ceph/src/seastar/dpdk/test/test/test_cycles.c

   1 /*-
   2  *   BSD LICENSE
   3  *
   4  *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
   5  *   All rights reserved.
   6  *
   7  *   Redistribution and use in source and binary forms, with or without
   8  *   modification, are permitted provided that the following conditions
   9  *   are met:
  10  *
  11  *     * Redistributions of source code must retain the above copyright
  12  *       notice, this list of conditions and the following disclaimer.
  13  *     * Redistributions in binary form must reproduce the above copyright
  14  *       notice, this list of conditions and the following disclaimer in
  15  *       the documentation and/or other materials provided with the
  16  *       distribution.
  17  *     * Neither the name of Intel Corporation nor the names of its
  18  *       contributors may be used to endorse or promote products derived
  19  *       from this software without specific prior written permission.
  20  *
  21  *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  24  *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  25  *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  28  *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  29  *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30  *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdint.h>
  36
  37 #include <rte_common.h>
  38 #include <rte_cycles.h>
  39
  40 #include "test.h"
  41
  42 #define N 10000
  43
  44 /*
  45  * Cycles test
  46  * ===========
  47  *
  48  * - Loop N times and check that the timer always increments and
  49  *   never decrements during this loop.
  50  *
  51  * - Wait one second using rte_usleep() and check that the increment
  52  *   of cycles is correct with regard to the frequency of the timer.
  53  */
  54
  55 static int
  56 test_cycles(void)
  57 {
  58         unsigned i;
  59         uint64_t start_cycles, cycles, prev_cycles;
  60         uint64_t hz = rte_get_timer_hz();
  61         uint64_t max_inc = (hz / 100); /* 10 ms max between 2 reads */
  62
  63         /* check that the timer is always incrementing */
  64         start_cycles = rte_get_timer_cycles();
  65         prev_cycles = start_cycles;
  66         for (i=0; i<N; i++) {
  67                 cycles = rte_get_timer_cycles();
  68                 if ((uint64_t)(cycles - prev_cycles) > max_inc) {
  69                         printf("increment too high or going backwards\n");
  70                         return -1;
  71                 }
  72                 prev_cycles = cycles;
  73         }
  74
  75         /* check that waiting 1 second is precise */
  76         prev_cycles = rte_get_timer_cycles();
  77         rte_delay_us(1000000);
  78         cycles = rte_get_timer_cycles();
  79
  80         if ((uint64_t)(cycles - prev_cycles) > (hz + max_inc)) {
  81                 printf("delay_us is not accurate: too long\n");
  82                 return -1;
  83         }
  84         if ((uint64_t)(cycles - prev_cycles) < (hz - max_inc)) {
  85                 printf("delay_us is not accurate: too short\n");
  86                 return -1;
  87         }
  88
  89         return 0;
  90 }
  91
  92 REGISTER_TEST_COMMAND(cycles_autotest, test_cycles);
  93
  94 /*
  95  * rte_delay_us_callback test
  96  *
  97  * - check if callback is correctly registered/unregistered
  98  *
  99  */
 100
 101 static unsigned int pattern;
 102 static void my_rte_delay_us(unsigned int us)
 103 {
 104         pattern += us;
 105 }
 106
 107 static int
 108 test_user_delay_us(void)
 109 {
 110         pattern = 0;
 111
 112         rte_delay_us(2);
 113         if (pattern != 0)
 114                 return -1;
 115
 116         /* register custom delay function */
 117         rte_delay_us_callback_register(my_rte_delay_us);
 118
 119         rte_delay_us(2);
 120         if (pattern != 2)
 121                 return -1;
 122
 123         rte_delay_us(3);
 124         if (pattern != 5)
 125                 return -1;
 126
 127         /* restore original delay function */
 128         rte_delay_us_callback_register(rte_delay_us_block);
 129
 130         rte_delay_us(3);
 131         if (pattern != 5)
 132                 return -1;
 133
 134         return 0;
 135 }
 136
 137 REGISTER_TEST_COMMAND(user_delay_us, test_user_delay_us);