*
* Started by: Thomas Gleixner and Ingo Molnar
*
- * For licencing details see kernel-base/COPYING
+ * Distribute under GPLv2.
*/
#include <linux/cpu.h>
#include <linux/err.h>
if (!ts->tick_stopped)
return;
+ touch_softlockup_watchdog();
+
cpu_clear(cpu, nohz_cpu_mask);
now = ktime_get();
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
*
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);
/*
}
}
- 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);
next_jiffies = get_next_timer_interrupt(last_jiffies);
delta_jiffies = next_jiffies - last_jiffies;
+ rt_jiffies = rt_needs_cpu(cpu);
+ if (rt_jiffies && rt_jiffies < delta_jiffies)
+ delta_jiffies = rt_jiffies;
+
if (rcu_needs_cpu(cpu))
delta_jiffies = 1;
/*
/* Check, if the timer was already in the past */
if (hrtimer_active(&ts->sched_timer))
goto out;
- } else if(!tick_program_event(expires, 0))
+ } else if (!tick_program_event(expires, 0))
goto out;
/*
* We are past the event already. So we crossed a
}
/**
- * nohz_restart_sched_tick - restart the idle tick from the idle task
+ * tick_nohz_restart_sched_tick - restart the idle tick from the idle task
*
* Restart the idle tick when the CPU is woken up from idle
*/
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
*/
#ifdef CONFIG_HIGH_RES_TIMERS
/*
- * We rearm the timer until we get disabled by the idle code
+ * We rearm the timer until we get disabled by the idle code.
* Called with interrupts disabled and timer->base->cpu_base->lock held.
*/
static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
{
struct tick_sched *ts =
container_of(timer, struct tick_sched, sched_timer);
- struct hrtimer_cpu_base *base = timer->base->cpu_base;
struct pt_regs *regs = get_irq_regs();
ktime_t now = ktime_get();
int cpu = smp_processor_id();
touch_softlockup_watchdog();
ts->idle_jiffies++;
}
- /*
- * update_process_times() might take tasklist_lock, hence
- * drop the base lock. sched-tick hrtimers are per-CPU and
- * never accessible by userspace APIs, so this is safe to do.
- */
- spin_unlock(&base->lock);
update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING);
- spin_lock(&base->lock);
}
/* Do not restart, when we are in the idle loop */
/* Get the next period (per cpu) */
ts->sched_timer.expires = tick_init_jiffy_update();
offset = ktime_to_ns(tick_period) >> 1;
- do_div(offset, NR_CPUS);
+ do_div(offset, num_possible_cpus());
offset *= smp_processor_id();
ts->sched_timer.expires = ktime_add_ns(ts->sched_timer.expires, offset);