From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo de Lara Subject: [PATCH v6 02/10] test/hash: improve accuracy on cycle measurements Date: Wed, 10 Jun 2015 16:25:19 +0100 Message-ID: <1433949927-14767-3-git-send-email-pablo.de.lara.guarch@intel.com> References: <1432289771-12799-1-git-send-email-pablo.de.lara.guarch@intel.com> <1433949927-14767-1-git-send-email-pablo.de.lara.guarch@intel.com> To: dev@dpdk.org Return-path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 8DA915A9F for ; Wed, 10 Jun 2015 17:25:30 +0200 (CEST) In-Reply-To: <1433949927-14767-1-git-send-email-pablo.de.lara.guarch@intel.com> List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Cycles per hash calculation were measured per single operation. It is much more accurate to run several iterations between measurements and divide by number of iterations. Signed-off-by: Pablo de Lara --- app/test/test_hash_functions.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/app/test/test_hash_functions.c b/app/test/test_hash_functions.c index 4efb3cd..767b2bc 100644 --- a/app/test/test_hash_functions.c +++ b/app/test/test_hash_functions.c @@ -83,21 +83,21 @@ static void run_hash_func_perf_test(rte_hash_function f, uint32_t init_val, uint32_t key_len) { - static uint8_t key[RTE_HASH_KEY_LENGTH_MAX]; - uint64_t ticks = 0, start, end; + static uint8_t key[HASHTEST_ITERATIONS][RTE_HASH_KEY_LENGTH_MAX]; + uint64_t ticks, start, end; unsigned i, j; for (i = 0; i < HASHTEST_ITERATIONS; i++) { - for (j = 0; j < key_len; j++) - key[j] = (uint8_t) rte_rand(); - - start = rte_rdtsc(); - f(key, key_len, init_val); - end = rte_rdtsc(); - ticks += end - start; + key[i][j] = (uint8_t) rte_rand(); } + start = rte_rdtsc(); + for (i = 0; i < HASHTEST_ITERATIONS; i++) + f(key[i], key_len, init_val); + end = rte_rdtsc(); + ticks = end - start; + printf("%-12s, %-18u, %-13u, %.02f\n", get_hash_name(f), (unsigned) key_len, (unsigned) init_val, (double)ticks / HASHTEST_ITERATIONS); } -- 2.4.2