diff options
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 55 | ||||
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 17 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 7 | ||||
| -rw-r--r-- | kernel/power/suspend.c | 2 | ||||
| -rw-r--r-- | kernel/sched/idle.c | 13 |
5 files changed, 59 insertions, 35 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 8236746e46bb..cb7019977c50 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -32,6 +32,7 @@ LIST_HEAD(cpuidle_detected_devices); static int enabled_devices; static int off __read_mostly; static int initialized __read_mostly; +static bool use_deepest_state __read_mostly; int cpuidle_disabled(void) { @@ -65,23 +66,42 @@ int cpuidle_play_dead(void) } /** - * cpuidle_enabled - check if the cpuidle framework is ready - * @dev: cpuidle device for this cpu - * @drv: cpuidle driver for this cpu + * cpuidle_use_deepest_state - Enable/disable the "deepest idle" mode. + * @enable: Whether enable or disable the feature. + * + * If the "deepest idle" mode is enabled, cpuidle will ignore the governor and + * always use the state with the greatest exit latency (out of the states that + * are not disabled). * - * Return 0 on success, otherwise: - * -NODEV : the cpuidle framework is not available - * -EBUSY : the cpuidle framework is not initialized + * This function can only be called after cpuidle_pause() to avoid races. */ -int cpuidle_enabled(struct cpuidle_driver *drv, struct cpuidle_device *dev) +void cpuidle_use_deepest_state(bool enable) { - if (off || !initialized) - return -ENODEV; + use_deepest_state = enable; +} - if (!drv || !dev || !dev->enabled) - return -EBUSY; +/** + * cpuidle_find_deepest_state - Find the state of the greatest exit latency. + * @drv: cpuidle driver for a given CPU. + * @dev: cpuidle device for a given CPU. + */ +static int cpuidle_find_deepest_state(struct cpuidle_driver *drv, + struct cpuidle_device *dev) +{ + unsigned int latency_req = 0; + int i, ret = CPUIDLE_DRIVER_STATE_START - 1; - return 0; + for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { + struct cpuidle_state *s = &drv->states[i]; + struct cpuidle_state_usage *su = &dev->states_usage[i]; + + if (s->disabled || su->disable || s->exit_latency <= latency_req) + continue; + + latency_req = s->exit_latency; + ret = i; + } + return ret; } /** @@ -138,6 +158,15 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, */ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { + if (off || !initialized) + return -ENODEV; + + if (!drv || !dev || !dev->enabled) + return -EBUSY; + + if (unlikely(use_deepest_state)) + return cpuidle_find_deepest_state(drv, dev); + return cpuidle_curr_governor->select(drv, dev); } @@ -169,7 +198,7 @@ int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, */ void cpuidle_reflect(struct cpuidle_device *dev, int index) { - if (cpuidle_curr_governor->reflect) + if (cpuidle_curr_governor->reflect && !unlikely(use_deepest_state)) cpuidle_curr_governor->reflect(dev, index); } diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 71b523293354..c4f80c15a48d 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -296,7 +296,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->needs_update = 0; } - data->last_state_idx = 0; + data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1; /* Special case when user has set very strict latency requirement */ if (unlikely(latency_req == 0)) @@ -311,13 +311,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) data->bucket = which_bucket(data->next_timer_us); /* - * if the correction factor is 0 (eg first time init or cpu hotplug - * etc), we actually want to start out with a unity factor. - */ - if (data->correction_factor[data->bucket] == 0) - data->correction_factor[data->bucket] = RESOLUTION * DECAY; - - /* * Force the result of multiplication to be 64 bits even if both * operands are 32 bits. * Make sure to round up for half microseconds. @@ -466,9 +459,17 @@ static int menu_enable_device(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct menu_device *data = &per_cpu(menu_devices, dev->cpu); + int i; memset(data, 0, sizeof(struct menu_device)); + /* + * if the correction factor is 0 (eg first time init or cpu hotplug + * etc), we actually want to start out with a unity factor. + */ + for(i = 0; i < BUCKETS; i++) + data->correction_factor[i] = RESOLUTION * DECAY; + return 0; } diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index b0238cba440b..c51a436135c4 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -120,8 +120,6 @@ struct cpuidle_driver { #ifdef CONFIG_CPU_IDLE extern void disable_cpuidle(void); -extern int cpuidle_enabled(struct cpuidle_driver *drv, - struct cpuidle_device *dev); extern int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev); extern int cpuidle_enter(struct cpuidle_driver *drv, @@ -145,13 +143,11 @@ extern void cpuidle_resume(void); extern int cpuidle_enable_device(struct cpuidle_device *dev); extern void cpuidle_disable_device(struct cpuidle_device *dev); extern int cpuidle_play_dead(void); +extern void cpuidle_use_deepest_state(bool enable); extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device *dev); #else static inline void disable_cpuidle(void) { } -static inline int cpuidle_enabled(struct cpuidle_driver *drv, - struct cpuidle_device *dev) -{return -ENODEV; } static inline int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) {return -ENODEV; } @@ -180,6 +176,7 @@ static inline int cpuidle_enable_device(struct cpuidle_device *dev) {return -ENODEV; } static inline void cpuidle_disable_device(struct cpuidle_device *dev) { } static inline int cpuidle_play_dead(void) {return -ENODEV; } +static inline void cpuidle_use_deepest_state(bool enable) {} static inline struct cpuidle_driver *cpuidle_get_cpu_driver( struct cpuidle_device *dev) {return NULL; } #endif diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index 8233cd4047d7..155721f7f909 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -54,9 +54,11 @@ static void freeze_begin(void) static void freeze_enter(void) { + cpuidle_use_deepest_state(true); cpuidle_resume(); wait_event(suspend_freeze_wait_head, suspend_freeze_wake); cpuidle_pause(); + cpuidle_use_deepest_state(false); } void freeze_wake(void) diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 34083c9ac976..25b9423abce9 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -98,10 +98,11 @@ static void cpuidle_idle_call(void) rcu_idle_enter(); /* - * Check if the cpuidle framework is ready, otherwise fallback - * to the default arch specific idle method + * Ask the cpuidle framework to choose a convenient idle state. + * Fall back to the default arch idle method on errors. */ - if (cpuidle_enabled(drv, dev)) { + next_state = cpuidle_select(drv, dev); + if (next_state < 0) { use_default: /* * We can't use the cpuidle framework, let's use the default @@ -115,12 +116,6 @@ use_default: goto exit_idle; } - /* - * Ask the governor to choose an idle state it thinks - * it is convenient to go to. There is *always* a - * convenient idle state - */ - next_state = cpuidle_select(drv, dev); /* * The idle task must be scheduled, it is pointless to |