void sys_tick_handler(void)
{
uint32_t next_timer = 0;
volatile uint32_t reload = systick_get_reload();
uint32_t this_timeslice;
SysTick_Hook();
jiffies+= clock_interval;
_n_int++;
next_timer = ktimers_check();
#ifdef CONFIG_LOWPOWER
if (next_timer < 0 || next_timer > 1000){
next_timer = 1000; /* Wake up every second if timer is too long, or if no timers */
}
/* Checking deep sleep */
if (next_timer >= 1000 && scheduler_can_sleep()) {
systick_interrupt_disable();
cputimer_start(next_timer);
return;
}
#ifdef CONFIG_TICKLESS
this_timeslice = task_timeslice();
if (_sched_active && (this_timeslice == 0) && (!task_running())) {
schedule();
} else {
systick_interrupt_disable();
cputimer_start(this_timeslice);
}
return;
#endif
#endif
if (_sched_active && ((task_timeslice() == 0) || (!task_running()))) {
schedule();
(void)next_timer;
}
}
static
int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
struct sched_domain *sd, enum cpu_idle_type idle,
int *all_pinned)
{
int tsk_cache_hot = 0;
/*
* We do not migrate tasks that are:
* 1) running (obviously), or
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) are cache-hot on their current CPU.
*/
if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) {
schedstat_inc(p, se.nr_failed_migrations_affine);
return 0;
}
*all_pinned = 0;
if (task_running(rq, p)) {
schedstat_inc(p, se.nr_failed_migrations_running);
return 0;
}
/*
* Aggressive migration if:
* 1) task is cache cold, or
* 2) too many balance attempts have failed.
*/
tsk_cache_hot = task_hot(p, rq->clock, sd);
if (!tsk_cache_hot ||
sd->nr_balance_failed > sd->cache_nice_tries) {
#ifdef CONFIG_SCHEDSTATS
if (tsk_cache_hot) {
schedstat_inc(sd, lb_hot_gained[idle]);
schedstat_inc(p, se.nr_forced_migrations);
}
#endif
return 1;
}
if (tsk_cache_hot) {
schedstat_inc(p, se.nr_failed_migrations_hot);
return 0;
}
return 1;
}
