app/test/test_spinlock.c

   1 /*-
   2  *   BSD LICENSE
   3  *
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  10  *
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  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  *
  33  */
  34
  35 #include <stdio.h>
  36 #include <stdint.h>
  37 #include <inttypes.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <sys/queue.h>
  41
  42 #include <cmdline_parse.h>
  43
  44 #include <rte_common.h>
  45 #include <rte_memory.h>
  46 #include <rte_memzone.h>
  47 #include <rte_per_lcore.h>
  48 #include <rte_launch.h>
  49 #include <rte_tailq.h>
  50 #include <rte_eal.h>
  51 #include <rte_per_lcore.h>
  52 #include <rte_lcore.h>
  53 #include <rte_cycles.h>
  54 #include <rte_spinlock.h>
  55 #include <rte_atomic.h>
  56
  57 #include "test.h"
  58
  59 /*
  60  * Spinlock test
  61  * =============
  62  *
  63  * - There is a global spinlock and a table of spinlocks (one per lcore).
  64  *
  65  * - The test function takes all of these locks and launches the
  66  *   ``test_spinlock_per_core()`` function on each core (except the master).
  67  *
  68  *   - The function takes the global lock, display something, then releases
  69  *     the global lock.
  70  *   - The function takes the per-lcore lock, display something, then releases
  71  *     the per-core lock.
  72  *
  73  * - The main function unlocks the per-lcore locks sequentially and
  74  *   waits between each lock. This triggers the display of a message
  75  *   for each core, in the correct order. The autotest script checks that
  76  *   this order is correct.
  77  *
  78  * - A load test is carried out, with all cores attempting to lock a single lock
  79  *   multiple times
  80  */
  81
  82 static rte_spinlock_t sl, sl_try;
  83 static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
  84 static rte_spinlock_recursive_t slr;
  85 static unsigned count = 0;
  86
  87 static rte_atomic32_t synchro;
  88
  89 static int
  90 test_spinlock_per_core(__attribute__((unused)) void *arg)
  91 {
  92         rte_spinlock_lock(&sl);
  93         printf("Global lock taken on core %u\n", rte_lcore_id());
  94         rte_spinlock_unlock(&sl);
  95
  96         rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
  97         printf("Hello from core %u !\n", rte_lcore_id());
  98         rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);
  99
 100         return 0;
 101 }
 102
 103 static int
 104 test_spinlock_recursive_per_core(__attribute__((unused)) void *arg)
 105 {
 106         unsigned id = rte_lcore_id();
 107
 108         rte_spinlock_recursive_lock(&slr);
 109         printf("Global recursive lock taken on core %u - count = %d\n",
 110                id, slr.count);
 111         rte_spinlock_recursive_lock(&slr);
 112         printf("Global recursive lock taken on core %u - count = %d\n",
 113                id, slr.count);
 114         rte_spinlock_recursive_lock(&slr);
 115         printf("Global recursive lock taken on core %u - count = %d\n",
 116                id, slr.count);
 117
 118         printf("Hello from within recursive locks from core %u !\n", id);
 119
 120         rte_spinlock_recursive_unlock(&slr);
 121         printf("Global recursive lock released on core %u - count = %d\n",
 122                id, slr.count);
 123         rte_spinlock_recursive_unlock(&slr);
 124         printf("Global recursive lock released on core %u - count = %d\n",
 125                id, slr.count);
 126         rte_spinlock_recursive_unlock(&slr);
 127         printf("Global recursive lock released on core %u - count = %d\n",
 128                id, slr.count);
 129
 130         return 0;
 131 }
 132
 133 static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
 134 static uint64_t lock_count[RTE_MAX_LCORE] = {0};
 135
 136 #define TIME_S 5
 137
 138 static int
 139 load_loop_fn(void *func_param)
 140 {
 141         uint64_t time_diff = 0, begin;
 142         uint64_t hz = rte_get_hpet_hz();
 143         uint64_t lcount = 0;
 144         const int use_lock = *(int*)func_param;
 145         const unsigned lcore = rte_lcore_id();
 146
 147         /* wait synchro for slaves */
 148         if (lcore != rte_get_master_lcore())
 149                 while (rte_atomic32_read(&synchro) == 0);
 150
 151         begin = rte_get_hpet_cycles();
 152         while (time_diff / hz < TIME_S) {
 153                 if (use_lock)
 154                         rte_spinlock_lock(&lk);
 155                 lcount++;
 156                 if (use_lock)
 157                         rte_spinlock_unlock(&lk);
 158                 /* delay to make lock duty cycle slighlty realistic */
 159                 rte_delay_us(1);
 160                 time_diff = rte_get_hpet_cycles() - begin;
 161         }
 162         lock_count[lcore] = lcount;
 163         return 0;
 164 }
 165
 166 static int
 167 test_spinlock_perf(void)
 168 {
 169         unsigned int i;
 170         uint64_t total = 0;
 171         int lock = 0;
 172         const unsigned lcore = rte_lcore_id();
 173
 174         printf("\nTest with no lock on single core...\n");
 175         load_loop_fn(&lock);
 176         printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
 177         memset(lock_count, 0, sizeof(lock_count));
 178
 179         printf("\nTest with lock on single core...\n");
 180         lock = 1;
 181         load_loop_fn(&lock);
 182         printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
 183         memset(lock_count, 0, sizeof(lock_count));
 184
 185         printf("\nTest with lock on %u cores...\n", rte_lcore_count());
 186
 187         /* Clear synchro and start slaves */
 188         rte_atomic32_set(&synchro, 0);
 189         rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
 190
 191         /* start synchro and launch test on master */
 192         rte_atomic32_set(&synchro, 1);
 193         load_loop_fn(&lock);
 194
 195         rte_eal_mp_wait_lcore();
 196
 197         RTE_LCORE_FOREACH(i) {
 198                 printf("Core [%u] count = %"PRIu64"\n", i, lock_count[i]);
 199                 total += lock_count[i];
 200         }
 201
 202         printf("Total count = %"PRIu64"\n", total);
 203
 204         return 0;
 205 }
 206
 207 /*
 208  * Use rte_spinlock_trylock() to trylock a spinlock object,
 209  * If it could not lock the object sucessfully, it would
 210  * return immediately and the variable of "count" would be
 211  * increased by one per times. the value of "count" could be
 212  * checked as the result later.
