projects/linux·blob v5.13-rc5 · 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, 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 /* Add a new test case description here. */
51);
52
53/*
54 * Read write semaphore for synchronization of setup
55 * phase that is done in main thread and workers.
56 */
57static DECLARE_RWSEM(prepare_for_test_rwsem);
58
59/*
60 * Completion tracking for worker threads.
61 */
62static DECLARE_COMPLETION(test_all_done_comp);
63static atomic_t test_n_undone = ATOMIC_INIT(0);
64
65static inline void
66test_report_one_done(void)
67{
68 if (atomic_dec_and_test(&test_n_undone))
69 complete(&test_all_done_comp);
70}
71
72static int random_size_align_alloc_test(void)
73{
74 unsigned long size, align, rnd;
75 void *ptr;
76 int i;
77
78 for (i = 0; i < test_loop_count; i++) {
79 get_random_bytes(&rnd, sizeof(rnd));
80
81 /*
82 * Maximum 1024 pages, if PAGE_SIZE is 4096.
83 */
84 align = 1 << (rnd % 23);
85
86 /*
87 * Maximum 10 pages.
88 */
89 size = ((rnd % 10) + 1) * PAGE_SIZE;
90
91 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
92 __builtin_return_address(0));
93 if (!ptr)
94 return -1;
95
96 vfree(ptr);
97 }
98
99 return 0;
100}
101
102/*
103 * This test case is supposed to be failed.
104 */
105static int align_shift_alloc_test(void)
106{
107 unsigned long align;
108 void *ptr;
109 int i;
110
111 for (i = 0; i < BITS_PER_LONG; i++) {
112 align = ((unsigned long) 1) << i;
113
114 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
115 __builtin_return_address(0));
116 if (!ptr)
117 return -1;
118
119 vfree(ptr);
120 }
121
122 return 0;
123}
124
125static int fix_align_alloc_test(void)
126{
127 void *ptr;
128 int i;
129
130 for (i = 0; i < test_loop_count; i++) {
131 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
132 GFP_KERNEL | __GFP_ZERO, 0,
133 __builtin_return_address(0));
134 if (!ptr)
135 return -1;
136
137 vfree(ptr);
138 }
139
140 return 0;
141}
142
143static int random_size_alloc_test(void)
144{
145 unsigned int n;
146 void *p;
147 int i;
148
149 for (i = 0; i < test_loop_count; i++) {
150 get_random_bytes(&n, sizeof(i));
151 n = (n % 100) + 1;
152
153 p = vmalloc(n * PAGE_SIZE);
154
155 if (!p)
156 return -1;
157
158 *((__u8 *)p) = 1;
159 vfree(p);
160 }
161
162 return 0;
163}
164
165static int long_busy_list_alloc_test(void)
166{
167 void *ptr_1, *ptr_2;
168 void **ptr;
169 int rv = -1;
170 int i;
171
172 ptr = vmalloc(sizeof(void *) * 15000);
173 if (!ptr)
174 return rv;
175
176 for (i = 0; i < 15000; i++)
177 ptr[i] = vmalloc(1 * PAGE_SIZE);
178
179 for (i = 0; i < test_loop_count; i++) {
180 ptr_1 = vmalloc(100 * PAGE_SIZE);
181 if (!ptr_1)
182 goto leave;
183
184 ptr_2 = vmalloc(1 * PAGE_SIZE);
185 if (!ptr_2) {
186 vfree(ptr_1);
187 goto leave;
188 }
189
190 *((__u8 *)ptr_1) = 0;
191 *((__u8 *)ptr_2) = 1;
192
193 vfree(ptr_1);
194 vfree(ptr_2);
195 }
196
197 /* Success */
198 rv = 0;
199
200leave:
201 for (i = 0; i < 15000; i++)
202 vfree(ptr[i]);
203
204 vfree(ptr);
205 return rv;
206}
207
208static int full_fit_alloc_test(void)
209{
210 void **ptr, **junk_ptr, *tmp;
211 int junk_length;
212 int rv = -1;
213 int i;
214
215 junk_length = fls(num_online_cpus());
216 junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
