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(bool, single_cpu_test, false,
  27         "Use single first online CPU to run tests");
  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, run_test_mask, INT_MAX,
  39         "Set tests specified in the mask.\n\n"
  40                 "\t\tid: 1,    name: fix_size_alloc_test\n"
  41                 "\t\tid: 2,    name: full_fit_alloc_test\n"
  42                 "\t\tid: 4,    name: long_busy_list_alloc_test\n"
  43                 "\t\tid: 8,    name: random_size_alloc_test\n"
  44                 "\t\tid: 16,   name: fix_align_alloc_test\n"
  45                 "\t\tid: 32,   name: random_size_align_alloc_test\n"
  46                 "\t\tid: 64,   name: align_shift_alloc_test\n"
  47                 "\t\tid: 128,  name: pcpu_alloc_test\n"
  48                 "\t\tid: 256,  name: kvfree_rcu_1_arg_vmalloc_test\n"
  49                 "\t\tid: 512,  name: kvfree_rcu_2_arg_vmalloc_test\n"
  50                 "\t\tid: 1024, name: kvfree_rcu_1_arg_slab_test\n"
  51                 "\t\tid: 2048, name: kvfree_rcu_2_arg_slab_test\n"
  52                 /* Add a new test case description here. */
  53 );
  54
  55 /*
  56  * Depends on single_cpu_test parameter. If it is true, then
  57  * use first online CPU to trigger a test on, otherwise go with
  58  * all online CPUs.
  59  */
  60 static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
  61
  62 /*
  63  * Read write semaphore for synchronization of setup
  64  * phase that is done in main thread and workers.
  65  */
  66 static DECLARE_RWSEM(prepare_for_test_rwsem);
  67
  68 /*
  69  * Completion tracking for worker threads.
  70  */
  71 static DECLARE_COMPLETION(test_all_done_comp);
  72 static atomic_t test_n_undone = ATOMIC_INIT(0);
  73
  74 static inline void
  75 test_report_one_done(void)
  76 {
  77         if (atomic_dec_and_test(&test_n_undone))
  78                 complete(&test_all_done_comp);
  79 }
  80
  81 static int random_size_align_alloc_test(void)
  82 {
  83         unsigned long size, align, rnd;
  84         void *ptr;
  85         int i;
  86
  87         for (i = 0; i < test_loop_count; i++) {
  88                 get_random_bytes(&rnd, sizeof(rnd));
  89
  90                 /*
  91                  * Maximum 1024 pages, if PAGE_SIZE is 4096.
  92                  */
  93                 align = 1 << (rnd % 23);
  94
  95                 /*
  96                  * Maximum 10 pages.
  97                  */
  98                 size = ((rnd % 10) + 1) * PAGE_SIZE;
  99
 100                 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
 101                                 __builtin_return_address(0));
 102                 if (!ptr)
 103                         return -1;
 104
 105                 vfree(ptr);
 106         }
 107
 108         return 0;
 109 }
 110
 111 /*
 112  * This test case is supposed to be failed.
 113  */
 114 static int align_shift_alloc_test(void)
 115 {
 116         unsigned long align;
 117         void *ptr;
 118         int i;
 119
 120         for (i = 0; i < BITS_PER_LONG; i++) {
 121                 align = ((unsigned long) 1) << i;
 122
 123                 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
 124                                 __builtin_return_address(0));
 125                 if (!ptr)
 126                         return -1;
 127
 128                 vfree(ptr);
 129         }
 130
 131         return 0;
 132 }
 133
 134 static int fix_align_alloc_test(void)
 135 {
 136         void *ptr;
 137         int i;
 138
 139         for (i = 0; i < test_loop_count; i++) {
 140                 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
 141                                 GFP_KERNEL | __GFP_ZERO, 0,
 142                                 __builtin_return_address(0));
 143                 if (!ptr)
 144                         return -1;
 145
 146                 vfree(ptr);
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int random_size_alloc_test(void)
 153 {
 154         unsigned int n;
 155         void *p;
 156         int i;
 157
 158         for (i = 0; i < test_loop_count; i++) {
 159                 get_random_bytes(&n, sizeof(i));
 160                 n = (n % 100) + 1;
 161
 162                 p = vmalloc(n * PAGE_SIZE);
