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 #include <linux/rcupdate.h>
  19 #include <linux/slab.h>
  20
  21 #define __param(type, name, init, msg)          \
  22         static type name = init;                                \
  23         module_param(name, type, 0444);                 \
  24         MODULE_PARM_DESC(name, msg)                             \
  25
  26 __param(int, nr_threads, 0,
  27         "Number of workers to perform tests(min: 1 max: USHRT_MAX)");
  28
  29 __param(bool, sequential_test_order, false,
  30         "Use sequential stress tests order");
  31
  32 __param(int, test_repeat_count, 1,
  33         "Set test repeat counter");
  34
  35 __param(int, test_loop_count, 1000000,
  36         "Set test loop counter");
  37
  38 __param(int, nr_pages, 0,
  39         "Set number of pages for fix_size_alloc_test(default: 1)");
  40
  41 __param(bool, use_huge, false,
  42         "Use vmalloc_huge in fix_size_alloc_test");
  43
  44 __param(int, run_test_mask, INT_MAX,
  45         "Set tests specified in the mask.\n\n"
  46                 "\t\tid: 1,    name: fix_size_alloc_test\n"
  47                 "\t\tid: 2,    name: full_fit_alloc_test\n"
  48                 "\t\tid: 4,    name: long_busy_list_alloc_test\n"
  49                 "\t\tid: 8,    name: random_size_alloc_test\n"
  50                 "\t\tid: 16,   name: fix_align_alloc_test\n"
  51                 "\t\tid: 32,   name: random_size_align_alloc_test\n"
  52                 "\t\tid: 64,   name: align_shift_alloc_test\n"
  53                 "\t\tid: 128,  name: pcpu_alloc_test\n"
  54                 "\t\tid: 256,  name: kvfree_rcu_1_arg_vmalloc_test\n"
  55                 "\t\tid: 512,  name: kvfree_rcu_2_arg_vmalloc_test\n"
  56                 "\t\tid: 1024, name: vm_map_ram_test\n"
  57                 /* Add a new test case description here. */
  58 );
  59
  60 /*
  61  * Read write semaphore for synchronization of setup
  62  * phase that is done in main thread and workers.
  63  */
  64 static DECLARE_RWSEM(prepare_for_test_rwsem);
  65
  66 /*
  67  * Completion tracking for worker threads.
  68  */
  69 static DECLARE_COMPLETION(test_all_done_comp);
  70 static atomic_t test_n_undone = ATOMIC_INIT(0);
  71
  72 static inline void
  73 test_report_one_done(void)
  74 {
  75         if (atomic_dec_and_test(&test_n_undone))
  76                 complete(&test_all_done_comp);
  77 }
  78
  79 static int random_size_align_alloc_test(void)
  80 {
  81         unsigned long size, align;
  82         unsigned int rnd;
  83         void *ptr;
  84         int i;
  85
  86         for (i = 0; i < test_loop_count; i++) {
  87                 rnd = get_random_u8();
  88
  89                 /*
  90                  * Maximum 1024 pages, if PAGE_SIZE is 4096.
  91                  */
  92                 align = 1 << (rnd % 23);
  93
  94                 /*
  95                  * Maximum 10 pages.
  96                  */
  97                 size = ((rnd % 10) + 1) * PAGE_SIZE;
  98
  99                 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
 100                                 __builtin_return_address(0));
 101                 if (!ptr)
 102                         return -1;
 103
 104                 vfree(ptr);
 105         }
 106
 107         return 0;
 108 }
 109
 110 /*
 111  * This test case is supposed to be failed.
