projects/linux·blob v5.16-rc8 · refs

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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) <[email protected]>
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(int, run_test_mask, INT_MAX,
42 "Set tests specified in the mask.\n\n"
43 "\t\tid: 1, name: fix_size_alloc_test\n"
44 "\t\tid: 2, name: full_fit_alloc_test\n"
45 "\t\tid: 4, name: long_busy_list_alloc_test\n"
46 "\t\tid: 8, name: random_size_alloc_test\n"
47 "\t\tid: 16, name: fix_align_alloc_test\n"
48 "\t\tid: 32, name: random_size_align_alloc_test\n"
49 "\t\tid: 64, name: align_shift_alloc_test\n"
50 "\t\tid: 128, name: pcpu_alloc_test\n"
51 "\t\tid: 256, name: kvfree_rcu_1_arg_vmalloc_test\n"
52 "\t\tid: 512, name: kvfree_rcu_2_arg_vmalloc_test\n"
53 /* Add a new test case description here. */
54);
55
56/*
57 * Read write semaphore for synchronization of setup
58 * phase that is done in main thread and workers.
59 */
60static DECLARE_RWSEM(prepare_for_test_rwsem);
61
62/*
63 * Completion tracking for worker threads.
64 */
65static DECLARE_COMPLETION(test_all_done_comp);
66static atomic_t test_n_undone = ATOMIC_INIT(0);
67
68static inline void
69test_report_one_done(void)
70{
71 if (atomic_dec_and_test(&test_n_undone))
72 complete(&test_all_done_comp);
73}
74
75static 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 */
108static 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
128static 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
146static 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
168static 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
203leave:
204 for (i = 0; i < 15000; i++)
205 vfree(ptr[i]);
206
207 vfree(ptr);
208 return rv;
209}
210
211static 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
252error:
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
262static 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((nr_pages > 0 ? nr_pages:1) * 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
281static int
282pcpu_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
319struct test_kvfree_rcu {
320 struct rcu_head rcu;
321 unsigned char array[20];
322};
323
324static int
325kvfree_rcu_1_arg_vmalloc_test(void)
326{
327 struct test_kvfree_rcu *p;
328 int i;
329
330 for (i = 0; i < test_loop_count; i++) {
331 p = vmalloc(1 * PAGE_SIZE);
332 if (!p)
333 return -1;
334
335 p->array[0] = 'a';
336 kvfree_rcu(p);
337 }
338
339 return 0;
340}
341
342static int
343kvfree_rcu_2_arg_vmalloc_test(void)
344{
345 struct test_kvfree_rcu *p;
346 int i;
347
348 for (i = 0; i < test_loop_count; i++) {
349 p = vmalloc(1 * PAGE_SIZE);
350 if (!p)
351 return -1;
352
353 p->array[0] = 'a';
354 kvfree_rcu(p, rcu);
355 }
356
357 return 0;
358}
359
360struct test_case_desc {
361 const char *test_name;
362 int (*test_func)(void);
363};
364
365static struct test_case_desc test_case_array[] = {
366 { "fix_size_alloc_test", fix_size_alloc_test },
367 { "full_fit_alloc_test", full_fit_alloc_test },
368 { "long_busy_list_alloc_test", long_busy_list_alloc_test },
369 { "random_size_alloc_test", random_size_alloc_test },
370 { "fix_align_alloc_test", fix_align_alloc_test },
371 { "random_size_align_alloc_test", random_size_align_alloc_test },
372 { "align_shift_alloc_test", align_shift_alloc_test },
373 { "pcpu_alloc_test", pcpu_alloc_test },
374 { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
375 { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
376 /* Add a new test case here. */
377};
378
379struct test_case_data {
380 int test_failed;
381 int test_passed;
382 u64 time;
383};
384
385static struct test_driver {
386 struct task_struct *task;
387 struct test_case_data data[ARRAY_SIZE(test_case_array)];
388
389 unsigned long start;
390 unsigned long stop;
391} *tdriver;
392
393static void shuffle_array(int *arr, int n)
394{
395 unsigned int rnd;
396 int i, j;
397
398 for (i = n - 1; i > 0; i--) {
399 get_random_bytes(&rnd, sizeof(rnd));
400
401 /* Cut the range. */
402 j = rnd % i;
403
404 /* Swap indexes. */
405 swap(arr[i], arr[j]);
406 }
407}
408
409static int test_func(void *private)
410{
411 struct test_driver *t = private;
412 int random_array[ARRAY_SIZE(test_case_array)];
413 int index, i, j;
414 ktime_t kt;
415 u64 delta;
416
417 for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
418 random_array[i] = i;
419
420 if (!sequential_test_order)
421 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
422
423 /*
424 * Block until initialization is done.
