoR WhKNgS/k19pt+/w7W7bt1o/hVE5AsuxpCK01f2CzJcsPERfrAoTmbYpXdiN+/k1xxq8YSPN7PE8sJ uMfIqv3o26ZQTD0gad0/sT4itxbCePsNCVbMm1rnInOMlU1H8zjkoxWgCgy4LFSSYbnEuh4i9A618 7sxCzJtPCfpCAQr6m0/2XwCWNHlLTTs+bR3VBpugGMAxNFXVOHYiHIIB7SS7akLj8TbDhuO7XchaG 00z2xCK5w8YVvv8Vh5K0eOO4lpyeLfkQQHB+hu+NHg2JSJhMNF9AvcmGzTvyZNkdgrs6mfBMi9Y8W A1deH4F1DAuNnsdefyqQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rx1l5-0000000FRlm-2cu8; Wed, 17 Apr 2024 09:39:15 +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 1rx1kz-0000000FRj1-15dX for linux-arm-kernel@lists.infradead.org; Wed, 17 Apr 2024 09:39:10 +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 55EA7DA7; Wed, 17 Apr 2024 02:39:36 -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 A741E3F64C; Wed, 17 Apr 2024 02:39:06 -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, viresh.kumar@linaro.org Subject: [PATCH v5 4/5] arm64: Update AMU-based frequency scale factor on entering idle Date: Wed, 17 Apr 2024 10:38:47 +0100 Message-Id: <20240417093848.1555462-5-beata.michalska@arm.com> In-Reply-To: <20240417093848.1555462-1-beata.michalska@arm.com> References: <20240417093848.1555462-1-beata.michalska@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240417_023909_447618_00E61B6F X-CRM114-Status: GOOD ( 11.99 ) 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 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 --- arch/arm64/kernel/topology.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index 475fdbf3032a..3110863ee18c 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_update, cpu))) + amu_scale_freq_tick(); +} + #define AMU_SAMPLE_EXP_MS 20 unsigned int arch_freq_get_on_cpu(int cpu) @@ -239,8 +252,8 @@ unsigned int arch_freq_get_on_cpu(int cpu) * this boils down to identifying an active cpu within the same freq * domain, if any. */ - if (!housekeeping_cpu(cpu, HK_TYPE_TICK) || - time_is_before_jiffies(last_update + msecs_to_jiffies(AMU_SAMPLE_EXP_MS))) { + if (!housekeeping_cpu(cpu, HK_TYPE_TICK) || (!idle_cpu(cpu) && + time_is_before_jiffies(last_update + msecs_to_jiffies(AMU_SAMPLE_EXP_MS)))) { struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); int ref_cpu = cpu;