app/test/test_ticketlock.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2018-2019 Arm Limited
   3  */
   4
   5 #include <inttypes.h>
   6 #include <stdint.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <sys/queue.h>
  10 #include <unistd.h>
  11
  12 #include <rte_atomic.h>
  13 #include <rte_common.h>
  14 #include <rte_cycles.h>
  15 #include <rte_eal.h>
  16 #include <rte_launch.h>
  17 #include <rte_lcore.h>
  18 #include <rte_memory.h>
  19 #include <rte_per_lcore.h>
  20 #include <rte_ticketlock.h>
  21
  22 #include "test.h"
  23
  24 /*
  25  * Ticketlock test
  26  * =============
  27  *
  28  * - There is a global ticketlock and a table of ticketlocks (one per lcore).
  29  *
  30  * - The test function takes all of these locks and launches the
  31  *   ``test_ticketlock_per_core()`` function on each core (except the main).
  32  *
  33  *   - The function takes the global lock, display something, then releases
  34  *     the global lock.
  35  *   - The function takes the per-lcore lock, display something, then releases
  36  *     the per-core lock.
  37  *
  38  * - The main function unlocks the per-lcore locks sequentially and
  39  *   waits between each lock. This triggers the display of a message
  40  *   for each core, in the correct order. The autotest script checks that
  41  *   this order is correct.
  42  *
  43  * - A load test is carried out, with all cores attempting to lock a single lock
  44  *   multiple times
  45  */
  46
  47 static rte_ticketlock_t tl, tl_try;
  48 static rte_ticketlock_t tl_tab[RTE_MAX_LCORE];
  49 static rte_ticketlock_recursive_t tlr;
  50 static unsigned int count;
  51
  52 static rte_atomic32_t synchro;
  53
  54 static int
  55 test_ticketlock_per_core(__rte_unused void *arg)
  56 {
  57         rte_ticketlock_lock(&tl);
  58         printf("Global lock taken on core %u\n", rte_lcore_id());
  59         rte_ticketlock_unlock(&tl);
  60
  61         rte_ticketlock_lock(&tl_tab[rte_lcore_id()]);
  62         printf("Hello from core %u !\n", rte_lcore_id());
  63         rte_ticketlock_unlock(&tl_tab[rte_lcore_id()]);
  64
  65         return 0;
  66 }
  67
  68 static int
  69 test_ticketlock_recursive_per_core(__rte_unused void *arg)
  70 {
  71         unsigned int id = rte_lcore_id();
  72
  73         rte_ticketlock_recursive_lock(&tlr);
  74         printf("Global recursive lock taken on core %u - count = %d\n",
  75                id, tlr.count);
  76         rte_ticketlock_recursive_lock(&tlr);
  77         printf("Global recursive lock taken on core %u - count = %d\n",
  78                id, tlr.count);
  79         rte_ticketlock_recursive_lock(&tlr);
  80         printf("Global recursive lock taken on core %u - count = %d\n",
  81                id, tlr.count);
  82
  83         printf("Hello from within recursive locks from core %u !\n", id);
  84
  85         rte_ticketlock_recursive_unlock(&tlr);
  86         printf("Global recursive lock released on core %u - count = %d\n",
  87                id, tlr.count);
  88         rte_ticketlock_recursive_unlock(&tlr);
  89         printf("Global recursive lock released on core %u - count = %d\n",
  90                id, tlr.count);
  91         rte_ticketlock_recursive_unlock(&tlr);
  92         printf("Global recursive lock released on core %u - count = %d\n",
  93                id, tlr.count);
  94
  95         return 0;
  96 }
  97
  98 static rte_ticketlock_t lk = RTE_TICKETLOCK_INITIALIZER;
  99 static uint64_t lcount __rte_cache_aligned;
 100 static uint64_t lcore_count[RTE_MAX_LCORE] __rte_cache_aligned;
