From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63778C04EBF for ; Wed, 5 Dec 2018 22:45:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CC2320879 for ; Wed, 5 Dec 2018 22:45:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CC2320879 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=rjwysocki.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728629AbeLEWpu (ORCPT ); Wed, 5 Dec 2018 17:45:50 -0500 Received: from cloudserver094114.home.pl ([79.96.170.134]:56347 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727177AbeLEWpt (ORCPT ); Wed, 5 Dec 2018 17:45:49 -0500 Received: from 79.184.252.87.ipv4.supernova.orange.pl (79.184.252.87) (HELO aspire.rjw.lan) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.177) id bb70f2fd3131f3ff; Wed, 5 Dec 2018 23:45:46 +0100 From: "Rafael J. Wysocki" To: Linux PM Cc: LKML , Linux Documentation , Peter Zijlstra , Daniel Lezcano , Giovanni Gherdovich , Doug Smythies Subject: [PATCH] cpuidle: Add cpuidle.governor= command line parameter Date: Wed, 05 Dec 2018 23:45:34 +0100 Message-ID: <1752296.bicKxrytZO@aspire.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki Add cpuidle.governor= command line parameter to allow the default cpuidle governor to be replaced. That is useful, for example, if someone running a tickful kernel wants to use the menu governor on it. Signed-off-by: Rafael J. Wysocki --- On top of https://patchwork.kernel.org/patch/10714995/ and https://patchwork.kernel.org/patch/10705317/ --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ Documentation/admin-guide/pm/cpuidle.rst | 7 +++++++ drivers/cpuidle/cpuidle.c | 1 + drivers/cpuidle/cpuidle.h | 1 + drivers/cpuidle/governor.c | 9 +++++++-- 5 files changed, 19 insertions(+), 2 deletions(-) Index: linux-pm/drivers/cpuidle/governor.c =================================================================== --- linux-pm.orig/drivers/cpuidle/governor.c +++ linux-pm/drivers/cpuidle/governor.c @@ -11,10 +11,13 @@ #include #include #include +#include #include #include "cpuidle.h" +char param_governor[CPUIDLE_NAME_LEN]; + LIST_HEAD(cpuidle_governors); struct cpuidle_governor *cpuidle_curr_governor; @@ -86,9 +89,11 @@ int cpuidle_register_governor(struct cpu mutex_lock(&cpuidle_lock); if (__cpuidle_find_governor(gov->name) == NULL) { ret = 0; - list_add_tail(&gov->governor_list, &cpuidle_governors); if (!cpuidle_curr_governor || - cpuidle_curr_governor->rating < gov->rating) + !strncasecmp(param_governor, gov->name, CPUIDLE_NAME_LEN) || + (cpuidle_curr_governor->rating < gov->rating && + strncasecmp(param_governor, cpuidle_curr_governor->name, + CPUIDLE_NAME_LEN))) cpuidle_switch_governor(gov); } mutex_unlock(&cpuidle_lock); Index: linux-pm/drivers/cpuidle/cpuidle.c =================================================================== --- linux-pm.orig/drivers/cpuidle/cpuidle.c +++ linux-pm/drivers/cpuidle/cpuidle.c @@ -731,4 +731,5 @@ static int __init cpuidle_init(void) } module_param(off, int, 0444); +module_param_string(governor, param_governor, CPUIDLE_NAME_LEN, 0444); core_initcall(cpuidle_init); Index: linux-pm/drivers/cpuidle/cpuidle.h =================================================================== --- linux-pm.orig/drivers/cpuidle/cpuidle.h +++ linux-pm/drivers/cpuidle/cpuidle.h @@ -7,6 +7,7 @@ #define __DRIVER_CPUIDLE_H /* For internal use only */ +extern char param_governor[]; extern struct cpuidle_governor *cpuidle_curr_governor; extern struct list_head cpuidle_governors; extern struct list_head cpuidle_detected_devices; Index: linux-pm/Documentation/admin-guide/pm/cpuidle.rst =================================================================== --- linux-pm.orig/Documentation/admin-guide/pm/cpuidle.rst +++ linux-pm/Documentation/admin-guide/pm/cpuidle.rst @@ -576,6 +576,13 @@ processors implementing the architecture however, so it is rather crude and not very energy-efficient. For this reason, it is not recommended for production use. +The ``cpuidle.governor=`` kernel command line switch allows the ``CPUIdle`` +governor to use to be specified. It has to be appended with a string matching +the name of an available governor (e.g. ``cpuidle.governor=menu``) and that +governor will be used instead of the default one. It is possible to force +the ``menu`` governor to be used on the systems that use the ``ladder`` governor +by default this way, for example. + The other kernel command line parameters controlling CPU idle time management described below are only relevant for the *x86* architecture and some of them affect Intel processors only. Index: linux-pm/Documentation/admin-guide/kernel-parameters.txt =================================================================== --- linux-pm.orig/Documentation/admin-guide/kernel-parameters.txt +++ linux-pm/Documentation/admin-guide/kernel-parameters.txt @@ -674,6 +674,9 @@ cpuidle.off=1 [CPU_IDLE] disable the cpuidle sub-system + cpuidle.governor= + [CPU_IDLE] Name of the cpuidle governor to use. + cpufreq.off=1 [CPU_FREQ] disable the cpufreq sub-system