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");
608
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