lib/test_vmalloc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Test module for stress and analyze performance of vmalloc allocator.
   5  * (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com>
   6  */
   7 #include <linux/init.h>
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/vmalloc.h>
  11 #include <linux/random.h>
  12 #include <linux/kthread.h>
  13 #include <linux/moduleparam.h>
  14 #include <linux/completion.h>
  15 #include <linux/delay.h>
  16 #include <linux/rwsem.h>
  17 #include <linux/mm.h>
  18
  19 #define __param(type, name, init, msg)          \
  20         static type name = init;                                \
  21         module_param(name, type, 0444);                 \
  22         MODULE_PARM_DESC(name, msg)                             \
  23
  24 __param(bool, single_cpu_test, false,
  25         "Use single first online CPU to run tests");
  26
  27 __param(bool, sequential_test_order, false,
  28         "Use sequential stress tests order");
  29
  30 __param(int, test_repeat_count, 1,
  31         "Set test repeat counter");
  32
  33 __param(int, test_loop_count, 1000000,
  34         "Set test loop counter");
  35
  36 __param(int, run_test_mask, INT_MAX,
  37         "Set tests specified in the mask.\n\n"
  38                 "\t\tid: 1,   name: fix_size_alloc_test\n"
  39                 "\t\tid: 2,   name: full_fit_alloc_test\n"
  40                 "\t\tid: 4,   name: long_busy_list_alloc_test\n"
  41                 "\t\tid: 8,   name: random_size_alloc_test\n"
  42                 "\t\tid: 16,  name: fix_align_alloc_test\n"
  43                 "\t\tid: 32,  name: random_size_align_alloc_test\n"
  44                 "\t\tid: 64,  name: align_shift_alloc_test\n"
  45                 "\t\tid: 128, name: pcpu_alloc_test\n"
  46                 /* Add a new test case description here. */
  47 );
  48
  49 /*
  50  * Depends on single_cpu_test parameter. If it is true, then
  51  * use first online CPU to trigger a test on, otherwise go with
  52  * all online CPUs.
  53  */
  54 static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
  55
  56 /*
  57  * Read write semaphore for synchronization of setup
  58  * phase that is done in main thread and workers.
  59  */
  60 static DECLARE_RWSEM(prepare_for_test_rwsem);
  61
  62 /*
  63  * Completion tracking for worker threads.
  64  */
  65 static DECLARE_COMPLETION(test_all_done_comp);
  66 static atomic_t test_n_undone = ATOMIC_INIT(0);
  67
  68 static inline void
  69 test_report_one_done(void)
  70 {
  71         if (atomic_dec_and_test(&test_n_undone))
  72                 complete(&test_all_done_comp);
  73 }
  74
  75 static int random_size_align_alloc_test(void)
  76 {
  77         unsigned long size, align, rnd;
  78         void *ptr;
  79         int i;
  80
  81         for (i = 0; i < test_loop_count; i++) {
  82                 get_random_bytes(&rnd, sizeof(rnd));
  83
  84                 /*
  85                  * Maximum 1024 pages, if PAGE_SIZE is 4096.
  86                  */
  87                 align = 1 << (rnd % 23);
  88
  89                 /*
  90                  * Maximum 10 pages.
  91                  */
  92                 size = ((rnd % 10) + 1) * PAGE_SIZE;
  93
  94                 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
  95                                 __builtin_return_address(0));
  96                 if (!ptr)
  97                         return -1;
  98
  99                 vfree(ptr);
 100         }
 101
 102         return 0;
 103 }
 104
 105 /*
 106  * This test case is supposed to be failed.
