/**
* tick_nohz_idle_exit - restart the idle tick from the idle task
*
* Restart the idle tick when the CPU is woken up from idle
* This also exit the RCU extended quiescent state. The CPU
* can use RCU again after this function is called.
*/
void tick_nohz_idle_exit(void)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
unsigned long ticks;
#endif
ktime_t now;
local_irq_disable();
WARN_ON_ONCE(!ts->inidle);
ts->inidle = 0;
if (ts->idle_active || ts->tick_stopped)
now = ktime_get();
if (ts->idle_active)
tick_nohz_stop_idle(cpu, now);
if (!ts->tick_stopped) {
local_irq_enable();
return;
}
/* Update jiffies first */
select_nohz_load_balancer(0);
tick_do_update_jiffies64(now);
#ifdef CONFIG_MTK_SCHED_CMP
update_cpu_load_nohz();
#endif
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
/*
* We stopped the tick in idle. Update process times would miss the
* time we slept as update_process_times does only a 1 tick
* accounting. Enforce that this is accounted to idle !
*/
ticks = jiffies - ts->idle_jiffies;
/*
* We might be one off. Do not randomly account a huge number of ticks!
*/
if (ticks && ticks < LONG_MAX)
account_idle_ticks(ticks);
#endif
calc_load_exit_idle();
touch_softlockup_watchdog();
/*
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
ts->idle_exittime = now;
tick_nohz_restart(ts, now);
local_irq_enable();
}
/**
* tick_nohz_update_jiffies - update jiffies when idle was interrupted
*
* Called from interrupt entry when the CPU was idle
*
* In case the sched_tick was stopped on this CPU, we have to check if jiffies
* must be updated. Otherwise an interrupt handler could use a stale jiffy
* value. We do this unconditionally on any cpu, as we don't know whether the
* cpu, which has the update task assigned is in a long sleep.
*/
static void tick_nohz_update_jiffies(ktime_t now)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
unsigned long flags;
ts->idle_waketime = now;
local_irq_save(flags);
tick_do_update_jiffies64(now);
local_irq_restore(flags);
calc_load_exit_idle();
touch_softlockup_watchdog();
}
static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
{
/* Update jiffies first */
tick_do_update_jiffies64(now);
update_cpu_load_nohz();
calc_load_exit_idle();
touch_softlockup_watchdog();
/*
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
ts->idle_exittime = now;
tick_nohz_restart(ts, now);
}
void tick_nohz_idle_exit(void)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
unsigned long ticks;
#endif
ktime_t now;
local_irq_disable();
WARN_ON_ONCE(!ts->inidle);
ts->inidle = 0;
/* Cancel the timer because CPU already waken up from the C-states*/
menu_hrtimer_cancel();
if (ts->idle_active || ts->tick_stopped)
now = ktime_get();
if (ts->idle_active)
tick_nohz_stop_idle(cpu, now);
if (!ts->tick_stopped) {
local_irq_enable();
return;
}
select_nohz_load_balancer(0);
tick_do_update_jiffies64(now);
#ifndef CONFIG_VIRT_CPU_ACCOUNTING
ticks = jiffies - ts->idle_jiffies;
if (ticks && ticks < LONG_MAX)
account_idle_ticks(ticks);
#endif
calc_load_exit_idle();
touch_softlockup_watchdog();
ts->tick_stopped = 0;
ts->idle_exittime = now;
tick_nohz_restart(ts, now);
local_irq_enable();
}
