ceph/src/seastar/dpdk/app/test/test_spinlock.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2014 Intel Corporation
   3  */
   4
   5 #include <stdio.h>
   6 #include <stdint.h>
   7 #include <inttypes.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10 #include <sys/queue.h>
  11
  12 #include <rte_common.h>
  13 #include <rte_memory.h>
  14 #include <rte_per_lcore.h>
  15 #include <rte_launch.h>
  16 #include <rte_eal.h>
  17 #include <rte_lcore.h>
  18 #include <rte_cycles.h>
  19 #include <rte_spinlock.h>
  20 #include <rte_atomic.h>
  21
  22 #include "test.h"
  23
  24 /*
  25  * Spinlock test
  26  * =============
  27  *
  28  * - There is a global spinlock and a table of spinlocks (one per lcore).
  29  *
  30  * - The test function takes all of these locks and launches the
  31  *   ``test_spinlock_per_core()`` function on each core (except the master).
  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_spinlock_t sl, sl_try;
  48 static rte_spinlock_t sl_tab[RTE_MAX_LCORE];
  49 static rte_spinlock_recursive_t slr;
  50 static unsigned count = 0;
  51
  52 static rte_atomic32_t synchro;
  53
  54 static int
  55 test_spinlock_per_core(__attribute__((unused)) void *arg)
  56 {
  57         rte_spinlock_lock(&sl);
  58         printf("Global lock taken on core %u\n", rte_lcore_id());
  59         rte_spinlock_unlock(&sl);
  60
  61         rte_spinlock_lock(&sl_tab[rte_lcore_id()]);
  62         printf("Hello from core %u !\n", rte_lcore_id());
  63         rte_spinlock_unlock(&sl_tab[rte_lcore_id()]);
  64
  65         return 0;
  66 }
  67
  68 static int
  69 test_spinlock_recursive_per_core(__attribute__((unused)) void *arg)
  70 {
  71         unsigned id = rte_lcore_id();
  72
  73         rte_spinlock_recursive_lock(&slr);
  74         printf("Global recursive lock taken on core %u - count = %d\n",
  75                id, slr.count);
  76         rte_spinlock_recursive_lock(&slr);
  77         printf("Global recursive lock taken on core %u - count = %d\n",
  78                id, slr.count);
  79         rte_spinlock_recursive_lock(&slr);
  80         printf("Global recursive lock taken on core %u - count = %d\n",
  81                id, slr.count);
  82
  83         printf("Hello from within recursive locks from core %u !\n", id);
  84
  85         rte_spinlock_recursive_unlock(&slr);
  86         printf("Global recursive lock released on core %u - count = %d\n",
  87                id, slr.count);
  88         rte_spinlock_recursive_unlock(&slr);
  89         printf("Global recursive lock released on core %u - count = %d\n",
  90                id, slr.count);
  91         rte_spinlock_recursive_unlock(&slr);
  92         printf("Global recursive lock released on core %u - count = %d\n",
  93                id, slr.count);
  94
  95         return 0;
  96 }
  97
  98 static rte_spinlock_t lk = RTE_SPINLOCK_INITIALIZER;
  99 static uint64_t time_count[RTE_MAX_LCORE] = {0};
 100
 101 #define MAX_LOOP 10000
 102
 103 static int
 104 load_loop_fn(void *func_param)
 105 {
 106         uint64_t time_diff = 0, begin;
 107         uint64_t hz = rte_get_timer_hz();
 108         volatile uint64_t lcount = 0;
 109         const int use_lock = *(int*)func_param;
 110         const unsigned lcore = rte_lcore_id();
 111
 112         /* wait synchro for slaves */
 113         if (lcore != rte_get_master_lcore())
 114                 while (rte_atomic32_read(&synchro) == 0);
 115
 116         begin = rte_get_timer_cycles();
 117         while (lcount < MAX_LOOP) {
 118                 if (use_lock)
 119                         rte_spinlock_lock(&lk);
 120                 lcount++;
 121                 if (use_lock)
 122                         rte_spinlock_unlock(&lk);
 123         }
 124         time_diff = rte_get_timer_cycles() - begin;
 125         time_count[lcore] = time_diff * 1000000 / hz;
 126         return 0;
 127 }
 128
 129 static int
 130 test_spinlock_perf(void)
 131 {
 132         unsigned int i;
 133         uint64_t total = 0;
 134         int lock = 0;
 135         const unsigned lcore = rte_lcore_id();
 136
 137         printf("\nTest with no lock on single core...\n");
 138         load_loop_fn(&lock);
 139         printf("Core [%u] Cost Time = %"PRIu64" us\n", lcore,
 140                                                 time_count[lcore]);
 141         memset(time_count, 0, sizeof(time_count));
 142
 143         printf("\nTest with lock on single core...\n");
 144         lock = 1;
 145         load_loop_fn(&lock);
 146         printf("Core [%u] Cost Time = %"PRIu64" us\n", lcore,
 147                                                 time_count[lcore]);
 148         memset(time_count, 0, sizeof(time_count));
 149
 150         printf("\nTest with lock on %u cores...\n", rte_lcore_count());
 151
 152         /* Clear synchro and start slaves */
 153         rte_atomic32_set(&synchro, 0);
 154         rte_eal_mp_remote_launch(load_loop_fn, &lock, SKIP_MASTER);
 155
 156         /* start synchro and launch test on master */
 157         rte_atomic32_set(&synchro, 1);
 158         load_loop_fn(&lock);
 159
 160         rte_eal_mp_wait_lcore();
 161
 162         RTE_LCORE_FOREACH(i) {
 163                 printf("Core [%u] Cost Time = %"PRIu64" us\n", i,
 164                                                 time_count[i]);
 165                 total += time_count[i];
 166         }
 167
 168         printf("Total Cost Time = %"PRIu64" us\n", total);
 169
 170         return 0;
 171 }
 172
 173 /*
 174  * Use rte_spinlock_trylock() to trylock a spinlock object,
 175  * If it could not lock the object successfully, it would
 176  * return immediately and the variable of "count" would be
 177  * increased by one per times. the value of "count" could be
 178  * checked as the result later.