 107  */
 108 static int align_shift_alloc_test(void)
 109 {
 110         unsigned long align;
 111         void *ptr;
 112         int i;
 113
 114         for (i = 0; i < BITS_PER_LONG; i++) {
 115                 align = ((unsigned long) 1) << i;
 116
 117                 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
 118                                 __builtin_return_address(0));
 119                 if (!ptr)
 120                         return -1;
 121
 122                 vfree(ptr);
 123         }
 124
 125         return 0;
 126 }
 127
 128 static int fix_align_alloc_test(void)
 129 {
 130         void *ptr;
 131         int i;
 132
 133         for (i = 0; i < test_loop_count; i++) {
 134                 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
 135                                 GFP_KERNEL | __GFP_ZERO, 0,
 136                                 __builtin_return_address(0));
 137                 if (!ptr)
 138                         return -1;
 139
 140                 vfree(ptr);
 141         }
 142
 143         return 0;
 144 }
 145
 146 static int random_size_alloc_test(void)
 147 {
 148         unsigned int n;
 149         void *p;
 150         int i;
 151
 152         for (i = 0; i < test_loop_count; i++) {
 153                 get_random_bytes(&n, sizeof(i));
 154                 n = (n % 100) + 1;
 155
 156                 p = vmalloc(n * PAGE_SIZE);
 157
 158                 if (!p)
 159                         return -1;
 160
 161                 *((__u8 *)p) = 1;
 162                 vfree(p);
 163         }
 164
 165         return 0;
 166 }
 167
 168 static int long_busy_list_alloc_test(void)
 169 {
 170         void *ptr_1, *ptr_2;
 171         void **ptr;
 172         int rv = -1;
 173         int i;
 174
 175         ptr = vmalloc(sizeof(void *) * 15000);
 176         if (!ptr)
 177                 return rv;
 178
 179         for (i = 0; i < 15000; i++)
 180                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 181
 182         for (i = 0; i < test_loop_count; i++) {
 183                 ptr_1 = vmalloc(100 * PAGE_SIZE);
 184                 if (!ptr_1)
 185                         goto leave;
 186
 187                 ptr_2 = vmalloc(1 * PAGE_SIZE);
 188                 if (!ptr_2) {
 189                         vfree(ptr_1);
 190                         goto leave;
 191                 }
 192
 193                 *((__u8 *)ptr_1) = 0;
 194                 *((__u8 *)ptr_2) = 1;
 195
 196                 vfree(ptr_1);
 197                 vfree(ptr_2);
 198         }
 199
 200         /*  Success */
 201         rv = 0;
 202
 203 leave:
 204         for (i = 0; i < 15000; i++)
 205                 vfree(ptr[i]);
 206
 207         vfree(ptr);
 208         return rv;
 209 }
 210
 211 static int full_fit_alloc_test(void)
 212 {
 213         void **ptr, **junk_ptr, *tmp;
 214         int junk_length;
 215         int rv = -1;
 216         int i;
 217
 218         junk_length = fls(num_online_cpus());
 219         junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
 220
 221         ptr = vmalloc(sizeof(void *) * junk_length);
 222         if (!ptr)
 223                 return rv;
 224
 225         junk_ptr = vmalloc(sizeof(void *) * junk_length);
 226         if (!junk_ptr) {
 227                 vfree(ptr);
 228                 return rv;
 229         }
 230
 231         for (i = 0; i < junk_length; i++) {
 232                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 233                 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
 234         }
 235
 236         for (i = 0; i < junk_length; i++)
 237                 vfree(junk_ptr[i]);
 238
 239         for (i = 0; i < test_loop_count; i++) {
 240                 tmp = vmalloc(1 * PAGE_SIZE);
 241
 242                 if (!tmp)
 243                         goto error;
 244
 245                 *((__u8 *)tmp) = 1;
 246                 vfree(tmp);
 247         }
 248
 249         /* Success */
 250         rv = 0;
 251
 252 error:
 253         for (i = 0; i < junk_length; i++)
 254                 vfree(ptr[i]);
 255
 256         vfree(ptr);
 257         vfree(junk_ptr);
 258
 259         return rv;
 260 }
 261
 262 static int fix_size_alloc_test(void)
 263 {
 264         void *ptr;
 265         int i;
 266
 267         for (i = 0; i < test_loop_count; i++) {
 268                 ptr = vmalloc(3 * PAGE_SIZE);
 269
 270                 if (!ptr)
 271                         return -1;
 272
 273                 *((__u8 *)ptr) = 0;