 112  */
 113 static int align_shift_alloc_test(void)
 114 {
 115         unsigned long align;
 116         void *ptr;
 117         int i;
 118
 119         for (i = 0; i < BITS_PER_LONG; i++) {
 120                 align = 1UL << i;
 121
 122                 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
 123                                 __builtin_return_address(0));
 124                 if (!ptr)
 125                         return -1;
 126
 127                 vfree(ptr);
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int fix_align_alloc_test(void)
 134 {
 135         void *ptr;
 136         int i;
 137
 138         for (i = 0; i < test_loop_count; i++) {
 139                 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
 140                                 GFP_KERNEL | __GFP_ZERO, 0,
 141                                 __builtin_return_address(0));
 142                 if (!ptr)
 143                         return -1;
 144
 145                 vfree(ptr);
 146         }
 147
 148         return 0;
 149 }
 150
 151 static int random_size_alloc_test(void)
 152 {
 153         unsigned int n;
 154         void *p;
 155         int i;
 156
 157         for (i = 0; i < test_loop_count; i++) {
 158                 n = get_random_u32_inclusive(1, 100);
 159                 p = vmalloc(n * PAGE_SIZE);
 160
 161                 if (!p)
 162                         return -1;
 163
 164                 *((__u8 *)p) = 1;
 165                 vfree(p);
 166         }
 167
 168         return 0;
 169 }
 170
 171 static int long_busy_list_alloc_test(void)
 172 {
 173         void *ptr_1, *ptr_2;
 174         void **ptr;
 175         int rv = -1;
 176         int i;
 177
 178         ptr = vmalloc(sizeof(void *) * 15000);
 179         if (!ptr)
 180                 return rv;
 181
 182         for (i = 0; i < 15000; i++)
 183                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 184
 185         for (i = 0; i < test_loop_count; i++) {
 186                 ptr_1 = vmalloc(100 * PAGE_SIZE);
 187                 if (!ptr_1)
 188                         goto leave;
 189
 190                 ptr_2 = vmalloc(1 * PAGE_SIZE);
 191                 if (!ptr_2) {
 192                         vfree(ptr_1);
 193                         goto leave;
 194                 }
 195
 196                 *((__u8 *)ptr_1) = 0;
 197                 *((__u8 *)ptr_2) = 1;
 198
 199                 vfree(ptr_1);
 200                 vfree(ptr_2);
 201         }
 202
 203         /*  Success */
 204         rv = 0;
 205
 206 leave:
 207         for (i = 0; i < 15000; i++)
 208                 vfree(ptr[i]);
 209
 210         vfree(ptr);
 211         return rv;
 212 }
 213
 214 static int full_fit_alloc_test(void)
 215 {
 216         void **ptr, **junk_ptr, *tmp;
 217         int junk_length;
 218         int rv = -1;
 219         int i;
 220
 221         junk_length = fls(num_online_cpus());
 222         junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
 223
 224         ptr = vmalloc(sizeof(void *) * junk_length);
 225         if (!ptr)
 226                 return rv;
 227
 228         junk_ptr = vmalloc(sizeof(void *) * junk_length);
 229         if (!junk_ptr) {
 230                 vfree(ptr);
 231                 return rv;
 232         }
 233
 234         for (i = 0; i < junk_length; i++) {
 235                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 236                 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
 237         }
 238
 239         for (i = 0; i < junk_length; i++)
 240                 vfree(junk_ptr[i]);
 241
 242         for (i = 0; i < test_loop_count; i++) {
 243                 tmp = vmalloc(1 * PAGE_SIZE);
 244
 245                 if (!tmp)
 246                         goto error;
 247
 248                 *((__u8 *)tmp) = 1;
 249                 vfree(tmp);
 250         }
 251
 252         /* Success */
 253         rv = 0;
 254
 255 error:
 256         for (i = 0; i < junk_length; i++)
 257                 vfree(ptr[i]);
 258
 259         vfree(ptr);
 260         vfree(junk_ptr);
 261
 262         return rv;
 263 }
 264
 265 static int fix_size_alloc_test(void)
 266 {
 267         void *ptr;
 268         int i;
 269
 270         for (i = 0; i < test_loop_count; i++) {
 271                 if (use_huge)
 272                         ptr = vmalloc_huge((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE, GFP_KERNEL);
 273                 else
 274                         ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
 275
 276                 if (!ptr)
 277                         return -1;
 278
 279                 *((__u8 *)ptr) = 0;
 280
 281                 vfree(ptr);
 282         }
 283
 284         return 0;
 285 }
 286
 287 static int
 288 pcpu_alloc_test(void)
 289 {
 290         int rv = 0;
 291 #ifndef CONFIG_NEED_PER_CPU_KM
 292         void __percpu **pcpu;
 293         size_t size, align;
 294         int i;
 295
