test/test/test_spinlock.c

   1 /*-
   2  *   BSD LICENSE
   3  *
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  10  *
  11  *     * Redistributions of source code must retain the above copyright
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  31  *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdint.h>
  36 #include <inttypes.h>
  37 #include <string.h>
  38 #include <unistd.h>
  39 #include <sys/queue.h>
  40
  41 #include <rte_common.h>
  42 #include <rte_memory.h>
  43 #include <rte_memzone.h>
  44 #include <rte_per_lcore.h>
  45 #include <rte_launch.h>
  46 #include <rte_eal.h>
  47 #include <rte_lcore.h>
  48 #include <rte_cycles.h>
  49 #include <rte_spinlock.h>
  50 #include <rte_atomic.h>
  51
  52 #include "test.h"
  53
  54 /*
  55  * Spinlock test
  56  * =============
  57  *
  58  * - There is a global spinlock and a table of spinlocks (one per lcore).
  59  *
  60  * - The test function takes all of these locks and launches the
  61  *   ``test_spinlock_per_core()`` function on each core (except the master).
  62  *
  63  *   - The function takes the global lock, display something, then releases
  64  *     the global lock.
  65  *   - The function takes the per-lcore lock, display something, then releases
  66  *     the per-core lock.
  67  *
  68  * - The main function unlocks the per-lcore locks sequentially and
  69  *   waits between each lock. This triggers the display of a message
  70  *   for each core, in the correct order. The autotest script checks that
  71  *   this order is correct.
  72  *
  73  * - A load test is carried out, with all cores attempting to lock a single lock
  74  *   multiple times
  75  */
  76
  77 static rte_spinlock_t sl, sl_try;
  78 static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
  79 static rte_spinlock_recursive_t slr;
  80 static unsigned count = 0;
  81
  82 static rte_atomic32_t synchro;
  83
  84 static int
  85 test_spinlock_per_core(__attribute__((unused)) void *arg)
  86 {
  87         rte_spinlock_lock(&sl);
  88         printf("Global lock taken on core %u\n", rte_lcore_id());
  89         rte_spinlock_unlock(&sl);
  90
  91         rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
  92         printf("Hello from core %u !\n", rte_lcore_id());
  93         rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);
  94
  95         return 0;
  96 }
  97
  98 static int
  99 test_spinlock_recursive_per_core(__attribute__((unused)) void *arg)
 100 {
 101         unsigned id = rte_lcore_id();
 102
 103         rte_spinlock_recursive_lock(&slr);
 104         printf("Global recursive lock taken on core %u - count = %d\n",
 105                id, slr.count);
 106         rte_spinlock_recursive_lock(&slr);
 107         printf("Global recursive lock taken on core %u - count = %d\n",
 108                id, slr.count);
 109         rte_spinlock_recursive_lock(&slr);
 110         printf("Global recursive lock taken on core %u - count = %d\n",
 111                id, slr.count);
 112
 113         printf("Hello from within recursive locks from core %u !\n", id);
 114
 115         rte_spinlock_recursive_unlock(&slr);
 116         printf("Global recursive lock released on core %u - count = %d\n",
 117                id, slr.count);
 118         rte_spinlock_recursive_unlock(&slr);
 119         printf("Global recursive lock released on core %u - count = %d\n",
 120                id, slr.count);
 121         rte_spinlock_recursive_unlock(&slr);
 122         printf("Global recursive lock released on core %u - count = %d\n",
 123                id, slr.count);
 124
 125         return 0;
 126 }
 127
 128 static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
 129 static uint64_t lock_count[RTE_MAX_LCORE] = {0};
 130
 131 #define TIME_MS 100
 132
 133 static int
 134 load_loop_fn(void *func_param)
 135 {
 136         uint64_t time_diff = 0, begin;
 137         uint64_t hz = rte_get_timer_hz();
 138         uint64_t lcount = 0;
 139         const int use_lock = *(int*)func_param;
 140         const unsigned lcore = rte_lcore_id();
 141
 142         /* wait synchro for slaves */
 143         if (lcore != rte_get_master_lcore())
 144                 while (rte_atomic32_read(&synchro) == 0);
 145
 146         begin = rte_get_timer_cycles();
 147         while (time_diff < hz * TIME_MS / 1000) {
 148                 if (use_lock)
 149                         rte_spinlock_lock(&lk);
 150                 lcount++;
 151                 if (use_lock)
 152                         rte_spinlock_unlock(&lk);
 153                 /* delay to make lock duty cycle slighlty realistic */
 154                 rte_delay_us(1);
 155                 time_diff = rte_get_timer_cycles() - begin;
 156         }
 157         lock_count[lcore] = lcount;
 158         return 0;
 159 }
 160
 161 static int
 162 test_spinlock_perf(void)
 163 {
 164         unsigned int i;
 165         uint64_t total = 0;
 166         int lock = 0;
 167         const unsigned lcore = rte_lcore_id();
 168
 169         printf("\nTest with no lock on single core...\n");
 170         load_loop_fn(&lock);
 171         printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
 172         memset(lock_count, 0, sizeof(lock_count));
 173
 174         printf("\nTest with lock on single core...\n");
 175         lock = 1;
 176         load_loop_fn(&lock);
 177         printf("Core [%u] count = %"PRIu64"\n", lcore, lock_count[lcore]);
 178         memset(lock_count, 0, sizeof(lock_count));
 179
 180         printf("\nTest with lock on %u cores...\n", rte_lcore_count());
 181
 182         /* Clear synchro and start slaves */
 183         rte_atomic32_set(&synchro, 0);
 184         rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
 185
 186         /* start synchro and launch test on master */
 187         rte_atomic32_set(&synchro, 1);
 188         load_loop_fn(&lock);
 189
 190         rte_eal_mp_wait_lcore();
 191
 192         RTE_LCORE_FOREACH(i) {
 193                 printf("Core [%u] count = %"PRIu64"\n", i, lock_count[i]);
 194                 total += lock_count[i];
 195         }
 196
 197         printf("Total count = %"PRIu64"\n", total);
 198
 199         return 0;
 200 }
 201
 202 /*
 203  * Use rte_spinlock_trylock() to trylock a spinlock object,
 204  * If it could not lock the object successfully, it would
 205  * return immediately and the variable of "count" would be
 206  * increased by one per times. the value of "count" could be
 207  * checked as the result later.
