From e5f1b245870d59be0e6cc3b33edf5406a3b59648 Mon Sep 17 00:00:00 2001 From: Daniel Lezcano Date: Wed, 5 Oct 2016 09:33:12 +0200 Subject: cpuidle: governors: Remove remaining old module code The governor's code use try_module_get() and put_module() to refcount the governor's module. But the governors are not compiled as module. The refcount does not prevent to switch the governor or unload a module as they aren't compiled as modules. The code is pointless, so remove it. Signed-off-by: Daniel Lezcano Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index bb31373c3478..15deea449edc 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -235,8 +235,6 @@ struct cpuidle_governor { int (*select) (struct cpuidle_driver *drv, struct cpuidle_device *dev); void (*reflect) (struct cpuidle_device *dev, int index); - - struct module *owner; }; #ifdef CONFIG_CPU_IDLE -- cgit v1.2.3 From bb8313b603eb8fd52de48a079bfcd72dcab2ef1e Mon Sep 17 00:00:00 2001 From: Jacob Pan Date: Mon, 28 Nov 2016 23:03:04 -0800 Subject: cpuidle: Allow enforcing deepest idle state selection When idle injection is used to cap power, we need to override the governor's choice of idle states. For this reason, make it possible the deepest idle state selection to be enforced by setting a flag on a given CPU to achieve the maximum potential power draw reduction. Signed-off-by: Jacob Pan [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki --- include/linux/cpuidle.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 15deea449edc..da346f2817a8 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -74,6 +74,7 @@ struct cpuidle_driver_kobj; 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) +#ifdef 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) @@ -204,6 +206,9 @@ static inline int cpuidle_find_deepest_state(struct cpuidle_driver *drv, static inline int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev) {return -ENODEV; } +static inline void cpuidle_use_deepest_state(bool enable) +{ +} #endif /* kernel/sched/idle.c */ -- cgit v1.2.3 From c1de45ca831acee9b72c9320dde447edafadb43f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 28 Nov 2016 23:03:05 -0800 Subject: sched/idle: Add support for tasks that inject idle Idle injection drivers such as Intel powerclamp and ACPI PAD drivers use realtime tasks to take control of CPU then inject idle. There are two issues with this approach: 1. Low efficiency: injected idle task is treated as busy so sched ticks do not stop during injected idle period, the result of these unwanted wakeups can be ~20% loss in power savings. 2. Idle accounting: injected idle time is presented to user as busy. This patch addresses the issues by introducing a new PF_IDLE flag which allows any given task to be treated as idle task while the flag is set. Therefore, idle injection tasks can run through the normal flow of NOHZ idle enter/exit to get the correct accounting as well as tick stop when possible. The implication is that idle task is then no longer limited to PID == 0. Acked-by: Ingo Molnar Signed-off-by: Peter Zijlstra Signed-off-by: Jacob Pan Signed-off-by: Rafael J. Wysocki --- include/linux/cpu.h | 2 ++ include/linux/sched.h | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/cpu.h b/include/linux/cpu.h index b886dc17f2f3..ac0efae38072 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -245,6 +245,8 @@ void arch_cpu_idle_dead(void); int cpu_report_state(int cpu); int cpu_check_up_prepare(int cpu); void cpu_set_state_online(int cpu); +void play_idle(unsigned long duration_ms); + #ifdef CONFIG_HOTPLUG_CPU bool cpu_wait_death(unsigned int cpu, int seconds); bool cpu_report_death(void); diff --git a/include/linux/sched.h b/include/linux/sched.h index 348f51b0ec92..114c7fcb6af6 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2254,6 +2254,7 @@ extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, /* * Per process flags */ +#define PF_IDLE 0x00000002 /* I am an IDLE thread */ #define PF_EXITING 0x00000004 /* getting shut down */ #define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */ #define PF_VCPU 0x00000010 /* I'm a virtual CPU */ @@ -2609,7 +2610,7 @@ extern struct task_struct *idle_task(int cpu); */ static inline bool is_idle_task(const struct task_struct *p) { - return p->pid == 0; + return !!(p->flags & PF_IDLE); } extern struct task_struct *curr_task(int cpu); extern void ia64_set_curr_task(int cpu, struct task_struct *p); -- cgit v1.2.3