From 46bcfad7a819bd17ac4e831b04405152d59784ab Mon Sep 17 00:00:00 2001 From: Deepthi Dharwar Date: Fri, 28 Oct 2011 16:20:42 +0530 Subject: cpuidle: Single/Global registration of idle states This patch makes the cpuidle_states structure global (single copy) instead of per-cpu. The statistics needed on per-cpu basis by the governor are kept per-cpu. This simplifies the cpuidle subsystem as state registration is done by single cpu only. Having single copy of cpuidle_states saves memory. Rare case of asymmetric C-states can be handled within the cpuidle driver and architectures such as POWER do not have asymmetric C-states. Having single/global registration of all the idle states, dynamic C-state transitions on x86 are handled by the boot cpu. Here, the boot cpu would disable all the devices, re-populate the states and later enable all the devices, irrespective of the cpu that would receive the notification first. Reference: https://lkml.org/lkml/2011/4/25/83 Signed-off-by: Deepthi Dharwar Signed-off-by: Trinabh Gupta Tested-by: Jean Pihet Reviewed-by: Kevin Hilman Acked-by: Arjan van de Ven Acked-by: Kevin Hilman Signed-off-by: Len Brown --- drivers/cpuidle/governors/ladder.c | 28 +++++++++++++++++----------- drivers/cpuidle/governors/menu.c | 20 ++++++++++++-------- 2 files changed, 29 insertions(+), 19 deletions(-) (limited to 'drivers/cpuidle/governors') diff --git a/drivers/cpuidle/governors/ladder.c b/drivers/cpuidle/governors/ladder.c index 6a686a76711..ef6b9e4727a 100644 --- a/drivers/cpuidle/governors/ladder.c +++ b/drivers/cpuidle/governors/ladder.c @@ -60,9 +60,11 @@ static inline void ladder_do_selection(struct ladder_device *ldev, /** * ladder_select_state - selects the next state to enter + * @drv: cpuidle driver * @dev: the CPU */ -static int ladder_select_state(struct cpuidle_device *dev) +static int ladder_select_state(struct cpuidle_driver *drv, + struct cpuidle_device *dev) { struct ladder_device *ldev = &__get_cpu_var(ladder_devices); struct ladder_device_state *last_state; @@ -77,15 +79,17 @@ static int ladder_select_state(struct cpuidle_device *dev) last_state = &ldev->states[last_idx]; - if (dev->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) - last_residency = cpuidle_get_last_residency(dev) - dev->states[last_idx].exit_latency; + if (drv->states[last_idx].flags & CPUIDLE_FLAG_TIME_VALID) { + last_residency = cpuidle_get_last_residency(dev) - \ + drv->states[last_idx].exit_latency; + } else last_residency = last_state->threshold.promotion_time + 1; /* consider promotion */ - if (last_idx < dev->state_count - 1 && + if (last_idx < drv->state_count - 1 && last_residency > last_state->threshold.promotion_time && - dev->states[last_idx + 1].exit_latency <= latency_req) { + drv->states[last_idx + 1].exit_latency <= latency_req) { last_state->stats.promotion_count++; last_state->stats.demotion_count = 0; if (last_state->stats.promotion_count >= last_state->threshold.promotion_count) { @@ -96,11 +100,11 @@ static int ladder_select_state(struct cpuidle_device *dev) /* consider demotion */ if (last_idx > CPUIDLE_DRIVER_STATE_START && - dev->states[last_idx].exit_latency > latency_req) { + drv->states[last_idx].exit_latency > latency_req) { int i; for (i = last_idx - 1; i > CPUIDLE_DRIVER_STATE_START; i--) { - if (dev->states[i].exit_latency <= latency_req) + if (drv->states[i].exit_latency <= latency_req) break; } ladder_do_selection(ldev, last_idx, i); @@ -123,9 +127,11 @@ static int ladder_select_state(struct cpuidle_device *dev) /** * ladder_enable_device - setup for the governor + * @drv: cpuidle driver * @dev: the CPU */ -static int ladder_enable_device(struct cpuidle_device *dev) +static int ladder_enable_device(struct cpuidle_driver *drv, + struct cpuidle_device *dev) { int i; struct ladder_device *ldev = &per_cpu(ladder_devices, dev->cpu); @@ -134,8 +140,8 @@ static int ladder_enable_device(struct cpuidle_device *dev) ldev->last_state_idx = CPUIDLE_DRIVER_STATE_START; - for (i = 0; i < dev->state_count; i++) { - state = &dev->states[i]; + for (i = 0; i < drv->state_count; i++) { + state = &drv->states[i]; lstate = &ldev->states[i]; lstate->stats.promotion_count = 0; @@ -144,7 +150,7 @@ static int ladder_enable_device(struct cpuidle_device *dev) lstate->threshold.promotion_count = PROMOTION_COUNT; lstate->threshold.demotion_count = DEMOTION_COUNT; - if (i < dev->state_count - 1) + if (i < drv->state_count - 1) lstate->threshold.promotion_time = state->exit_latency; if (i > 0) lstate->threshold.demotion_time = state->exit_latency; diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c index af724e823c8..bcbe8814213 100644 --- a/drivers/cpuidle/governors/menu.c +++ b/drivers/cpuidle/governors/menu.c @@ -182,7 +182,7 @@ static inline int performance_multiplier(void) static DEFINE_PER_CPU(struct menu_device, menu_devices); -static void menu_update(struct cpuidle_device *dev); +static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev); /* This implements DIV_ROUND_CLOSEST but avoids 64 bit division */ static u64 div_round64(u64 dividend, u32 divisor) @@ -228,9 +228,10 @@ static void detect_repeating_patterns(struct menu_device *data) /** * menu_select - selects the next idle state to enter + * @drv: cpuidle driver containing state data * @dev: the CPU */ -static int menu_select(struct cpuidle_device *dev) +static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct menu_device *data = &__get_cpu_var(menu_devices); int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY); @@ -240,7 +241,7 @@ static int menu_select(struct cpuidle_device *dev) struct timespec t; if (data->needs_update) { - menu_update(dev); + menu_update(drv, dev); data->needs_update = 0; } @@ -285,8 +286,8 @@ static int menu_select(struct cpuidle_device *dev) * 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]; + for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) { + struct cpuidle_state *s = &drv->states[i]; if (s->target_residency > data->predicted_us) continue; @@ -323,14 +324,15 @@ static void menu_reflect(struct cpuidle_device *dev, int index) /** * menu_update - attempts to guess what happened after entry + * @drv: cpuidle driver containing state data * @dev: the CPU */ -static void menu_update(struct cpuidle_device *dev) +static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev) { struct menu_device *data = &__get_cpu_var(menu_devices); int last_idx = data->last_state_idx; unsigned int last_idle_us = cpuidle_get_last_residency(dev); - struct cpuidle_state *target = &dev->states[last_idx]; + struct cpuidle_state *target = &drv->states[last_idx]; unsigned int measured_us; u64 new_factor; @@ -384,9 +386,11 @@ static void menu_update(struct cpuidle_device *dev) /** * menu_enable_device - scans a CPU's states and does setup + * @drv: cpuidle driver * @dev: the CPU */ -static int menu_enable_device(struct cpuidle_device *dev) +static int menu_enable_device(struct cpuidle_driver *drv, + struct cpuidle_device *dev) { struct menu_device *data = &per_cpu(menu_devices, dev->cpu); -- cgit v1.2.3