 274
 275                 vfree(ptr);
 276         }
 277
 278         return 0;
 279 }
 280
 281 static int
 282 pcpu_alloc_test(void)
 283 {
 284         int rv = 0;
 285 #ifndef CONFIG_NEED_PER_CPU_KM
 286         void __percpu **pcpu;
 287         size_t size, align;
 288         int i;
 289
 290         pcpu = vmalloc(sizeof(void __percpu *) * 35000);
 291         if (!pcpu)
 292                 return -1;
 293
 294         for (i = 0; i < 35000; i++) {
 295                 unsigned int r;
 296
 297                 get_random_bytes(&r, sizeof(i));
 298                 size = (r % (PAGE_SIZE / 4)) + 1;
 299
 300                 /*
 301                  * Maximum PAGE_SIZE
 302                  */
 303                 get_random_bytes(&r, sizeof(i));
 304                 align = 1 << ((i % 11) + 1);
 305
 306                 pcpu[i] = __alloc_percpu(size, align);
 307                 if (!pcpu[i])
 308                         rv = -1;
 309         }
 310
 311         for (i = 0; i < 35000; i++)
 312                 free_percpu(pcpu[i]);
 313
 314         vfree(pcpu);
 315 #endif
 316         return rv;
 317 }
 318
 319 struct test_case_desc {
 320         const char *test_name;
 321         int (*test_func)(void);
 322 };
 323
 324 static struct test_case_desc test_case_array[] = {
 325         { "fix_size_alloc_test", fix_size_alloc_test },
 326         { "full_fit_alloc_test", full_fit_alloc_test },
 327         { "long_busy_list_alloc_test", long_busy_list_alloc_test },
 328         { "random_size_alloc_test", random_size_alloc_test },
 329         { "fix_align_alloc_test", fix_align_alloc_test },
 330         { "random_size_align_alloc_test", random_size_align_alloc_test },
 331         { "align_shift_alloc_test", align_shift_alloc_test },
 332         { "pcpu_alloc_test", pcpu_alloc_test },
 333         /* Add a new test case here. */
 334 };
 335
 336 struct test_case_data {
 337         int test_failed;
 338         int test_passed;
 339         u64 time;
 340 };
 341
 342 /* Split it to get rid of: WARNING: line over 80 characters */
 343 static struct test_case_data
 344         per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
 345
 346 static struct test_driver {
 347         struct task_struct *task;
 348         unsigned long start;
 349         unsigned long stop;
 350         int cpu;
 351 } per_cpu_test_driver[NR_CPUS];
 352
 353 static void shuffle_array(int *arr, int n)
 354 {
 355         unsigned int rnd;
 356         int i, j, x;
 357
 358         for (i = n - 1; i > 0; i--)  {
 359                 get_random_bytes(&rnd, sizeof(rnd));
 360
 361                 /* Cut the range. */
 362                 j = rnd % i;
 363
 364                 /* Swap indexes. */
 365                 x = arr[i];
 366                 arr[i] = arr[j];
 367                 arr[j] = x;
 368         }
 369 }
 370
 371 static int test_func(void *private)
 372 {
 373         struct test_driver *t = private;
 374         int random_array[ARRAY_SIZE(test_case_array)];
 375         int index, i, j;
 376         ktime_t kt;
 377         u64 delta;
 378
 379         if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
 380                 pr_err("Failed to set affinity to %d CPU\n", t->cpu);
 381
 382         for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
 383                 random_array[i] = i;
 384
 385         if (!sequential_test_order)
 386                 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
 387
 388         /*
 389          * Block until initialization is done.
 390          */
 391         down_read(&prepare_for_test_rwsem);
 392
 393         t->start = get_cycles();
 394         for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 395                 index = random_array[i];
 396
 397                 /*
 398                  * Skip tests if run_test_mask has been specified.
 399                  */
 400                 if (!((run_test_mask & (1 << index)) >> index))
 401                         continue;
 402
 403                 kt = ktime_get();
 404                 for (j = 0; j < test_repeat_count; j++) {
 405                         if (!test_case_array[index].test_func())
 406                                 per_cpu_test_data[t->cpu][index].test_passed++;
 407                         else
 408                                 per_cpu_test_data[t->cpu][index].test_failed++;
 409                 }
 410
 411                 /*
 412                  * Take an average time that test took.
