app/test/test_rand_perf.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2019 Ericsson AB
   3  */
   4
   5 #include <inttypes.h>
   6 #include <stdio.h>
   7
   8 #include <rte_common.h>
   9 #include <rte_cycles.h>
  10 #include <rte_random.h>
  11
  12 #include "test.h"
  13
  14 static volatile uint64_t vsum;
  15
  16 #define ITERATIONS (100000000)
  17
  18 enum rand_type {
  19         rand_type_64
  20 };
  21
  22 static const char *
  23 rand_type_desc(enum rand_type rand_type)
  24 {
  25         switch (rand_type) {
  26         case rand_type_64:
  27                 return "Full 64-bit [rte_rand()]";
  28         default:
  29                 return NULL;
  30         }
  31 }
  32
  33 static __rte_always_inline void
  34 test_rand_perf_type(enum rand_type rand_type)
  35 {
  36         uint64_t start;
  37         uint32_t i;
  38         uint64_t end;
  39         uint64_t sum = 0;
  40         uint64_t op_latency;
  41
  42         start = rte_rdtsc();
  43
  44         for (i = 0; i < ITERATIONS; i++) {
  45                 switch (rand_type) {
  46                 case rand_type_64:
  47                         sum += rte_rand();
  48                         break;
  49                 }
  50         }
  51
  52         end = rte_rdtsc();
  53
  54         /* to avoid an optimizing compiler removing the whole loop */
  55         vsum = sum;
  56
  57         op_latency = (end - start) / ITERATIONS;
  58
  59         printf("%s: %"PRId64" TSC cycles/op\n", rand_type_desc(rand_type),
  60                op_latency);
  61 }
  62
  63 static int
  64 test_rand_perf(void)
  65 {
  66         rte_srand(42);
  67
  68         printf("Pseudo-random number generation latencies:\n");
  69
  70         test_rand_perf_type(rand_type_64);
  71
  72         return 0;
  73 }
  74
  75 REGISTER_TEST_COMMAND(rand_perf_autotest, test_rand_perf);