scheduler_tick()

 

/*
 * This function gets called by the timer code, with HZ frequency.
 * We call it with interrupts disabled.
 *
 * It also gets called by the fork code, when changing the parent's
 * timeslices.
 */
void scheduler_tick(void)
{
    int cpu = smp_processor_id();
    struct rq *rq = cpu_rq(cpu);
    struct task_struct *curr = rq->curr;

    sched_clock_tick();

    raw_spin_lock(&rq->lock);
    update_rq_clock(rq);
    update_cpu_load(rq);
    curr->sched_class->task_tick(rq, curr, 0);
    raw_spin_unlock(&rq->lock);

    perf_event_task_tick(curr);

#ifdef CONFIG_SMP
    rq->idle_at_tick = idle_cpu(cpu);
    trigger_load_balance(rq, cpu);
#endif
}