ceph/src/dpdk/examples/timer/main.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 <string.h>
  36 #include <stdint.h>
  37 #include <errno.h>
  38 #include <sys/queue.h>
  39
  40 #include <rte_common.h>
  41 #include <rte_memory.h>
  42 #include <rte_memzone.h>
  43 #include <rte_launch.h>
  44 #include <rte_eal.h>
  45 #include <rte_per_lcore.h>
  46 #include <rte_lcore.h>
  47 #include <rte_cycles.h>
  48 #include <rte_timer.h>
  49 #include <rte_debug.h>
  50
  51 #define TIMER_RESOLUTION_CYCLES 20000000ULL /* around 10ms at 2 Ghz */
  52
  53 static struct rte_timer timer0;
  54 static struct rte_timer timer1;
  55
  56 /* timer0 callback */
  57 static void
  58 timer0_cb(__attribute__((unused)) struct rte_timer *tim,
  59           __attribute__((unused)) void *arg)
  60 {
  61         static unsigned counter = 0;
  62         unsigned lcore_id = rte_lcore_id();
  63
  64         printf("%s() on lcore %u\n", __func__, lcore_id);
  65
  66         /* this timer is automatically reloaded until we decide to
  67          * stop it, when counter reaches 20. */
  68         if ((counter ++) == 20)
  69                 rte_timer_stop(tim);
  70 }
  71
  72 /* timer1 callback */
  73 static void
  74 timer1_cb(__attribute__((unused)) struct rte_timer *tim,
  75           __attribute__((unused)) void *arg)
  76 {
  77         unsigned lcore_id = rte_lcore_id();
  78         uint64_t hz;
  79
  80         printf("%s() on lcore %u\n", __func__, lcore_id);
  81
  82         /* reload it on another lcore */
  83         hz = rte_get_timer_hz();
  84         lcore_id = rte_get_next_lcore(lcore_id, 0, 1);
  85         rte_timer_reset(tim, hz/3, SINGLE, lcore_id, timer1_cb, NULL);
  86 }
  87
  88 static __attribute__((noreturn)) int
  89 lcore_mainloop(__attribute__((unused)) void *arg)
  90 {
  91         uint64_t prev_tsc = 0, cur_tsc, diff_tsc;
  92         unsigned lcore_id;
  93
  94         lcore_id = rte_lcore_id();
  95         printf("Starting mainloop on core %u\n", lcore_id);
  96
  97         while (1) {
  98                 /*
  99                  * Call the timer handler on each core: as we don't
 100                  * need a very precise timer, so only call
 101                  * rte_timer_manage() every ~10ms (at 2Ghz). In a real
 102                  * application, this will enhance performances as
 103                  * reading the HPET timer is not efficient.
 104                  */
 105                 cur_tsc = rte_rdtsc();
 106                 diff_tsc = cur_tsc - prev_tsc;
 107                 if (diff_tsc > TIMER_RESOLUTION_CYCLES) {
 108                         rte_timer_manage();
 109                         prev_tsc = cur_tsc;
 110                 }
 111         }
 112 }
 113
 114 int
 115 main(int argc, char **argv)
 116 {
 117         int ret;
 118         uint64_t hz;
 119         unsigned lcore_id;
 120
 121         /* init EAL */
 122         ret = rte_eal_init(argc, argv);
 123         if (ret < 0)
 124                 rte_panic("Cannot init EAL\n");
 125
 126         /* init RTE timer library */
 127         rte_timer_subsystem_init();
 128
 129         /* init timer structures */
 130         rte_timer_init(&timer0);
 131         rte_timer_init(&timer1);
 132
 133         /* load timer0, every second, on master lcore, reloaded automatically */
 134         hz = rte_get_timer_hz();
 135         lcore_id = rte_lcore_id();
 136         rte_timer_reset(&timer0, hz, PERIODICAL, lcore_id, timer0_cb, NULL);
 137
 138         /* load timer1, every second/3, on next lcore, reloaded manually */
 139         lcore_id = rte_get_next_lcore(lcore_id, 0, 1);
 140         rte_timer_reset(&timer1, hz/3, SINGLE, lcore_id, timer1_cb, NULL);
 141
 142         /* call lcore_mainloop() on every slave lcore */
 143         RTE_LCORE_FOREACH_SLAVE(lcore_id) {
 144                 rte_eal_remote_launch(lcore_mainloop, NULL, lcore_id);
 145         }
 146
 147         /* call it on master lcore too */
 148         (void) lcore_mainloop(NULL);
 149
 150         return 0;
 151 }