 101 static uint64_t time_cost[RTE_MAX_LCORE];
 102
 103 #define MAX_LOOP 10000
 104
 105 static int
 106 load_loop_fn(void *func_param)
 107 {
 108         uint64_t time_diff = 0, begin;
 109         uint64_t hz = rte_get_timer_hz();
 110         const int use_lock = *(int *)func_param;
 111         const unsigned int lcore = rte_lcore_id();
 112
 113         /* wait synchro for workers */
 114         if (lcore != rte_get_main_lcore())
 115                 while (rte_atomic32_read(&synchro) == 0)
 116                         ;
 117
 118         begin = rte_rdtsc_precise();
 119         while (lcore_count[lcore] < MAX_LOOP) {
 120                 if (use_lock)
 121                         rte_ticketlock_lock(&lk);
 122                 lcore_count[lcore]++;
 123                 lcount++;
 124                 if (use_lock)
 125                         rte_ticketlock_unlock(&lk);
 126         }
 127         time_diff = rte_rdtsc_precise() - begin;
 128         time_cost[lcore] = time_diff * 1000000 / hz;
 129         return 0;
 130 }
 131
 132 static int
 133 test_ticketlock_perf(void)
 134 {
 135         unsigned int i;
 136         uint64_t tcount = 0;
 137         uint64_t total_time = 0;
 138         int lock = 0;
 139         const unsigned int lcore = rte_lcore_id();
 140
 141         printf("\nTest with no lock on single core...\n");
 142         load_loop_fn(&lock);
 143         printf("Core [%u] cost time = %"PRIu64" us\n", lcore, time_cost[lcore]);
 144         memset(lcore_count, 0, sizeof(lcore_count));
 145         memset(time_cost, 0, sizeof(time_cost));
 146
 147         printf("\nTest with lock on single core...\n");
 148         lock = 1;
 149         load_loop_fn(&lock);
 150         printf("Core [%u] cost time = %"PRIu64" us\n", lcore, time_cost[lcore]);
 151         memset(lcore_count, 0, sizeof(lcore_count));
 152         memset(time_cost, 0, sizeof(time_cost));
 153
 154         lcount = 0;
 155         printf("\nTest with lock on %u cores...\n", rte_lcore_count());
 156
 157         /* Clear synchro and start workers */
 158         rte_atomic32_set(&synchro, 0);
 159         rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MAIN);
 160
 161         /* start synchro and launch test on main */
 162         rte_atomic32_set(&synchro, 1);
 163         load_loop_fn(&lock);
 164
 165         rte_eal_mp_wait_lcore();
 166
 167         RTE_LCORE_FOREACH(i) {
 168                 printf("Core [%u] cost time = %"PRIu64" us\n", i, time_cost[i]);
 169                 tcount += lcore_count[i];
 170                 total_time += time_cost[i];
 171         }
 172
 173         if (tcount != lcount)
 174                 return -1;
 175
 176         printf("Total cost time = %"PRIu64" us\n", total_time);
 177
 178         return 0;
 179 }
 180
 181 /*
 182  * Use rte_ticketlock_trylock() to trylock a ticketlock object,
 183  * If it could not lock the object successfully, it would
 184  * return immediately and the variable of "count" would be
 185  * increased by one per times. the value of "count" could be
 186  * checked as the result later.
 187  */
 188 static int
 189 test_ticketlock_try(__rte_unused void *arg)
 190 {
 191         if (rte_ticketlock_trylock(&tl_try) == 0) {
 192                 rte_ticketlock_lock(&tl);
 193                 count++;
 194                 rte_ticketlock_unlock(&tl);
 195         }
 196
 197         return 0;
 198 }
 199
 200
 201 /*
 202  * Test rte_eal_get_lcore_state() in addition to ticketlocks
 203  * as we have "waiting" then "running" lcores.
