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Merge branch 'pm-cpuidle' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into sched/core 

Pull scheduling related CPU idle updates from Rafael J. Wysocki.

Conflicts:
	kernel/sched/idle.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
5bit-waveforms
Ingo Molnar 2014-05-22 10:37:06 +02:00
parent 65c2ce7004 a6220fc19a
commit ec6e7f4082
5 changed files with 59 additions and 35 deletions
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55
drivers/cpuidle/cpuidle.c
View File

@ -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.
*
* Return 0 on success, otherwise:
* -NODEV : the cpuidle framework is not available
* -EBUSY : the cpuidle framework is not initialized
* 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).
*
* 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);
}

17
drivers/cpuidle/governors/menu.c
View File

@ -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))
@ -310,13 +310,6 @@ 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.
@ -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;
}

7
include/linux/cpuidle.h
View File

@ -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

2
kernel/power/suspend.c
View File

@ -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)

13
kernel/sched/idle.c
View File

@ -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