 296         pcpu = vmalloc(sizeof(void __percpu *) * 35000);
 297         if (!pcpu)
 298                 return -1;
 299
 300         for (i = 0; i < 35000; i++) {
 301                 size = get_random_u32_inclusive(1, PAGE_SIZE / 4);
 302
 303                 /*
 304                  * Maximum PAGE_SIZE
 305                  */
 306                 align = 1 << get_random_u32_inclusive(1, 11);
 307
 308                 pcpu[i] = __alloc_percpu(size, align);
 309                 if (!pcpu[i])
 310                         rv = -1;
 311         }
 312
 313         for (i = 0; i < 35000; i++)
 314                 free_percpu(pcpu[i]);
 315
 316         vfree(pcpu);
 317 #endif
 318         return rv;
 319 }
 320
 321 struct test_kvfree_rcu {
 322         struct rcu_head rcu;
 323         unsigned char array[20];
 324 };
 325
 326 static int
 327 kvfree_rcu_1_arg_vmalloc_test(void)
 328 {
 329         struct test_kvfree_rcu *p;
 330         int i;
 331
 332         for (i = 0; i < test_loop_count; i++) {
 333                 p = vmalloc(1 * PAGE_SIZE);
 334                 if (!p)
 335                         return -1;
 336
 337                 p->array[0] = 'a';
 338                 kvfree_rcu_mightsleep(p);
 339         }
 340
 341         return 0;
 342 }
 343
 344 static int
 345 kvfree_rcu_2_arg_vmalloc_test(void)
 346 {
 347         struct test_kvfree_rcu *p;
 348         int i;
 349
 350         for (i = 0; i < test_loop_count; i++) {
 351                 p = vmalloc(1 * PAGE_SIZE);
 352                 if (!p)
 353                         return -1;
 354
 355                 p->array[0] = 'a';
 356                 kvfree_rcu(p, rcu);
 357         }
 358
 359         return 0;
 360 }
 361
 362 static int
 363 vm_map_ram_test(void)
 364 {
 365         unsigned long nr_allocated;
 366         unsigned int map_nr_pages;
 367         unsigned char *v_ptr;
 368         struct page **pages;
 369         int i;
 370
 371         map_nr_pages = nr_pages > 0 ? nr_pages:1;
 372         pages = kcalloc(map_nr_pages, sizeof(struct page *), GFP_KERNEL);
 373         if (!pages)
 374                 return -1;
 375
 376         nr_allocated = alloc_pages_bulk_array(GFP_KERNEL, map_nr_pages, pages);
 377         if (nr_allocated != map_nr_pages)
 378                 goto cleanup;
 379
 380         /* Run the test loop. */
 381         for (i = 0; i < test_loop_count; i++) {
 382                 v_ptr = vm_map_ram(pages, map_nr_pages, NUMA_NO_NODE);
 383                 *v_ptr = 'a';
 384                 vm_unmap_ram(v_ptr, map_nr_pages);
 385         }
 386
 387 cleanup:
 388         for (i = 0; i < nr_allocated; i++)
 389                 __free_page(pages[i]);
 390
 391         kfree(pages);
 392
 393         /* 0 indicates success. */
 394         return nr_allocated != map_nr_pages;
 395 }
 396
 397 struct test_case_desc {
 398         const char *test_name;
 399         int (*test_func)(void);
 400 };
 401
 402 static struct test_case_desc test_case_array[] = {
 403         { "fix_size_alloc_test", fix_size_alloc_test },
 404         { "full_fit_alloc_test", full_fit_alloc_test },
 405         { "long_busy_list_alloc_test", long_busy_list_alloc_test },
 406         { "random_size_alloc_test", random_size_alloc_test },
 407         { "fix_align_alloc_test", fix_align_alloc_test },
 408         { "random_size_align_alloc_test", random_size_align_alloc_test },
 409         { "align_shift_alloc_test", align_shift_alloc_test },
 410         { "pcpu_alloc_test", pcpu_alloc_test },
 411         { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
 412         { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
 413         { "vm_map_ram_test", vm_map_ram_test },
 414         /* Add a new test case here. */
 415 };
 416
 417 struct test_case_data {
 418         int test_failed;
 419         int test_passed;
 420         u64 time;
 421 };
 422
 423 static struct test_driver {
 424         struct task_struct *task;
 425         struct test_case_data data[ARRAY_SIZE(test_case_array)];
 426
 427         unsigned long start;
 428         unsigned long stop;
 429 } *tdriver;
 430
 431 static void shuffle_array(int *arr, int n)
 432 {
 433         int i, j;
 434
 435         for (i = n - 1; i > 0; i--)  {
 436                 /* Cut the range. */
 437                 j = get_random_u32_below(i);
 438
 439                 /* Swap indexes. */
 440                 swap(arr[i], arr[j]);
 441         }
 442 }
 443
 444 static int test_func(void *private)
 445 {
 446         struct test_driver *t = private;
 447         int random_array[ARRAY_SIZE(test_case_array)];
 448         int index, i, j;
 449         ktime_t kt;
 450         u64 delta;
 451
 452         for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
 453                 random_array[i] = i;
 454
 455         if (!sequential_test_order)
 456                 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
 457
 458         /*
 459          * Block until initialization is done.