 204  */
 205 static int
 206 test_ticketlock(void)
 207 {
 208         int ret = 0;
 209         int i;
 210
 211         /* worker cores should be waiting: print it */
 212         RTE_LCORE_FOREACH_WORKER(i) {
 213                 printf("lcore %d state: %d\n", i,
 214                        (int) rte_eal_get_lcore_state(i));
 215         }
 216
 217         rte_ticketlock_init(&tl);
 218         rte_ticketlock_init(&tl_try);
 219         rte_ticketlock_recursive_init(&tlr);
 220         RTE_LCORE_FOREACH_WORKER(i) {
 221                 rte_ticketlock_init(&tl_tab[i]);
 222         }
 223
 224         rte_ticketlock_lock(&tl);
 225
 226         RTE_LCORE_FOREACH_WORKER(i) {
 227                 rte_ticketlock_lock(&tl_tab[i]);
 228                 rte_eal_remote_launch(test_ticketlock_per_core, NULL, i);
 229         }
 230
 231         /* worker cores should be busy: print it */
 232         RTE_LCORE_FOREACH_WORKER(i) {
 233                 printf("lcore %d state: %d\n", i,
 234                        (int) rte_eal_get_lcore_state(i));
 235         }
 236         rte_ticketlock_unlock(&tl);
 237
 238         RTE_LCORE_FOREACH_WORKER(i) {
 239                 rte_ticketlock_unlock(&tl_tab[i]);
 240                 rte_delay_ms(10);
 241         }
 242
 243         rte_eal_mp_wait_lcore();
 244
 245         rte_ticketlock_recursive_lock(&tlr);
 246
 247         /*
 248          * Try to acquire a lock that we already own
 249          */
 250         if (!rte_ticketlock_recursive_trylock(&tlr)) {
 251                 printf("rte_ticketlock_recursive_trylock failed on a lock that "
 252                        "we already own\n");
 253                 ret = -1;
 254         } else
 255                 rte_ticketlock_recursive_unlock(&tlr);
 256
 257         RTE_LCORE_FOREACH_WORKER(i) {
 258                 rte_eal_remote_launch(test_ticketlock_recursive_per_core,
 259                                         NULL, i);
 260         }
 261         rte_ticketlock_recursive_unlock(&tlr);
 262         rte_eal_mp_wait_lcore();
 263
 264         /*
 265          * Test if it could return immediately from try-locking a locked object.
 266          * Here it will lock the ticketlock object first, then launch all the
 267          * worker lcores to trylock the same ticketlock object.
 268          * All the worker lcores should give up try-locking a locked object and
 269          * return immediately, and then increase the "count" initialized with
 270          * zero by one per times.
 271          * We can check if the "count" is finally equal to the number of all
 272          * worker lcores to see if the behavior of try-locking a locked
 273          * ticketlock object is correct.
 274          */
 275         if (rte_ticketlock_trylock(&tl_try) == 0)
 276                 return -1;
 277
 278         count = 0;
 279         RTE_LCORE_FOREACH_WORKER(i) {
 280                 rte_eal_remote_launch(test_ticketlock_try, NULL, i);
 281         }
 282         rte_eal_mp_wait_lcore();
 283         rte_ticketlock_unlock(&tl_try);
 284         if (rte_ticketlock_is_locked(&tl)) {
 285                 printf("ticketlock is locked but it should not be\n");
 286                 return -1;
 287         }
 288         rte_ticketlock_lock(&tl);
 289         if (count != (rte_lcore_count() - 1))
 290                 ret = -1;
 291
 292         rte_ticketlock_unlock(&tl);
 293
 294         /*
 295          * Test if it can trylock recursively.
 296          * Use rte_ticketlock_recursive_trylock() to check if it can lock
 297          * a ticketlock object recursively. Here it will try to lock a
 298          * ticketlock object twice.
 299          */
 300         if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
 301                 printf("It failed to do the first ticketlock_recursive_trylock "
 302                            "but it should able to do\n");
 303                 return -1;
 304         }
 305         if (rte_ticketlock_recursive_trylock(&tlr) == 0) {
 306                 printf("It failed to do the second ticketlock_recursive_trylock "
 307                            "but it should able to do\n");
 308                 return -1;
 309         }
 310         rte_ticketlock_recursive_unlock(&tlr);
 311         rte_ticketlock_recursive_unlock(&tlr);
 312
 313         if (test_ticketlock_perf() < 0)
 314                 return -1;
 315
 316         return ret;
 317 }
 318
 319 REGISTER_TEST_COMMAND(ticketlock_autotest, test_ticketlock);