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author | Deepthi Dharwar <deepthi@linux.vnet.ibm.com> | 2011-10-28 16:20:42 +0530 |
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committer | Len Brown <len.brown@intel.com> | 2011-11-06 21:13:58 -0500 |
commit | 46bcfad7a819bd17ac4e831b04405152d59784ab (patch) | |
tree | 20041e788154d103edff2699f88d4a30320e3ee2 /drivers/cpuidle/governors | |
parent | 4202735e8ab6ecfb0381631a0d0b58fefe0bd4e2 (diff) | |
download | linux-3.10-46bcfad7a819bd17ac4e831b04405152d59784ab.tar.gz linux-3.10-46bcfad7a819bd17ac4e831b04405152d59784ab.tar.bz2 linux-3.10-46bcfad7a819bd17ac4e831b04405152d59784ab.zip |
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 <deepthi@linux.vnet.ibm.com>
Signed-off-by: Trinabh Gupta <g.trinabh@gmail.com>
Tested-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'drivers/cpuidle/governors')
-rw-r--r-- | drivers/cpuidle/governors/ladder.c | 28 | ||||
-rw-r--r-- | drivers/cpuidle/governors/menu.c | 20 |
2 files changed, 29 insertions, 19 deletions
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); 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