217
218 ptr = vmalloc(sizeof(void *) * junk_length);
219 if (!ptr)
220 return rv;
221
222 junk_ptr = vmalloc(sizeof(void *) * junk_length);
223 if (!junk_ptr) {
224 vfree(ptr);
225 return rv;
226 }
227
228 for (i = 0; i < junk_length; i++) {
229 ptr[i] = vmalloc(1 * PAGE_SIZE);
230 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
231 }
232
233 for (i = 0; i < junk_length; i++)
234 vfree(junk_ptr[i]);
235
236 for (i = 0; i < test_loop_count; i++) {
237 tmp = vmalloc(1 * PAGE_SIZE);
238
239 if (!tmp)
240 goto error;
241
242 *((__u8 *)tmp) = 1;
243 vfree(tmp);
244 }
245
246 /* Success */
247 rv = 0;
248
249error:
250 for (i = 0; i < junk_length; i++)
251 vfree(ptr[i]);
252
253 vfree(ptr);
254 vfree(junk_ptr);
255
256 return rv;
257}
258
259static int fix_size_alloc_test(void)
260{
261 void *ptr;
262 int i;
263
264 for (i = 0; i < test_loop_count; i++) {
265 ptr = vmalloc(3 * PAGE_SIZE);
266
267 if (!ptr)
268 return -1;
269
270 *((__u8 *)ptr) = 0;
271
272 vfree(ptr);
273 }
274
275 return 0;
276}
277
278static int
279pcpu_alloc_test(void)
280{
281 int rv = 0;
282#ifndef CONFIG_NEED_PER_CPU_KM
283 void __percpu **pcpu;
284 size_t size, align;
285 int i;
286
287 pcpu = vmalloc(sizeof(void __percpu *) * 35000);
288 if (!pcpu)
289 return -1;
290
291 for (i = 0; i < 35000; i++) {
292 unsigned int r;
293
294 get_random_bytes(&r, sizeof(i));
295 size = (r % (PAGE_SIZE / 4)) + 1;
296
297 /*
298 * Maximum PAGE_SIZE
299 */
300 get_random_bytes(&r, sizeof(i));
301 align = 1 << ((i % 11) + 1);
302
303 pcpu[i] = __alloc_percpu(size, align);
304 if (!pcpu[i])
305 rv = -1;
306 }
307
308 for (i = 0; i < 35000; i++)
309 free_percpu(pcpu[i]);
310
311 vfree(pcpu);
312#endif
313 return rv;
314}
315
316struct test_kvfree_rcu {
317 struct rcu_head rcu;
318 unsigned char array[20];
319};
320
321static int
322kvfree_rcu_1_arg_vmalloc_test(void)
323{
324 struct test_kvfree_rcu *p;
325 int i;
326
327 for (i = 0; i < test_loop_count; i++) {
328 p = vmalloc(1 * PAGE_SIZE);
329 if (!p)
330 return -1;
331
332 p->array[0] = 'a';
333 kvfree_rcu(p);
334 }
335
336 return 0;
337}
338
339static int
340kvfree_rcu_2_arg_vmalloc_test(void)
341{
342 struct test_kvfree_rcu *p;
343 int i;
344
345 for (i = 0; i < test_loop_count; i++) {
346 p = vmalloc(1 * PAGE_SIZE);
347 if (!p)
348 return -1;
349
350 p->array[0] = 'a';
351 kvfree_rcu(p, rcu);
352 }
353
354 return 0;
355}
356
357struct test_case_desc {
358 const char *test_name;
359 int (*test_func)(void);
360};
361
362static struct test_case_desc test_case_array[] = {
363 { "fix_size_alloc_test", fix_size_alloc_test },
364 { "full_fit_alloc_test", full_fit_alloc_test },
365 { "long_busy_list_alloc_test", long_busy_list_alloc_test },
366 { "random_size_alloc_test", random_size_alloc_test },
367 { "fix_align_alloc_test", fix_align_alloc_test },
368 { "random_size_align_alloc_test", random_size_align_alloc_test },
369 { "align_shift_alloc_test", align_shift_alloc_test },
370 { "pcpu_alloc_test", pcpu_alloc_test },
371 { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
372 { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
373 /* Add a new test case here. */
374};
375
376struct test_case_data {
377 int test_failed;
378 int test_passed;
379 u64 time;
380};
381
