【内核调度、负载计算】【WALT】【walt_update_task_ravg】

最新推荐文章于 2025-04-09 14:45:31 发布

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最新推荐文章于 2025-04-09 14:45:31 发布 · 1.7k 阅读

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walt_update_task_ravg在scheduler_tick中进行更新，即会周期性的更新

walt_update_task_ravg

/* Reflect task activity on its demand and cpu's busy time statistics */
void walt_update_task_ravg(struct task_struct *p, struct rq *rq,
	     int event, u64 wallclock, u64 irqtime)
{
	u64 old_window_start;

	if (walt_disabled || !rq->window_start)
		return;

	lockdep_assert_held(&rq->lock);

	old_window_start = update_window_start(rq, wallclock);

	if (!p->ravg.mark_start)
		goto done;

	update_task_demand(p, rq, event, wallclock);
	update_cpu_busy_time(p, rq, event, wallclock, irqtime);

done:
	if (rq->window_start > old_window_start) {
		unsigned long cap_orig = capacity_orig_of(cpu_of(rq));
		unsigned int busy_limit =
			(walt_ravg_window * walt_busy_threshold) / 100;

		// walt_ravg_window  12ms
        // walt_busy_threshold 75 繁忙的阈值
		busy_limit = (busy_limit * cap_orig) >> SCHED_CAPACITY_SHIFT;
		if (rq->prev_runnable_sum >= busy_limit) {
			if (