Function test_empty_dequeue

dpdk/app/test/test_pmd_ring_perf.c:32–55

Get cycle counts for dequeuing from an empty ring. Should be 2 or 3 cycles */

/* Get cycle counts for dequeuing from an empty ring. Should be 2 or 3 cycles */
static void
test_empty_dequeue(void)
{
	const unsigned iter_shift = 26;
	const unsigned iterations = 1 << iter_shift;
	unsigned i = 0;
	void *burst[MAX_BURST];

	const uint64_t sc_start = rte_rdtsc();
	for (i = 0; i < iterations; i++)
		rte_ring_sc_dequeue_bulk(r, burst, bulk_sizes[0], NULL);
	const uint64_t sc_end = rte_rdtsc();

	const uint64_t eth_start = rte_rdtsc();
	for (i = 0; i < iterations; i++)
		rte_eth_rx_burst(ring_ethdev_port, 0, (void *)burst,
				bulk_sizes[0]);
	const uint64_t eth_end = rte_rdtsc();

	printf("Ring empty dequeue  : %.1F\n",
			(double)(sc_end - sc_start) / iterations);
	printf("Ethdev empty dequeue: %.1F\n",
			(double)(eth_end - eth_start) / iterations);
}

/*
 * Test function that determines how long an enqueue + dequeue of a single item