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Merge branch 'pm-cpuidle'

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* pm-cpuidle:
  cpuidle: menu: Avoid pointless checks in menu_select()
  sched / idle: Drop default_idle_call() fallback from call_cpuidle()
  cpuidle: Don't enable all governors by default
  cpuidle: Default to ladder governor on ticking systems
  time: nohz: Expose tick_nohz_enabled
  cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0
This commit is contained in:
Rafael J. Wysocki 2016-01-21 00:43:21 +01:00
commit f11aef69b2
7 changed files with 28 additions and 22 deletions
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2
drivers/cpuidle/Kconfig
View File

@ -19,11 +19,9 @@ config CPU_IDLE_MULTIPLE_DRIVERS
config CPU_IDLE_GOV_LADDER
bool "Ladder governor (for periodic timer tick)"
default y
config CPU_IDLE_GOV_MENU
bool "Menu governor (for tickless system)"
default y
config DT_IDLE_STATES
bool

6
drivers/cpuidle/cpuidle.c
View File

@ -79,9 +79,9 @@ static int find_deepest_state(struct cpuidle_driver *drv,
bool freeze)
{
unsigned int latency_req = 0;
int i, ret = -ENXIO;
int i, ret = 0;
for (i = 0; i < drv->state_count; i++) {
for (i = 1; i < drv->state_count; i++) {
struct cpuidle_state *s = &drv->states[i];
struct cpuidle_state_usage *su = &dev->states_usage[i];
@ -243,7 +243,7 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
* @drv: the cpuidle driver
* @dev: the cpuidle device
*
* Returns the index of the idle state.
* Returns the index of the idle state. The return value must not be negative.
*/
int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
{

9
drivers/cpuidle/governors/ladder.c
View File

@ -17,6 +17,7 @@
#include <linux/pm_qos.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/tick.h>
#include <asm/io.h>
#include <asm/uaccess.h>
@ -184,6 +185,14 @@ static struct cpuidle_governor ladder_governor = {
*/
static int __init init_ladder(void)
{
/*
* When NO_HZ is disabled, or when booting with nohz=off, the ladder
* governor is better so give it a higher rating than the menu
* governor.
*/
if (!tick_nohz_enabled)
ladder_governor.rating = 25;
return cpuidle_register_governor(&ladder_governor);
}

9
drivers/cpuidle/governors/menu.c
View File

@ -294,8 +294,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
data->needs_update = 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))
return 0;
@ -326,6 +324,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
if (latency_req > interactivity_req)
latency_req = interactivity_req;
if (CPUIDLE_DRIVER_STATE_START > 0) {
data->last_state_idx = CPUIDLE_DRIVER_STATE_START - 1;
/*
* We want to default to C1 (hlt), not to busy polling
* unless the timer is happening really really soon.
@ -334,12 +334,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
!drv->states[CPUIDLE_DRIVER_STATE_START].disabled &&
dev->states_usage[CPUIDLE_DRIVER_STATE_START].disable == 0)
data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
} else {
data->last_state_idx = CPUIDLE_DRIVER_STATE_START;
}
/*
* Find the idle state with the lowest power while satisfying
* our constraints.
*/
for (i = CPUIDLE_DRIVER_STATE_START; i < drv->state_count; i++) {
for (i = data->last_state_idx + 1; i < drv->state_count; i++) {
struct cpuidle_state *s = &drv->states[i];
struct cpuidle_state_usage *su = &dev->states_usage[i];

2
include/linux/tick.h
View File

@ -98,6 +98,7 @@ static inline void tick_broadcast_exit(void)
}
#ifdef CONFIG_NO_HZ_COMMON
extern int tick_nohz_enabled;
extern int tick_nohz_tick_stopped(void);
extern void tick_nohz_idle_enter(void);
extern void tick_nohz_idle_exit(void);
@ -106,6 +107,7 @@ extern ktime_t tick_nohz_get_sleep_length(void);
extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
extern u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time);
#else /* !CONFIG_NO_HZ_COMMON */
#define tick_nohz_enabled (0)
static inline int tick_nohz_tick_stopped(void) { return 0; }
static inline void tick_nohz_idle_enter(void) { }
static inline void tick_nohz_idle_exit(void) { }

6
kernel/sched/idle.c
View File

@ -97,12 +97,6 @@ void default_idle_call(void)
static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
int next_state)
{
/* Fall back to the default arch idle method on errors. */
if (next_state < 0) {
default_idle_call();
return next_state;
}
/*
* The idle task must be scheduled, it is pointless to go to idle, just
* update no idle residency and return.

2
kernel/time/tick-sched.c
View File

@ -387,7 +387,7 @@ void __init tick_nohz_init(void)
/*
* NO HZ enabled ?
*/
static int tick_nohz_enabled __read_mostly = 1;
int tick_nohz_enabled __read_mostly = 1;
unsigned long tick_nohz_active __read_mostly;
/*
* Enable / Disable tickless mode