From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AF96717744 for ; Wed, 9 Aug 2023 11:31:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34B4DC433C7; Wed, 9 Aug 2023 11:31:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580681; bh=neC51Y0PDL9Aw9f6ud1M8ut0384NXKPeGvxiEUROiD8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EJSAyVqP7C6NcBrOQcA8PUWsF/6UH4SWR7EOpBGKOjvNigK5mBeFwr69INKzwzOqV CKX209QVpId4xZoQ8oZwHLKukuS5uSzWA5yYt8JIipv6qAju0E3eCGCw3xkFpHs+4A Yzjz1DG1M7aVUcWU+xHnbw8uhH7IbayO82PsHmEU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Hagar Hemdan Subject: [PATCH 5.4 082/154] ACPI: processor: perflib: Avoid updating frequency QoS unnecessarily Date: Wed, 9 Aug 2023 12:41:53 +0200 Message-ID: <20230809103639.705410704@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103636.887175326@linuxfoundation.org> References: <20230809103636.887175326@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Rafael J. Wysocki commit 99387b016022c29234c4ebf9abd34358c6e56532 upstream. 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, and make acpi_processor_ppc_init() use FREQ_QOS_MAX_DEFAULT_VALUE as the "no limit" frequency QoS for consistency. Signed-off-by: Rafael J. Wysocki Tested-by: Hagar Hemdan Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/processor_perflib.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -79,13 +79,16 @@ 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; /* @@ -180,9 +183,16 @@ 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); + &pr->perflib_req, FREQ_QOS_MAX, + FREQ_QOS_MAX_DEFAULT_VALUE); if (ret < 0) pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu, ret);