 460          */
 461         down_read(&prepare_for_test_rwsem);
 462
 463         t->start = get_cycles();
 464         for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 465                 index = random_array[i];
 466
 467                 /*
 468                  * Skip tests if run_test_mask has been specified.
 469                  */
 470                 if (!((run_test_mask & (1 << index)) >> index))
 471                         continue;
 472
 473                 kt = ktime_get();
 474                 for (j = 0; j < test_repeat_count; j++) {
 475                         if (!test_case_array[index].test_func())
 476                                 t->data[index].test_passed++;
 477                         else
 478                                 t->data[index].test_failed++;
 479                 }
 480
 481                 /*
 482                  * Take an average time that test took.
 483                  */
 484                 delta = (u64) ktime_us_delta(ktime_get(), kt);
 485                 do_div(delta, (u32) test_repeat_count);
 486
 487                 t->data[index].time = delta;
 488         }
 489         t->stop = get_cycles();
 490
 491         up_read(&prepare_for_test_rwsem);
 492         test_report_one_done();
 493
 494         /*
 495          * Wait for the kthread_stop() call.
 496          */
 497         while (!kthread_should_stop())
 498                 msleep(10);
 499
 500         return 0;
 501 }
 502
 503 static int
 504 init_test_configuration(void)
 505 {
 506         /*
 507          * A maximum number of workers is defined as hard-coded
 508          * value and set to USHRT_MAX. We add such gap just in
 509          * case and for potential heavy stressing.
 510          */
 511         nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
 512
 513         /* Allocate the space for test instances. */
 514         tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
 515         if (tdriver == NULL)
 516                 return -1;
 517
 518         if (test_repeat_count <= 0)
 519                 test_repeat_count = 1;
 520
 521         if (test_loop_count <= 0)
 522                 test_loop_count = 1;
 523
 524         return 0;
 525 }
 526
 527 static void do_concurrent_test(void)
 528 {
 529         int i, ret;
 530
 531         /*
 532          * Set some basic configurations plus sanity check.
 533          */
 534         ret = init_test_configuration();
 535         if (ret < 0)
 536                 return;
 537
 538         /*
 539          * Put on hold all workers.
 540          */
 541         down_write(&prepare_for_test_rwsem);
 542
 543         for (i = 0; i < nr_threads; i++) {
 544                 struct test_driver *t = &tdriver[i];
 545
 546                 t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
 547
 548                 if (!IS_ERR(t->task))
 549                         /* Success. */
 550                         atomic_inc(&test_n_undone);
 551                 else
 552                         pr_err("Failed to start %d kthread\n", i);
 553         }
 554
 555         /*
 556          * Now let the workers do their job.
 557          */
 558         up_write(&prepare_for_test_rwsem);
 559
 560         /*
 561          * Sleep quiet until all workers are done with 1 second
 562          * interval. Since the test can take a lot of time we
 563          * can run into a stack trace of the hung task. That is
 564          * why we go with completion_timeout and HZ value.
 565          */
 566         do {
 567                 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
 568         } while (!ret);
 569
 570         for (i = 0; i < nr_threads; i++) {
 571                 struct test_driver *t = &tdriver[i];
 572                 int j;
 573
 574                 if (!IS_ERR(t->task))
 575                         kthread_stop(t->task);
 576
 577                 for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
 578                         if (!((run_test_mask & (1 << j)) >> j))
 579                                 continue;
 580
 581                         pr_info(
 582                                 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
 583                                 test_case_array[j].test_name,
 584                                 t->data[j].test_passed,
 585                                 t->data[j].test_failed,
 586                                 test_repeat_count, test_loop_count,
 587                                 t->data[j].time);
 588                 }
 589
 590                 pr_info("All test took worker%d=%lu cycles\n",
 591                         i, t->stop - t->start);
 592         }
 593
 594         kvfree(tdriver);
 595 }
 596
 597 static int vmalloc_test_init(void)
 598 {
 599         do_concurrent_test();
 600         return -EAGAIN; /* Fail will directly unload the module */
 601 }
 602
 603 module_init(vmalloc_test_init)
 604
 605 MODULE_LICENSE("GPL");
 606 MODULE_AUTHOR("Uladzislau Rezki");
 607 MODULE_DESCRIPTION("vmalloc test module");