 208  */
 209 static int
 210 test_spinlock_try(__attribute__((unused)) void *arg)
 211 {
 212         if (rte_spinlock_trylock(&sl_try) == 0) {
 213                 rte_spinlock_lock(&sl);
 214                 count ++;
 215                 rte_spinlock_unlock(&sl);
 216         }
 217
 218         return 0;
 219 }
 220
 221
 222 /*
 223  * Test rte_eal_get_lcore_state() in addition to spinlocks
 224  * as we have "waiting" then "running" lcores.
 225  */
 226 static int
 227 test_spinlock(void)
 228 {
 229         int ret = 0;
 230         int i;
 231
 232         /* slave cores should be waiting: print it */
 233         RTE_LCORE_FOREACH_SLAVE(i) {
 234                 printf("lcore %d state: %d\n", i,
 235                        (int) rte_eal_get_lcore_state(i));
 236         }
 237
 238         rte_spinlock_init(&sl);
 239         rte_spinlock_init(&sl_try);
 240         rte_spinlock_recursive_init(&slr);
 241         for (i=0; i<RTE_MAX_LCORE; i++)
 242                 rte_spinlock_init(&sl_tab[i]);
 243
 244         rte_spinlock_lock(&sl);
 245
 246         RTE_LCORE_FOREACH_SLAVE(i) {
 247                 rte_spinlock_lock(&sl_tab[i]);
 248                 rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
 249         }
 250
 251         /* slave cores should be busy: print it */
 252         RTE_LCORE_FOREACH_SLAVE(i) {
 253                 printf("lcore %d state: %d\n", i,
 254                        (int) rte_eal_get_lcore_state(i));
 255         }
 256         rte_spinlock_unlock(&sl);
 257
 258         RTE_LCORE_FOREACH_SLAVE(i) {
 259                 rte_spinlock_unlock(&sl_tab[i]);
 260                 rte_delay_ms(10);
 261         }
 262
 263         rte_eal_mp_wait_lcore();
 264
 265         rte_spinlock_recursive_lock(&slr);
 266
 267         /*
 268          * Try to acquire a lock that we already own
 269          */
 270         if(!rte_spinlock_recursive_trylock(&slr)) {
 271                 printf("rte_spinlock_recursive_trylock failed on a lock that "
 272                        "we already own\n");
 273                 ret = -1;
 274         } else
 275                 rte_spinlock_recursive_unlock(&slr);
 276
 277         RTE_LCORE_FOREACH_SLAVE(i) {
 278                 rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
 279         }
 280         rte_spinlock_recursive_unlock(&slr);
 281         rte_eal_mp_wait_lcore();
 282
 283         /*
 284          * Test if it could return immediately from try-locking a locked object.
 285          * Here it will lock the spinlock object first, then launch all the slave
 286          * lcores to trylock the same spinlock object.
 287          * All the slave lcores should give up try-locking a locked object and
 288          * return immediately, and then increase the "count" initialized with zero
 289          * by one per times.
 290          * We can check if the "count" is finally equal to the number of all slave
 291          * lcores to see if the behavior of try-locking a locked spinlock object
 292          * is correct.
 293          */
 294         if (rte_spinlock_trylock(&sl_try) == 0) {
 295                 return -1;
 296         }
 297         count = 0;
 298         RTE_LCORE_FOREACH_SLAVE(i) {
 299                 rte_eal_remote_launch(test_spinlock_try, NULL, i);
 300         }
 301         rte_eal_mp_wait_lcore();
 302         rte_spinlock_unlock(&sl_try);
 303         if (rte_spinlock_is_locked(&sl)) {
 304                 printf("spinlock is locked but it should not be\n");
 305                 return -1;
 306         }
 307         rte_spinlock_lock(&sl);
 308         if (count != ( rte_lcore_count() - 1)) {
 309                 ret = -1;
 310         }
 311         rte_spinlock_unlock(&sl);
 312
 313         /*
 314          * Test if it can trylock recursively.
 315          * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
 316          * object recursively. Here it will try to lock a spinlock object twice.
 317          */
 318         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 319                 printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
 320                 return -1;
 321         }
 322         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 323                 printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
 324                 return -1;
 325         }
 326         rte_spinlock_recursive_unlock(&slr);
 327         rte_spinlock_recursive_unlock(&slr);
 328
 329         if (test_spinlock_perf() < 0)
 330                 return -1;
 331
 332         return ret;
 333 }
 334
 335 REGISTER_TEST_COMMAND(spinlock_autotest, test_spinlock);