 213  */
 214 static int
 215 test_spinlock_try(__attribute__((unused)) void *arg)
 216 {
 217         if (rte_spinlock_trylock(&sl_try) == 0) {
 218                 rte_spinlock_lock(&sl);
 219                 count ++;
 220                 rte_spinlock_unlock(&sl);
 221         }
 222
 223         return 0;
 224 }
 225
 226
 227 /*
 228  * Test rte_eal_get_lcore_state() in addition to spinlocks
 229  * as we have "waiting" then "running" lcores.
 230  */
 231 int
 232 test_spinlock(void)
 233 {
 234         int ret = 0;
 235         int i;
 236
 237         /* slave cores should be waiting: print it */
 238         RTE_LCORE_FOREACH_SLAVE(i) {
 239                 printf("lcore %d state: %d\n", i,
 240                        (int) rte_eal_get_lcore_state(i));
 241         }
 242
 243         rte_spinlock_init(&sl);
 244         rte_spinlock_init(&sl_try);
 245         rte_spinlock_recursive_init(&slr);
 246         for (i=0; i<RTE_MAX_LCORE; i++)
 247                 rte_spinlock_init(&sl_tab[i]);
 248
 249         rte_spinlock_lock(&sl);
 250
 251         RTE_LCORE_FOREACH_SLAVE(i) {
 252                 rte_spinlock_lock(&sl_tab[i]);
 253                 rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
 254         }
 255
 256         /* slave cores should be busy: print it */
 257         RTE_LCORE_FOREACH_SLAVE(i) {
 258                 printf("lcore %d state: %d\n", i,
 259                        (int) rte_eal_get_lcore_state(i));
 260         }
 261         rte_spinlock_unlock(&sl);
 262
 263         RTE_LCORE_FOREACH_SLAVE(i) {
 264                 rte_spinlock_unlock(&sl_tab[i]);
 265                 rte_delay_ms(100);
 266         }
 267
 268         rte_eal_mp_wait_lcore();
 269
 270         rte_spinlock_recursive_lock(&slr);
 271
 272         /*
 273          * Try to acquire a lock that we already own
 274          */
 275         if(!rte_spinlock_recursive_trylock(&slr)) {
 276                 printf("rte_spinlock_recursive_trylock failed on a lock that "
 277                        "we already own\n");
 278                 ret = -1;
 279         } else
 280                 rte_spinlock_recursive_unlock(&slr);
 281
 282         RTE_LCORE_FOREACH_SLAVE(i) {
 283                 rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
 284         }
 285         rte_spinlock_recursive_unlock(&slr);
 286         rte_eal_mp_wait_lcore();
 287
 288         /*
 289          * Test if it could return immediately from try-locking a locked object.
 290          * Here it will lock the spinlock object first, then launch all the slave
 291          * lcores to trylock the same spinlock object.
 292          * All the slave lcores should give up try-locking a locked object and
 293          * return immediately, and then increase the "count" initialized with zero
 294          * by one per times.
 295          * We can check if the "count" is finally equal to the number of all slave
 296          * lcores to see if the behavior of try-locking a locked spinlock object
 297          * is correct.
 298          */
 299         if (rte_spinlock_trylock(&sl_try) == 0) {
 300                 return -1;
 301         }
 302         count = 0;
 303         RTE_LCORE_FOREACH_SLAVE(i) {
 304                 rte_eal_remote_launch(test_spinlock_try, NULL, i);
 305         }
 306         rte_eal_mp_wait_lcore();
 307         rte_spinlock_unlock(&sl_try);
 308         if (rte_spinlock_is_locked(&sl)) {
 309                 printf("spinlock is locked but it should not be\n");
 310                 return -1;
 311         }
 312         rte_spinlock_lock(&sl);
 313         if (count != ( rte_lcore_count() - 1)) {
 314                 ret = -1;
 315         }
 316         rte_spinlock_unlock(&sl);
 317
 318         /*
 319          * Test if it can trylock recursively.
 320          * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
 321          * object recursively. Here it will try to lock a spinlock object twice.
 322          */
 323         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 324                 printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
 325                 return -1;
 326         }
 327         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 328                 printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
 329                 return -1;
 330         }
 331         rte_spinlock_recursive_unlock(&slr);
 332         rte_spinlock_recursive_unlock(&slr);
 333
 334         if (test_spinlock_perf() < 0)
 335                 return -1;
 336
 337         return ret;
 338 }