425 */
426 down_read(&prepare_for_test_rwsem);
427
428 t->start = get_cycles();
429 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
430 index = random_array[i];
431
432 /*
433 * Skip tests if run_test_mask has been specified.
434 */
435 if (!((run_test_mask & (1 << index)) >> index))
436 continue;
437
438 kt = ktime_get();
439 for (j = 0; j < test_repeat_count; j++) {
440 if (!test_case_array[index].test_func())
441 t->data[index].test_passed++;
442 else
443 t->data[index].test_failed++;
444 }
445
446 /*
447 * Take an average time that test took.
448 */
449 delta = (u64) ktime_us_delta(ktime_get(), kt);
450 do_div(delta, (u32) test_repeat_count);
451
452 t->data[index].time = delta;
453 }
454 t->stop = get_cycles();
455
456 up_read(&prepare_for_test_rwsem);
457 test_report_one_done();
458
459 /*
460 * Wait for the kthread_stop() call.
461 */
462 while (!kthread_should_stop())
463 msleep(10);
464
465 return 0;
466}
467
468static int
469init_test_configurtion(void)
470{
471 /*
472 * A maximum number of workers is defined as hard-coded
473 * value and set to USHRT_MAX. We add such gap just in
474 * case and for potential heavy stressing.
475 */
476 nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
477
478 /* Allocate the space for test instances. */
479 tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
480 if (tdriver == NULL)
481 return -1;
482
483 if (test_repeat_count <= 0)
484 test_repeat_count = 1;
485
486 if (test_loop_count <= 0)
487 test_loop_count = 1;
488
489 return 0;
490}
491
492static void do_concurrent_test(void)
493{
494 int i, ret;
495
496 /*
497 * Set some basic configurations plus sanity check.
498 */
499 ret = init_test_configurtion();
500 if (ret < 0)
501 return;
502
503 /*
504 * Put on hold all workers.
505 */
506 down_write(&prepare_for_test_rwsem);
507
508 for (i = 0; i < nr_threads; i++) {
509 struct test_driver *t = &tdriver[i];
510
511 t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
512
513 if (!IS_ERR(t->task))
514 /* Success. */
515 atomic_inc(&test_n_undone);
516 else
517 pr_err("Failed to start %d kthread\n", i);
518 }
519
520 /*
521 * Now let the workers do their job.
522 */
523 up_write(&prepare_for_test_rwsem);
524
525 /*
526 * Sleep quiet until all workers are done with 1 second
527 * interval. Since the test can take a lot of time we
528 * can run into a stack trace of the hung task. That is
529 * why we go with completion_timeout and HZ value.
530 */
531 do {
532 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
533 } while (!ret);
534
535 for (i = 0; i < nr_threads; i++) {
536 struct test_driver *t = &tdriver[i];
537 int j;
538
539 if (!IS_ERR(t->task))
540 kthread_stop(t->task);
541
542 for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
543 if (!((run_test_mask & (1 << j)) >> j))
544 continue;
545
546 pr_info(
547 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
548 test_case_array[j].test_name,
549 t->data[j].test_passed,
550 t->data[j].test_failed,
551 test_repeat_count, test_loop_count,
552 t->data[j].time);
553 }
554
555 pr_info("All test took worker%d=%lu cycles\n",
556 i, t->stop - t->start);
557 }
558
559 kvfree(tdriver);
560}
561
562static int vmalloc_test_init(void)
563{
564 do_concurrent_test();
565 return -EAGAIN; /* Fail will directly unload the module */
566}
567
568static void vmalloc_test_exit(void)
569{
570}
571
572module_init(vmalloc_test_init)
573module_exit(vmalloc_test_exit)
574
575MODULE_LICENSE("GPL");
576MODULE_AUTHOR("Uladzislau Rezki");
577MODULE_DESCRIPTION("vmalloc test module");