diff options
| -rw-r--r-- | include/linux/tick.h | 6 | ||||
| -rw-r--r-- | kernel/softirq.c | 7 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 70 |
3 files changed, 60 insertions, 23 deletions
diff --git a/include/linux/tick.h b/include/linux/tick.h index f4a1395e05f..0fadf95debe 100644 --- a/include/linux/tick.h +++ b/include/linux/tick.h @@ -51,8 +51,10 @@ struct tick_sched { unsigned long idle_jiffies; unsigned long idle_calls; unsigned long idle_sleeps; + int idle_active; ktime_t idle_entrytime; ktime_t idle_sleeptime; + ktime_t idle_lastupdate; ktime_t sleep_length; unsigned long last_jiffies; unsigned long next_jiffies; @@ -103,6 +105,8 @@ extern void tick_nohz_stop_sched_tick(void); extern void tick_nohz_restart_sched_tick(void); extern void tick_nohz_update_jiffies(void); extern ktime_t tick_nohz_get_sleep_length(void); +extern void tick_nohz_stop_idle(int cpu); +extern u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time); # else static inline void tick_nohz_stop_sched_tick(void) { } static inline void tick_nohz_restart_sched_tick(void) { } @@ -113,6 +117,8 @@ static inline ktime_t tick_nohz_get_sleep_length(void) return len; } +static inline void tick_nohz_stop_idle(int cpu) { } +static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return 0; } # endif /* !NO_HZ */ #endif diff --git a/kernel/softirq.c b/kernel/softirq.c index 8fe1ff40102..d7837d45419 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -280,9 +280,14 @@ asmlinkage void do_softirq(void) */ void irq_enter(void) { +#ifdef CONFIG_NO_HZ + int cpu = smp_processor_id(); + if (idle_cpu(cpu) && !in_interrupt()) + tick_nohz_stop_idle(cpu); +#endif __irq_enter(); #ifdef CONFIG_NO_HZ - if (idle_cpu(smp_processor_id())) + if (idle_cpu(cpu)) tick_nohz_update_jiffies(); #endif } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 49e12f6a4ba..63f24b55069 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -143,6 +143,44 @@ void tick_nohz_update_jiffies(void) local_irq_restore(flags); } +void tick_nohz_stop_idle(int cpu) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + + if (ts->idle_active) { + ktime_t now, delta; + now = ktime_get(); + delta = ktime_sub(now, ts->idle_entrytime); + ts->idle_lastupdate = now; + ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + ts->idle_active = 0; + } +} + +static ktime_t tick_nohz_start_idle(int cpu) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t now, delta; + + now = ktime_get(); + if (ts->idle_active) { + delta = ktime_sub(now, ts->idle_entrytime); + ts->idle_lastupdate = now; + ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + } + ts->idle_entrytime = now; + ts->idle_active = 1; + return now; +} + +u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) +{ + struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + + *last_update_time = ktime_to_us(ts->idle_lastupdate); + return ktime_to_us(ts->idle_sleeptime); +} + /** * tick_nohz_stop_sched_tick - stop the idle tick from the idle task * @@ -155,13 +193,14 @@ void tick_nohz_stop_sched_tick(void) unsigned long seq, last_jiffies, next_jiffies, delta_jiffies, flags; unsigned long rt_jiffies; struct tick_sched *ts; - ktime_t last_update, expires, now, delta; + ktime_t last_update, expires, now; struct clock_event_device *dev = __get_cpu_var(tick_cpu_device).evtdev; int cpu; local_irq_save(flags); cpu = smp_processor_id(); + now = tick_nohz_start_idle(cpu); ts = &per_cpu(tick_cpu_sched, cpu); /* @@ -193,19 +232,7 @@ void tick_nohz_stop_sched_tick(void) } } - now = ktime_get(); - /* - * When called from irq_exit we need to account the idle sleep time - * correctly. - */ - if (ts->tick_stopped) { - delta = ktime_sub(now, ts->idle_entrytime); - ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); - } - - ts->idle_entrytime = now; ts->idle_calls++; - /* Read jiffies and the time when jiffies were updated last */ do { seq = read_seqbegin(&xtime_lock); @@ -337,23 +364,22 @@ void tick_nohz_restart_sched_tick(void) int cpu = smp_processor_id(); struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); unsigned long ticks; - ktime_t now, delta; + ktime_t now; - if (!ts->tick_stopped) + local_irq_disable(); + tick_nohz_stop_idle(cpu); + + if (!ts->tick_stopped) { + local_irq_enable(); return; + } /* Update jiffies first */ - now = ktime_get(); - - local_irq_disable(); select_nohz_load_balancer(0); + now = ktime_get(); tick_do_update_jiffies64(now); cpu_clear(cpu, nohz_cpu_mask); - /* Account the idle time */ - delta = ktime_sub(now, ts->idle_entrytime); - ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); - /* * We stopped the tick in idle. Update process times would miss the * time we slept as update_process_times does only a 1 tick |