diff options
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 31 | ||||
| -rw-r--r-- | drivers/cpuidle/governors/menu.c | 23 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 4 |
3 files changed, 51 insertions, 7 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index dbefe15bd58..a5071084337 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -74,6 +74,17 @@ static void cpuidle_idle_call(void) */ hrtimer_peek_ahead_timers(); #endif + + /* + * Call the device's prepare function before calling the + * governor's select function. ->prepare gives the device's + * cpuidle driver a chance to update any dynamic information + * of its cpuidle states for the current idle period, e.g. + * state availability, latencies, residencies, etc. + */ + if (dev->prepare) + dev->prepare(dev); + /* ask the governor for the next state */ next_state = cpuidle_curr_governor->select(dev); if (need_resched()) { @@ -282,6 +293,26 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) poll_idle_init(dev); + /* + * cpuidle driver should set the dev->power_specified bit + * before registering the device if the driver provides + * power_usage numbers. + * + * For those devices whose ->power_specified is not set, + * we fill in power_usage with decreasing values as the + * cpuidle code has an implicit assumption that state Cn + * uses less power than C(n-1). + * + * With CONFIG_ARCH_HAS_CPU_RELAX, C0 is already assigned + * an power value of -1. So we use -2, -3, etc, for other + * c-states. + */ + if (!dev->power_specified) { + int i; + for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++) + dev->states[i].power_usage = -1 - i; + } + per_cpu(cpuidle_devices, dev->cpu) = dev; list_add(&dev->device_list, &cpuidle_detected_devices); if ((ret = cpuidle_add_sysfs(sys_dev))) { diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index 1b128702d30..c2408bbe9c2 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -234,6 +234,7 @@ static int menu_select(struct cpuidle_device *dev) { struct menu_device *data = &__get_cpu_var(menu_devices); int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY); + unsigned int power_usage = -1; int i; int multiplier; @@ -278,19 +279,27 @@ static int menu_select(struct cpuidle_device *dev) if (data->expected_us > 5) data->last_state_idx = CPUIDLE_DRIVER_STATE_START; - - /* find the deepest idle state that satisfies our constraints */ + /* + * Find the idle state with the lowest power while satisfying + * our constraints. + */ for (i = CPUIDLE_DRIVER_STATE_START; i < dev->state_count; i++) { struct cpuidle_state *s = &dev->states[i]; + if (s->flags & CPUIDLE_FLAG_IGNORE) + continue; if (s->target_residency > data->predicted_us) - break; + continue; if (s->exit_latency > latency_req) - break; + continue; if (s->exit_latency * multiplier > data->predicted_us) - break; - data->exit_us = s->exit_latency; - data->last_state_idx = i; + continue; + + if (s->power_usage < power_usage) { + power_usage = s->power_usage; + data->last_state_idx = i; + data->exit_us = s->exit_latency; + } } return data->last_state_idx; diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 55215cce500..36ca9721a0c 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -52,6 +52,7 @@ struct cpuidle_state { #define CPUIDLE_FLAG_SHALLOW (0x20) /* low latency, minimal savings */ #define CPUIDLE_FLAG_BALANCED (0x40) /* medium latency, moderate savings */ #define CPUIDLE_FLAG_DEEP (0x80) /* high latency, large savings */ +#define CPUIDLE_FLAG_IGNORE (0x100) /* ignore during this idle period */ #define CPUIDLE_DRIVER_FLAGS_MASK (0xFFFF0000) @@ -84,6 +85,7 @@ struct cpuidle_state_kobj { struct cpuidle_device { unsigned int registered:1; unsigned int enabled:1; + unsigned int power_specified:1; unsigned int cpu; int last_residency; @@ -97,6 +99,8 @@ struct cpuidle_device { struct completion kobj_unregister; void *governor_data; struct cpuidle_state *safe_state; + + int (*prepare) (struct cpuidle_device *dev); }; DECLARE_PER_CPU(struct cpuidle_device *, cpuidle_devices); |