 179  */
 180 static int
 181 test_spinlock_try(__attribute__((unused)) void *arg)
 182 {
 183         if (rte_spinlock_trylock(&sl_try) == 0) {
 184                 rte_spinlock_lock(&sl);
 185                 count ++;
 186                 rte_spinlock_unlock(&sl);
 187         }
 188
 189         return 0;
 190 }
 191
 192
 193 /*
 194  * Test rte_eal_get_lcore_state() in addition to spinlocks
 195  * as we have "waiting" then "running" lcores.
 196  */
 197 static int
 198 test_spinlock(void)
 199 {
 200         int ret = 0;
 201         int i;
 202
 203         /* slave cores should be waiting: print it */
 204         RTE_LCORE_FOREACH_SLAVE(i) {
 205                 printf("lcore %d state: %d\n", i,
 206                        (int) rte_eal_get_lcore_state(i));
 207         }
 208
 209         rte_spinlock_init(&sl);
 210         rte_spinlock_init(&sl_try);
 211         rte_spinlock_recursive_init(&slr);
 212         for (i=0; i<RTE_MAX_LCORE; i++)
 213                 rte_spinlock_init(&sl_tab[i]);
 214
 215         rte_spinlock_lock(&sl);
 216
 217         RTE_LCORE_FOREACH_SLAVE(i) {
 218                 rte_spinlock_lock(&sl_tab[i]);
 219                 rte_eal_remote_launch(test_spinlock_per_core, NULL, i);
 220         }
 221
 222         /* slave cores should be busy: print it */
 223         RTE_LCORE_FOREACH_SLAVE(i) {
 224                 printf("lcore %d state: %d\n", i,
 225                        (int) rte_eal_get_lcore_state(i));
 226         }
 227         rte_spinlock_unlock(&sl);
 228
 229         RTE_LCORE_FOREACH_SLAVE(i) {
 230                 rte_spinlock_unlock(&sl_tab[i]);
 231                 rte_delay_ms(10);
 232         }
 233
 234         rte_eal_mp_wait_lcore();
 235
 236         rte_spinlock_recursive_lock(&slr);
 237
 238         /*
 239          * Try to acquire a lock that we already own
 240          */
 241         if(!rte_spinlock_recursive_trylock(&slr)) {
 242                 printf("rte_spinlock_recursive_trylock failed on a lock that "
 243                        "we already own\n");
 244                 ret = -1;
 245         } else
 246                 rte_spinlock_recursive_unlock(&slr);
 247
 248         RTE_LCORE_FOREACH_SLAVE(i) {
 249                 rte_eal_remote_launch(test_spinlock_recursive_per_core, NULL, i);
 250         }
 251         rte_spinlock_recursive_unlock(&slr);
 252         rte_eal_mp_wait_lcore();
 253
 254         /*
 255          * Test if it could return immediately from try-locking a locked object.
 256          * Here it will lock the spinlock object first, then launch all the slave
 257          * lcores to trylock the same spinlock object.
 258          * All the slave lcores should give up try-locking a locked object and
 259          * return immediately, and then increase the "count" initialized with zero
 260          * by one per times.
 261          * We can check if the "count" is finally equal to the number of all slave
 262          * lcores to see if the behavior of try-locking a locked spinlock object
 263          * is correct.
 264          */
 265         if (rte_spinlock_trylock(&sl_try) == 0) {
 266                 return -1;
 267         }
 268         count = 0;
 269         RTE_LCORE_FOREACH_SLAVE(i) {
 270                 rte_eal_remote_launch(test_spinlock_try, NULL, i);
 271         }
 272         rte_eal_mp_wait_lcore();
 273         rte_spinlock_unlock(&sl_try);
 274         if (rte_spinlock_is_locked(&sl)) {
 275                 printf("spinlock is locked but it should not be\n");
 276                 return -1;
 277         }
 278         rte_spinlock_lock(&sl);
 279         if (count != ( rte_lcore_count() - 1)) {
 280                 ret = -1;
 281         }
 282         rte_spinlock_unlock(&sl);
 283
 284         /*
 285          * Test if it can trylock recursively.
 286          * Use rte_spinlock_recursive_trylock() to check if it can lock a spinlock
 287          * object recursively. Here it will try to lock a spinlock object twice.
 288          */
 289         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 290                 printf("It failed to do the first spinlock_recursive_trylock but it should able to do\n");
 291                 return -1;
 292         }
 293         if (rte_spinlock_recursive_trylock(&slr) == 0) {
 294                 printf("It failed to do the second spinlock_recursive_trylock but it should able to do\n");
 295                 return -1;
 296         }
 297         rte_spinlock_recursive_unlock(&slr);
 298         rte_spinlock_recursive_unlock(&slr);
 299
 300         if (test_spinlock_perf() < 0)
 301                 return -1;
 302
 303         return ret;
 304 }
 305
 306 REGISTER_TEST_COMMAND(spinlock_autotest, test_spinlock);