diff options
| -rw-r--r-- | drivers/cpuidle/cpuidle.c | 19 | ||||
| -rw-r--r-- | include/linux/cpuidle.h | 1 | ||||
| -rw-r--r-- | include/linux/tick.h | 7 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 12 |
4 files changed, 36 insertions, 3 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 7f108309e871..0f4b7c45df3e 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -328,9 +328,23 @@ int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, int index) { + int ret = 0; + + /* + * Store the next hrtimer, which becomes either next tick or the next + * timer event, whatever expires first. Additionally, to make this data + * useful for consumers outside cpuidle, we rely on that the governor's + * ->select() callback have decided, whether to stop the tick or not. + */ + WRITE_ONCE(dev->next_hrtimer, tick_nohz_get_next_hrtimer()); + if (cpuidle_state_is_coupled(drv, index)) - return cpuidle_enter_state_coupled(dev, drv, index); - return cpuidle_enter_state(dev, drv, index); + ret = cpuidle_enter_state_coupled(dev, drv, index); + else + ret = cpuidle_enter_state(dev, drv, index); + + WRITE_ONCE(dev->next_hrtimer, 0); + return ret; } /** @@ -511,6 +525,7 @@ static void __cpuidle_device_init(struct cpuidle_device *dev) { memset(dev->states_usage, 0, sizeof(dev->states_usage)); dev->last_residency = 0; + dev->next_hrtimer = 0; } /** diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h index 3b39472324a3..bb9a0db89f1a 100644 --- a/include/linux/cpuidle.h +++ b/include/linux/cpuidle.h @@ -83,6 +83,7 @@ struct cpuidle_device { unsigned int use_deepest_state:1; unsigned int poll_time_limit:1; unsigned int cpu; + ktime_t next_hrtimer; int last_residency; struct cpuidle_state_usage states_usage[CPUIDLE_STATE_MAX]; diff --git a/include/linux/tick.h b/include/linux/tick.h index 55388ab45fd4..8891b5ac3e40 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -122,6 +122,7 @@ extern void tick_nohz_idle_enter(void); extern void tick_nohz_idle_exit(void); extern void tick_nohz_irq_exit(void); extern bool tick_nohz_idle_got_tick(void); +extern ktime_t tick_nohz_get_next_hrtimer(void); extern ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next); extern unsigned long tick_nohz_get_idle_calls(void); extern unsigned long tick_nohz_get_idle_calls_cpu(int cpu); @@ -145,7 +146,11 @@ static inline void tick_nohz_idle_restart_tick(void) { } static inline void tick_nohz_idle_enter(void) { } static inline void tick_nohz_idle_exit(void) { } static inline bool tick_nohz_idle_got_tick(void) { return false; } - +static inline ktime_t tick_nohz_get_next_hrtimer(void) +{ + /* Next wake up is the tick period, assume it starts now */ + return ktime_add(ktime_get(), TICK_NSEC); +} static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next) { *delta_next = TICK_NSEC; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 6fa52cd6df0b..8d18e03124ff 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1023,6 +1023,18 @@ bool tick_nohz_idle_got_tick(void) } /** + * tick_nohz_get_next_hrtimer - return the next expiration time for the hrtimer + * or the tick, whatever that expires first. Note that, if the tick has been + * stopped, it returns the next hrtimer. + * + * Called from power state control code with interrupts disabled + */ +ktime_t tick_nohz_get_next_hrtimer(void) +{ + return __this_cpu_read(tick_cpu_device.evtdev)->next_event; +} + +/** * tick_nohz_get_sleep_length - return the expected length of the current sleep * @delta_next: duration until the next event if the tick cannot be stopped * |