 413                  */
 414                 delta = (u64) ktime_us_delta(ktime_get(), kt);
 415                 do_div(delta, (u32) test_repeat_count);
 416
 417                 per_cpu_test_data[t->cpu][index].time = delta;
 418         }
 419         t->stop = get_cycles();
 420
 421         up_read(&prepare_for_test_rwsem);
 422         test_report_one_done();
 423
 424         /*
 425          * Wait for the kthread_stop() call.
 426          */
 427         while (!kthread_should_stop())
 428                 msleep(10);
 429
 430         return 0;
 431 }
 432
 433 static void
 434 init_test_configurtion(void)
 435 {
 436         /*
 437          * Reset all data of all CPUs.
 438          */
 439         memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
 440
 441         if (single_cpu_test)
 442                 cpumask_set_cpu(cpumask_first(cpu_online_mask),
 443                         &cpus_run_test_mask);
 444         else
 445                 cpumask_and(&cpus_run_test_mask, cpu_online_mask,
 446                         cpu_online_mask);
 447
 448         if (test_repeat_count <= 0)
 449                 test_repeat_count = 1;
 450
 451         if (test_loop_count <= 0)
 452                 test_loop_count = 1;
 453 }
 454
 455 static void do_concurrent_test(void)
 456 {
 457         int cpu, ret;
 458
 459         /*
 460          * Set some basic configurations plus sanity check.
 461          */
 462         init_test_configurtion();
 463
 464         /*
 465          * Put on hold all workers.
 466          */
 467         down_write(&prepare_for_test_rwsem);
 468
 469         for_each_cpu(cpu, &cpus_run_test_mask) {
 470                 struct test_driver *t = &per_cpu_test_driver[cpu];
 471
 472                 t->cpu = cpu;
 473                 t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
 474
 475                 if (!IS_ERR(t->task))
 476                         /* Success. */
 477                         atomic_inc(&test_n_undone);
 478                 else
 479                         pr_err("Failed to start kthread for %d CPU\n", cpu);
 480         }
 481
 482         /*
 483          * Now let the workers do their job.
 484          */
 485         up_write(&prepare_for_test_rwsem);
 486
 487         /*
 488          * Sleep quiet until all workers are done with 1 second
 489          * interval. Since the test can take a lot of time we
 490          * can run into a stack trace of the hung task. That is
 491          * why we go with completion_timeout and HZ value.
 492          */
 493         do {
 494                 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
 495         } while (!ret);
 496
 497         for_each_cpu(cpu, &cpus_run_test_mask) {
 498                 struct test_driver *t = &per_cpu_test_driver[cpu];
 499                 int i;
 500
 501                 if (!IS_ERR(t->task))
 502                         kthread_stop(t->task);
 503
 504                 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 505                         if (!((run_test_mask & (1 << i)) >> i))
 506                                 continue;
 507
 508                         pr_info(
 509                                 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
 510                                 test_case_array[i].test_name,
 511                                 per_cpu_test_data[cpu][i].test_passed,
 512                                 per_cpu_test_data[cpu][i].test_failed,
 513                                 test_repeat_count, test_loop_count,
 514                                 per_cpu_test_data[cpu][i].time);
 515                 }
 516
 517                 pr_info("All test took CPU%d=%lu cycles\n",
 518                         cpu, t->stop - t->start);
 519         }
 520 }
 521
 522 static int vmalloc_test_init(void)
 523 {
 524         do_concurrent_test();
 525         return -EAGAIN; /* Fail will directly unload the module */
 526 }
 527
 528 static void vmalloc_test_exit(void)
 529 {
 530 }
 531
 532 module_init(vmalloc_test_init)
 533 module_exit(vmalloc_test_exit)
 534
 535 MODULE_LICENSE("GPL");
 536 MODULE_AUTHOR("Uladzislau Rezki");
 537 MODULE_DESCRIPTION("vmalloc test module");