From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 145EC45B42; Tue, 15 Oct 2024 11:30:20 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id D5EA84027C; Tue, 15 Oct 2024 11:30:19 +0200 (CEST) Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) by mails.dpdk.org (Postfix) with ESMTP id 46DBB400D7 for ; Tue, 15 Oct 2024 11:30:18 +0200 (CEST) Received: from mail.maildlp.com (unknown [172.19.88.214]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4XSTHJ0sBpz1HL58; Tue, 15 Oct 2024 17:26:04 +0800 (CST) Received: from kwepemm600004.china.huawei.com (unknown [7.193.23.242]) by mail.maildlp.com (Postfix) with ESMTPS id 4C9841A016C; Tue, 15 Oct 2024 17:30:16 +0800 (CST) Received: from [10.67.121.59] (10.67.121.59) by kwepemm600004.china.huawei.com (7.193.23.242) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 15 Oct 2024 17:30:15 +0800 Message-ID: <79a4e28d-57d7-ad02-8cd2-3bc0e6c49283@huawei.com> Date: Tue, 15 Oct 2024 17:30:15 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v10 0/2] power: introduce PM QoS interface To: Stephen Hemminger CC: , , , , , , , , , References: <20240320105529.5626-1-lihuisong@huawei.com> <20240912023812.30885-1-lihuisong@huawei.com> <20241014082725.325b327e@hermes.local> From: "lihuisong (C)" In-Reply-To: <20241014082725.325b327e@hermes.local> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.67.121.59] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To kwepemm600004.china.huawei.com (7.193.23.242) X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org 在 2024/10/14 23:27, Stephen Hemminger 写道: > On Thu, 12 Sep 2024 10:38:10 +0800 > Huisong Li wrote: > >> The deeper the idle state, the lower the power consumption, but the longer >> the resume time. Some service are delay sensitive and very except the low >> resume time, like interrupt packet receiving mode. >> >> And the "/sys/devices/system/cpu/cpuX/power/pm_qos_resume_latency_us" sysfs >> interface is used to set and get the resume latency limit on the cpuX for >> userspace. Please see the description in kernel document[1]. >> Each cpuidle governor in Linux select which idle state to enter based on >> this CPU resume latency in their idle task. >> >> The per-CPU PM QoS API can be used to control this CPU's idle state >> selection and limit just enter the shallowest idle state to low the delay >> after sleep by setting strict resume latency (zero value). >> >> [1] https://www.kernel.org/doc/html/latest/admin-guide/abi-testing.html?highlight=pm_qos_resume_latency_us#abi-sys-devices-power-pm-qos-resume-latency-us > > This is not a direct critique of this patch. > The power library should have been designed to take a single configuration structure > specifying CPU frequencies, wake up latency, and all the parameters from the kernel. > And there would be a simple API with: rte_power_config_set() and rte_power_config_get(). Agreed. There are several different configuration objects in power library. It would be better if we could put the relevant configurations together. This may be able to do it after Sivaprasad's optimized patches for core and uncore codes in power library. > > .