Function power_timer_cb

dpdk/examples/l3fwd-power/main.c:427–467

Frequency scale down timer callback */

/*  Frequency scale down timer callback */
static void
power_timer_cb(__rte_unused struct rte_timer *tim,
			  __rte_unused void *arg)
{
	uint64_t hz;
	float sleep_time_ratio;
	unsigned lcore_id = rte_lcore_id();

	/* accumulate total execution time in us when callback is invoked */
	sleep_time_ratio = (float)(stats[lcore_id].sleep_time) /
					(float)SCALING_PERIOD;
	/**
	 * check whether need to scale down frequency a step if it sleep a lot.
	 */
	if (sleep_time_ratio >= SCALING_DOWN_TIME_RATIO_THRESHOLD) {
		if (rte_power_freq_down)
			rte_power_freq_down(lcore_id);
	}
	else if ( (unsigned)(stats[lcore_id].nb_rx_processed /
		stats[lcore_id].nb_iteration_looped) < MAX_PKT_BURST) {
		/**
		 * scale down a step if average packet per iteration less
		 * than expectation.
		 */
		if (rte_power_freq_down)
			rte_power_freq_down(lcore_id);
	}

	/**
	 * initialize another timer according to current frequency to ensure
	 * timer interval is relatively fixed.
	 */
	hz = rte_get_timer_hz();
	rte_timer_reset(&power_timers[lcore_id], hz/TIMER_NUMBER_PER_SECOND,
				SINGLE, lcore_id, power_timer_cb, NULL);

	stats[lcore_id].nb_rx_processed = 0;
	stats[lcore_id].nb_iteration_looped = 0;

	stats[lcore_id].sleep_time = 0;
}

/* Enqueue a single packet, and send burst if queue is filled */
static inline int