 163
 164                 if (!p)
 165                         return -1;
 166
 167                 *((__u8 *)p) = 1;
 168                 vfree(p);
 169         }
 170
 171         return 0;
 172 }
 173
 174 static int long_busy_list_alloc_test(void)
 175 {
 176         void *ptr_1, *ptr_2;
 177         void **ptr;
 178         int rv = -1;
 179         int i;
 180
 181         ptr = vmalloc(sizeof(void *) * 15000);
 182         if (!ptr)
 183                 return rv;
 184
 185         for (i = 0; i < 15000; i++)
 186                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 187
 188         for (i = 0; i < test_loop_count; i++) {
 189                 ptr_1 = vmalloc(100 * PAGE_SIZE);
 190                 if (!ptr_1)
 191                         goto leave;
 192
 193                 ptr_2 = vmalloc(1 * PAGE_SIZE);
 194                 if (!ptr_2) {
 195                         vfree(ptr_1);
 196                         goto leave;
 197                 }
 198
 199                 *((__u8 *)ptr_1) = 0;
 200                 *((__u8 *)ptr_2) = 1;
 201
 202                 vfree(ptr_1);
 203                 vfree(ptr_2);
 204         }
 205
 206         /*  Success */
 207         rv = 0;
 208
 209 leave:
 210         for (i = 0; i < 15000; i++)
 211                 vfree(ptr[i]);
 212
 213         vfree(ptr);
 214         return rv;
 215 }
 216
 217 static int full_fit_alloc_test(void)
 218 {
 219         void **ptr, **junk_ptr, *tmp;
 220         int junk_length;
 221         int rv = -1;
 222         int i;
 223
 224         junk_length = fls(num_online_cpus());
 225         junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
 226
 227         ptr = vmalloc(sizeof(void *) * junk_length);
 228         if (!ptr)
 229                 return rv;
 230
 231         junk_ptr = vmalloc(sizeof(void *) * junk_length);
 232         if (!junk_ptr) {
 233                 vfree(ptr);
 234                 return rv;
 235         }
 236
 237         for (i = 0; i < junk_length; i++) {
 238                 ptr[i] = vmalloc(1 * PAGE_SIZE);
 239                 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
 240         }
 241
 242         for (i = 0; i < junk_length; i++)
 243                 vfree(junk_ptr[i]);
 244
 245         for (i = 0; i < test_loop_count; i++) {
 246                 tmp = vmalloc(1 * PAGE_SIZE);
 247
 248                 if (!tmp)
 249                         goto error;
 250
 251                 *((__u8 *)tmp) = 1;
 252                 vfree(tmp);
 253         }
 254
 255         /* Success */
 256         rv = 0;
 257
 258 error:
 259         for (i = 0; i < junk_length; i++)
 260                 vfree(ptr[i]);
 261
 262         vfree(ptr);
 263         vfree(junk_ptr);
 264
 265         return rv;
 266 }
 267
 268 static int fix_size_alloc_test(void)
 269 {
 270         void *ptr;
 271         int i;
 272
 273         for (i = 0; i < test_loop_count; i++) {
 274                 ptr = vmalloc(3 * 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                 unsigned int r;
 302
 303                 get_random_bytes(&r, sizeof(i));
 304                 size = (r % (PAGE_SIZE / 4)) + 1;
 305
 306                 /*
 307                  * Maximum PAGE_SIZE
 308                  */
 309                 get_random_bytes(&r, sizeof(i));
 310                 align = 1 << ((i % 11) + 1);
 311
 312                 pcpu[i] = __alloc_percpu(size, align);
 313                 if (!pcpu[i])
 314                         rv = -1;
 315         }
 316
 317         for (i = 0; i < 35000; i++)
 318                 free_percpu(pcpu[i]);
 319
 320         vfree(pcpu);
 321 #endif
 322         return rv;
 323 }
 324
 325 struct test_kvfree_rcu {
 326         struct rcu_head rcu;
 327         unsigned char array[20];
 328 };
 329
 330 static int
 331 kvfree_rcu_1_arg_vmalloc_test(void)
 332 {
 333         struct test_kvfree_rcu *p;
 334         int i;
 335
 336         for (i = 0; i < test_loop_count; i++) {
 337                 p = vmalloc(1 * PAGE_SIZE);
 338                 if (!p)
 339                         return -1;
 340
 341                 p->array[0] = 'a';
 342                 kvfree_rcu(p);
 343         }
 344
 345         return 0;
 346 }
 347
 348 static int
 349 kvfree_rcu_2_arg_vmalloc_test(void)
