From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jacob Pan Subject: [PATCH v2 2/3] cpuidle: allow setting deepest idle Date: Mon, 14 Nov 2016 10:47:57 -0800 Message-ID: <1479149278-12418-3-git-send-email-jacob.jun.pan@linux.intel.com> References: <1479149278-12418-1-git-send-email-jacob.jun.pan@linux.intel.com> Return-path: Received: from mga02.intel.com ([134.134.136.20]:42184 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933880AbcKNSt4 (ORCPT ); Mon, 14 Nov 2016 13:49:56 -0500 In-Reply-To: <1479149278-12418-1-git-send-email-jacob.jun.pan@linux.intel.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Peter Zijlstra , Ingo Molnar , Thomas Gleixner , LKML , Linux PM Cc: Arjan van de Ven , Srinivas Pandruvada , Len Brown , Rafael Wysocki , Eduardo Valentin , Zhang Rui , Petr Mladek , Sebastian Andrzej Siewior , Jacob Pan When idle injection is used to cap power, we need to override governor's choice of idle states. This patch allows caller to select the deepest idle state on a CPU therefore achieve the maximum potential power saving. Signed-off-by: Jacob Pan --- drivers/cpuidle/cpuidle.c | 11 +++++++++++ include/linux/cpuidle.h | 4 +++- kernel/sched/idle.c | 3 +++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index c73207a..887a52a 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -97,6 +97,17 @@ static int find_deepest_state(struct cpuidle_driver *drv, return ret; } +/* Set the current cpu to use the deepest idle state, override governors */ +void cpuidle_use_deepest_state(bool enable) +{ + struct cpuidle_device *dev; + + preempt_disable(); + dev = cpuidle_get_device(); + dev->use_deepest_state = enable; + preempt_enable(); +} + #ifdef CONFIG_SUSPEND /** * cpuidle_find_deepest_state - Find the deepest available idle state. diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index bb31373..7f93c63 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -74,6 +74,7 @@ struct cpuidle_state { struct cpuidle_device { unsigned int registered:1; unsigned int enabled:1; + unsigned int use_deepest_state:1; unsigned int cpu; int last_residency; @@ -192,11 +193,12 @@ static inline struct cpuidle_driver *cpuidle_get_cpu_driver( static inline struct cpuidle_device *cpuidle_get_device(void) {return NULL; } #endif -#if defined(CONFIG_CPU_IDLE) && defined(CONFIG_SUSPEND) +#if defined(CONFIG_CPU_IDLE) extern int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev); extern int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev); +extern void cpuidle_use_deepest_state(bool enable); #else static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, struct cpuidle_device *dev) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index cb6442f..9e80f32 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -173,6 +173,9 @@ static void cpuidle_idle_call(void) next_state = cpuidle_find_deepest_state(drv, dev); call_cpuidle(drv, dev, next_state); + } else if (dev->use_deepest_state) { + next_state = cpuidle_find_deepest_state(drv, dev); + call_cpuidle(drv, dev, next_state); } else { /* * Ask the cpuidle framework to choose a convenient idle state. -- 1.9.1