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