 350 {
 351         struct test_kvfree_rcu *p;
 352         int i;
 353
 354         for (i = 0; i < test_loop_count; i++) {
 355                 p = vmalloc(1 * PAGE_SIZE);
 356                 if (!p)
 357                         return -1;
 358
 359                 p->array[0] = 'a';
 360                 kvfree_rcu(p, rcu);
 361         }
 362
 363         return 0;
 364 }
 365
 366 static int
 367 kvfree_rcu_1_arg_slab_test(void)
 368 {
 369         struct test_kvfree_rcu *p;
 370         int i;
 371
 372         for (i = 0; i < test_loop_count; i++) {
 373                 p = kmalloc(sizeof(*p), GFP_KERNEL);
 374                 if (!p)
 375                         return -1;
 376
 377                 p->array[0] = 'a';
 378                 kvfree_rcu(p);
 379         }
 380
 381         return 0;
 382 }
 383
 384 static int
 385 kvfree_rcu_2_arg_slab_test(void)
 386 {
 387         struct test_kvfree_rcu *p;
 388         int i;
 389
 390         for (i = 0; i < test_loop_count; i++) {
 391                 p = kmalloc(sizeof(*p), GFP_KERNEL);
 392                 if (!p)
 393                         return -1;
 394
 395                 p->array[0] = 'a';
 396                 kvfree_rcu(p, rcu);
 397         }
 398
 399         return 0;
 400 }
 401
 402 struct test_case_desc {
 403         const char *test_name;
 404         int (*test_func)(void);
 405 };
 406
 407 static struct test_case_desc test_case_array[] = {
 408         { "fix_size_alloc_test", fix_size_alloc_test },
 409         { "full_fit_alloc_test", full_fit_alloc_test },
 410         { "long_busy_list_alloc_test", long_busy_list_alloc_test },
 411         { "random_size_alloc_test", random_size_alloc_test },
 412         { "fix_align_alloc_test", fix_align_alloc_test },
 413         { "random_size_align_alloc_test", random_size_align_alloc_test },
 414         { "align_shift_alloc_test", align_shift_alloc_test },
 415         { "pcpu_alloc_test", pcpu_alloc_test },
 416         { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
 417         { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
 418         { "kvfree_rcu_1_arg_slab_test", kvfree_rcu_1_arg_slab_test },
 419         { "kvfree_rcu_2_arg_slab_test", kvfree_rcu_2_arg_slab_test },
 420         /* Add a new test case here. */
 421 };
 422
 423 struct test_case_data {
 424         int test_failed;
 425         int test_passed;
 426         u64 time;
 427 };
 428
 429 /* Split it to get rid of: WARNING: line over 80 characters */
 430 static struct test_case_data
 431         per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
 432
 433 static struct test_driver {
 434         struct task_struct *task;
 435         unsigned long start;
 436         unsigned long stop;
 437         int cpu;
 438 } per_cpu_test_driver[NR_CPUS];
 439
 440 static void shuffle_array(int *arr, int n)
 441 {
 442         unsigned int rnd;
 443         int i, j, x;
 444
 445         for (i = n - 1; i > 0; i--)  {
 446                 get_random_bytes(&rnd, sizeof(rnd));
 447
 448                 /* Cut the range. */
 449                 j = rnd % i;
 450
 451                 /* Swap indexes. */
 452                 x = arr[i];
 453                 arr[i] = arr[j];
 454                 arr[j] = x;
 455         }
 456 }
 457
 458 static int test_func(void *private)
 459 {
 460         struct test_driver *t = private;
 461         int random_array[ARRAY_SIZE(test_case_array)];
 462         int index, i, j;
 463         ktime_t kt;
 464         u64 delta;
 465
 466         if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
 467                 pr_err("Failed to set affinity to %d CPU\n", t->cpu);
 468
 469         for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
 470                 random_array[i] = i;
 471
 472         if (!sequential_test_order)
 473                 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
 474
 475         /*
 476          * Block until initialization is done.
 477          */
 478         down_read(&prepare_for_test_rwsem);
 479
 480         t->start = get_cycles();
 481         for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 482                 index = random_array[i];
 483
 484                 /*
 485                  * Skip tests if run_test_mask has been specified.
