From patchwork Wed Dec 28 21:24:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 637770 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6558C4708E for ; Wed, 28 Dec 2022 21:27:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231327AbiL1V1W (ORCPT ); Wed, 28 Dec 2022 16:27:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230398AbiL1V1V (ORCPT ); Wed, 28 Dec 2022 16:27:21 -0500 Received: from cloudserver094114.home.pl (cloudserver094114.home.pl [79.96.170.134]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9C82140B7; Wed, 28 Dec 2022 13:27:19 -0800 (PST) Received: from localhost (127.0.0.1) (HELO v370.home.net.pl) by /usr/run/smtp (/usr/run/postfix/private/idea_relay_lmtp) via UNIX with SMTP (IdeaSmtpServer 5.1.0) id 0f873d5bd6ca1cb6; Wed, 28 Dec 2022 22:27:18 +0100 Received: from kreacher.localnet (89-77-51-84.dynamic.chello.pl [89.77.51.84]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by v370.home.net.pl (Postfix) with ESMTPSA id 7C12F780AF8; Wed, 28 Dec 2022 22:27:17 +0100 (CET) Authentication-Results: v370.home.net.pl; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: v370.home.net.pl; spf=fail smtp.mailfrom=rjwysocki.net From: "Rafael J. Wysocki" To: Linux PM Cc: Pratyush Yadav , LKML , Linux ACPI , Srinivas Pandruvada Subject: [PATCH v2 2/3] ACPI: processor: perflib: Avoid updating frequency QoS unnecessarily Date: Wed, 28 Dec 2022 22:24:10 +0100 Message-ID: <4798709.31r3eYUQgx@kreacher> In-Reply-To: <12138067.O9o76ZdvQC@kreacher> References: <12138067.O9o76ZdvQC@kreacher> MIME-Version: 1.0 X-CLIENT-IP: 89.77.51.84 X-CLIENT-HOSTNAME: 89-77-51-84.dynamic.chello.pl X-VADE-SPAMSTATE: clean X-VADE-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvhedriedvgdduhedtucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecujffqoffgrffnpdggtffipffknecuuegrihhlohhuthemucduhedtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkfgjfhgggfgtsehtufertddttdejnecuhfhrohhmpedftfgrfhgrvghlucflrdcuhgihshhotghkihdfuceorhhjfiesrhhjfiihshhotghkihdrnhgvtheqnecuggftrfgrthhtvghrnhepvdffueeitdfgvddtudegueejtdffteetgeefkeffvdeftddttdeuhfegfedvjefhnecukfhppeekledrjeejrdehuddrkeegnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehinhgvthepkeelrdejjedrhedurdekgedphhgvlhhopehkrhgvrggthhgvrhdrlhhotggrlhhnvghtpdhmrghilhhfrhhomhepfdftrghfrggvlhculfdrucghhihsohgtkhhifdcuoehrjhifsehrjhifhihsohgtkhhirdhnvghtqedpnhgspghrtghpthhtohephedprhgtphhtthhopehlihhnuhigqdhpmhesvhhgvghrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehpthihrggurghvsegrmhgriihonhdruggvpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtoheplhhinhhugidqrggtphhisehvghgvrhdrkhgvrhhnvghlrdhorhhgpdhrtghpthhtohepshhrihhnihhvrghs rdhprghnughruhhvrggurgeslhhinhhugidrihhnthgvlhdrtghomh X-DCC--Metrics: v370.home.net.pl 1024; Body=5 Fuz1=5 Fuz2=5 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki Modify acpi_processor_get_platform_limit() to avoid updating its frequency QoS request when the _PPC return value has not changed by comparing that value to the previous _PPC return value stored in the performance_platform_limit field of the struct acpi_processor corresponding to the given CPU. While at it, do the _PPC return value check against the state count earlier to avoid setting performance_platform_limit to an invalid value. Signed-off-by: Rafael J. Wysocki --- v1 -> v2: * New patch. * Contains some changes from the previous [1/2] and a change to reset performance_platform_limit on QoS request creation. --- drivers/acpi/processor_perflib.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) Index: linux-pm/drivers/acpi/processor_perflib.c =================================================================== --- linux-pm.orig/drivers/acpi/processor_perflib.c +++ linux-pm/drivers/acpi/processor_perflib.c @@ -76,13 +76,16 @@ static int acpi_processor_get_platform_l index = ppc; + if (pr->performance_platform_limit == index || + ppc >= pr->performance->state_count) + return 0; + pr_debug("CPU %d: _PPC is %d - frequency %s limited\n", pr->id, index, index ? "is" : "is not"); pr->performance_platform_limit = index; - if (ppc >= pr->performance->state_count || - unlikely(!freq_qos_request_active(&pr->perflib_req))) + if (unlikely(!freq_qos_request_active(&pr->perflib_req))) return 0; /* @@ -178,6 +181,13 @@ void acpi_processor_ppc_init(struct cpuf if (!pr) continue; + /* + * Reset performance_platform_limit in case there is a stale + * value in it, so as to make it match the "no limit" QoS value + * below. + */ + pr->performance_platform_limit = 0; + ret = freq_qos_add_request(&policy->constraints, &pr->perflib_req, FREQ_QOS_MAX, INT_MAX);