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-rw-r--r--drivers/cpuidle/governors/menu.c27
-rw-r--r--include/linux/tick.h7
-rw-r--r--kernel/time/tick-sched.c12
3 files changed, 35 insertions, 11 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index f53a929bd2bd..267982e471e0 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -295,6 +295,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
unsigned int expected_interval;
unsigned long nr_iowaiters, cpu_load;
int resume_latency = dev_pm_qos_raw_read_value(device);
+ ktime_t delta_next;
if (data->needs_update) {
menu_update(drv, dev);
@@ -312,7 +313,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
}
/* determine the expected residency time, round up */
- data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length());
+ data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next));
get_iowait_load(&nr_iowaiters, &cpu_load);
data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
@@ -396,9 +397,31 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
* expected idle duration is shorter than the tick period length.
*/
if ((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) ||
- expected_interval < TICK_USEC)
+ expected_interval < TICK_USEC) {
+ unsigned int delta_next_us = ktime_to_us(delta_next);
+
*stop_tick = false;
+ if (!tick_nohz_tick_stopped() && idx > 0 &&
+ drv->states[idx].target_residency > delta_next_us) {
+ /*
+ * The tick is not going to be stopped and the target
+ * residency of the state to be returned is not within
+ * the time until the next timer event including the
+ * tick, so try to correct that.
+ */
+ for (i = idx - 1; i >= 0; i--) {
+ if (drv->states[i].disabled ||
+ dev->states_usage[i].disable)
+ continue;
+
+ idx = i;
+ if (drv->states[i].target_residency <= delta_next_us)
+ break;
+ }
+ }
+ }
+
data->last_state_idx = idx;
return data->last_state_idx;
diff --git a/include/linux/tick.h b/include/linux/tick.h
index e8e7ff16b929..55388ab45fd4 100644
--- a/include/linux/tick.h
+++ b/include/linux/tick.h
@@ -122,7 +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_sleep_length(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);
extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time);
@@ -146,9 +146,10 @@ 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_sleep_length(void)
+static inline ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
{
- return NSEC_PER_SEC / HZ;
+ *delta_next = TICK_NSEC;
+ return *delta_next;
}
static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index c57c98c7e953..edb9d49b4996 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1023,10 +1023,11 @@ bool tick_nohz_idle_got_tick(void)
/**
* 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
*
* Called from power state control code with interrupts disabled
*/
-ktime_t tick_nohz_get_sleep_length(void)
+ktime_t tick_nohz_get_sleep_length(ktime_t *delta_next)
{
struct clock_event_device *dev = __this_cpu_read(tick_cpu_device.evtdev);
struct tick_sched *ts = this_cpu_ptr(&tick_cpu_sched);
@@ -1040,12 +1041,14 @@ ktime_t tick_nohz_get_sleep_length(void)
WARN_ON_ONCE(!ts->inidle);
+ *delta_next = ktime_sub(dev->next_event, now);
+
if (!can_stop_idle_tick(cpu, ts))
- goto out_dev;
+ return *delta_next;
next_event = tick_nohz_next_event(ts, cpu);
if (!next_event)
- goto out_dev;
+ return *delta_next;
/*
* If the next highres timer to expire is earlier than next_event, the
@@ -1055,9 +1058,6 @@ ktime_t tick_nohz_get_sleep_length(void)
hrtimer_next_event_without(&ts->sched_timer));
return ktime_sub(next_event, now);
-
-out_dev:
- return ktime_sub(dev->next_event, now);
}
/**