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: 13955554 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 4DB1DC0218F for ; Fri, 31 Jan 2025 16:31:51 +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:References:In-Reply-To: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:List-Owner; bh=aq4eaUxs6VzHkR8cIYvqvwq0cFMPu8jWCwRKgpRs7BE=; b=Slsw5GCtxAjphIBFlLnT3cikEF jAQsKv6hsWHU6zFDUZ0ct0IbbKwlv3w23sfSr7q95K88spg0/uxeqehpOfQNNYlmPAMqnRfZ3JSRy QnJKnGmBFreSd1cGSgIAgJd57qGFln61EYnhq9CmfC+54H3CG9ve0X0/ToBaKPWNfM9EC0mrCtrU3 yuEOsyu3oRBB/d8L1hjoWz9/L0gBLelDXupJoZkVg9jrTsgHW+3mDL6VEf3an0QN7lTcx+TvMYd1D c6UYZKMoK6MGXWpoUIu3GSN5yfRMb/9NZLYIOGgM5A9oH0bNEKc4u6S0cn6hvMnOmjius8CELD8qJ SiXa/F6g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tdtvf-0000000Az8y-06zF; Fri, 31 Jan 2025 16:31:39 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tdtpN-0000000Ay6F-3W5B for linux-arm-kernel@lists.infradead.org; Fri, 31 Jan 2025 16:25:11 +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 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> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250131_082509_915372_ABC58B70 X-CRM114-Status: UNSURE ( 9.48 ) X-CRM114-Notice: Please train this message. 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 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)