 486                  */
 487                 if (!((run_test_mask & (1 << index)) >> index))
 488                         continue;
 489
 490                 kt = ktime_get();
 491                 for (j = 0; j < test_repeat_count; j++) {
 492                         if (!test_case_array[index].test_func())
 493                                 per_cpu_test_data[t->cpu][index].test_passed++;
 494                         else
 495                                 per_cpu_test_data[t->cpu][index].test_failed++;
 496                 }
 497
 498                 /*
 499                  * Take an average time that test took.
 500                  */
 501                 delta = (u64) ktime_us_delta(ktime_get(), kt);
 502                 do_div(delta, (u32) test_repeat_count);
 503
 504                 per_cpu_test_data[t->cpu][index].time = delta;
 505         }
 506         t->stop = get_cycles();
 507
 508         up_read(&prepare_for_test_rwsem);
 509         test_report_one_done();
 510
 511         /*
 512          * Wait for the kthread_stop() call.
 513          */
 514         while (!kthread_should_stop())
 515                 msleep(10);
 516
 517         return 0;
 518 }
 519
 520 static void
 521 init_test_configurtion(void)
 522 {
 523         /*
 524          * Reset all data of all CPUs.
 525          */
 526         memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
 527
 528         if (single_cpu_test)
 529                 cpumask_set_cpu(cpumask_first(cpu_online_mask),
 530                         &cpus_run_test_mask);
 531         else
 532                 cpumask_and(&cpus_run_test_mask, cpu_online_mask,
 533                         cpu_online_mask);
 534
 535         if (test_repeat_count <= 0)
 536                 test_repeat_count = 1;
 537
 538         if (test_loop_count <= 0)
 539                 test_loop_count = 1;
 540 }
 541
 542 static void do_concurrent_test(void)
 543 {
 544         int cpu, ret;
 545
 546         /*
 547          * Set some basic configurations plus sanity check.
 548          */
 549         init_test_configurtion();
 550
 551         /*
 552          * Put on hold all workers.
 553          */
 554         down_write(&prepare_for_test_rwsem);
 555
 556         for_each_cpu(cpu, &cpus_run_test_mask) {
 557                 struct test_driver *t = &per_cpu_test_driver[cpu];
 558
 559                 t->cpu = cpu;
 560                 t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
 561
 562                 if (!IS_ERR(t->task))
 563                         /* Success. */
 564                         atomic_inc(&test_n_undone);
 565                 else
 566                         pr_err("Failed to start kthread for %d CPU\n", cpu);
 567         }
 568
 569         /*
 570          * Now let the workers do their job.
 571          */
 572         up_write(&prepare_for_test_rwsem);
 573
 574         /*
 575          * Sleep quiet until all workers are done with 1 second
 576          * interval. Since the test can take a lot of time we
 577          * can run into a stack trace of the hung task. That is
 578          * why we go with completion_timeout and HZ value.
 579          */
 580         do {
 581                 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
 582         } while (!ret);
 583
 584         for_each_cpu(cpu, &cpus_run_test_mask) {
 585                 struct test_driver *t = &per_cpu_test_driver[cpu];
 586                 int i;
 587
 588                 if (!IS_ERR(t->task))
 589                         kthread_stop(t->task);
 590
 591                 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
 592                         if (!((run_test_mask & (1 << i)) >> i))
 593                                 continue;
 594
 595                         pr_info(
 596                                 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
 597                                 test_case_array[i].test_name,
 598                                 per_cpu_test_data[cpu][i].test_passed,
 599                                 per_cpu_test_data[cpu][i].test_failed,
 600                                 test_repeat_count, test_loop_count,
 601                                 per_cpu_test_data[cpu][i].time);
 602                 }
 603
 604                 pr_info("All test took CPU%d=%lu cycles\n",
 605                         cpu, t->stop - t->start);
 606         }
 607 }
 608
 609 static int vmalloc_test_init(void)
 610 {
 611         do_concurrent_test();
 612         return -EAGAIN; /* Fail will directly unload the module */
 613 }
 614
 615 static void vmalloc_test_exit(void)
 616 {
 617 }
 618
 619 module_init(vmalloc_test_init)
 620 module_exit(vmalloc_test_exit)
 621
 622 MODULE_LICENSE("GPL");
 623 MODULE_AUTHOR("Uladzislau Rezki");
 624 MODULE_DESCRIPTION("vmalloc test module");