Function rte_pie_enqueue_nonempty

dpdk/lib/sched/rte_pie.h:257–308

* @brief Decides if new packet should be enqueued or dropped for non-empty queue * * @param pie_cfg [in] config pointer to a PIE configuration parameter structure * @param pie [in,out] data pointer to PIE runtime data * @param pkt_len [in] packet length in bytes * @param time [in] current time (measured in cpu cycles) * * @return Operation status * @retval 0 enqueue the packet * @retval 1

 * @retval 2 drop the packet based on mark probability criterion
 */
static inline int
rte_pie_enqueue_nonempty(const struct rte_pie_config *pie_cfg,
	struct rte_pie *pie,
	uint32_t pkt_len,
	const uint64_t time)
{
	/* Check queue space against the tail drop threshold */
	if (pie->qlen >= pie_cfg->tailq_th) {

		pie->accu_prob = 0;
		return 1;
	}

	if (pie->active) {
		/* Update drop probability after certain interval */
		if ((time - pie->last_measurement) >= pie_cfg->dp_update_interval)
			_calc_drop_probability(pie_cfg, pie, time);

		/* Decide whether packet to be dropped or enqueued */
		if (_rte_pie_drop(pie_cfg, pie) && pie->burst_allowance == 0)
			return 2;
	}

	/* When queue occupancy is over a certain threshold, turn on PIE */
	if ((pie->active == 0) &&
		(pie->qlen >= (pie_cfg->tailq_th * 0.1))) {
		pie->active = 1;
		pie->qdelay_old = 0;
		pie->drop_prob = 0;
		pie->in_measurement = 1;
		pie->departed_bytes_count = 0;
		pie->avg_dq_time = 0;
		pie->last_measurement = time;
		pie->burst_allowance = pie_cfg->max_burst;
		pie->accu_prob = 0;
		pie->start_measurement = time;
	}

	/* when queue has been idle for a while, turn off PIE and Reset counters */
	if (pie->active == 1 &&
		pie->qlen < (pie_cfg->tailq_th * 0.1)) {
		pie->active =  0;
		pie->in_measurement = 0;
	}

	/* Update PIE qlen parameter */
	pie->qlen++;
	pie->qlen_bytes += pkt_len;

	/* No drop */
	return 0;
}

/**
 * @brief Decides if new packet should be enqueued or dropped