382static struct test_driver {
383 struct task_struct *task;
384 struct test_case_data data[ARRAY_SIZE(test_case_array)];
385
386 unsigned long start;
387 unsigned long stop;
388} *tdriver;
389
390static void shuffle_array(int *arr, int n)
391{
392 unsigned int rnd;
393 int i, j, x;
394
395 for (i = n - 1; i > 0; i--) {
396 get_random_bytes(&rnd, sizeof(rnd));
397
398 /* Cut the range. */
399 j = rnd % i;
400
401 /* Swap indexes. */
402 x = arr[i];
403 arr[i] = arr[j];
404 arr[j] = x;
405 }
406}
407
408static int test_func(void *private)
409{
410 struct test_driver *t = private;
411 int random_array[ARRAY_SIZE(test_case_array)];
412 int index, i, j;
413 ktime_t kt;
414 u64 delta;
415
416 for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
417 random_array[i] = i;
418
419 if (!sequential_test_order)
420 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
421
422 /*
423 * Block until initialization is done.
424 */
425 down_read(&prepare_for_test_rwsem);
426
427 t->start = get_cycles();
428 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
429 index = random_array[i];
430
431 /*
432 * Skip tests if run_test_mask has been specified.
433 */
434 if (!((run_test_mask & (1 << index)) >> index))
435 continue;
436
437 kt = ktime_get();
438 for (j = 0; j < test_repeat_count; j++) {
439 if (!test_case_array[index].test_func())
440 t->data[index].test_passed++;
441 else
442 t->data[index].test_failed++;
443 }
444
445 /*
446 * Take an average time that test took.
447 */
448 delta = (u64) ktime_us_delta(ktime_get(), kt);
449 do_div(delta, (u32) test_repeat_count);
450
451 t->data[index].time = delta;
452 }
453 t->stop = get_cycles();
454
455 up_read(&prepare_for_test_rwsem);
456 test_report_one_done();
457
458 /*
459 * Wait for the kthread_stop() call.
460 */
461 while (!kthread_should_stop())
462 msleep(10);
463
464 return 0;
465}
466
467static int
468init_test_configurtion(void)
469{
470 /*
471 * A maximum number of workers is defined as hard-coded
472 * value and set to USHRT_MAX. We add such gap just in
473 * case and for potential heavy stressing.
474 */
475 nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
476
477 /* Allocate the space for test instances. */
478 tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
479 if (tdriver == NULL)
480 return -1;
481
482 if (test_repeat_count <= 0)
483 test_repeat_count = 1;
484
485 if (test_loop_count <= 0)
486 test_loop_count = 1;
487
488 return 0;
489}
490
491static void do_concurrent_test(void)
492{
493 int i, ret;
494
495 /*
496 * Set some basic configurations plus sanity check.
497 */
498 ret = init_test_configurtion();
499 if (ret < 0)
500 return;
501
502 /*
503 * Put on hold all workers.
504 */
505 down_write(&prepare_for_test_rwsem);
506
507 for (i = 0; i < nr_threads; i++) {
508 struct test_driver *t = &tdriver[i];
509
510 t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
511
512 if (!IS_ERR(t->task))
513 /* Success. */
514 atomic_inc(&test_n_undone);
515 else
516 pr_err("Failed to start %d kthread\n", i);
517 }
518
519 /*
520 * Now let the workers do their job.
521 */
522 up_write(&prepare_for_test_rwsem);
523
524 /*
525 * Sleep quiet until all workers are done with 1 second
526 * interval. Since the test can take a lot of time we
527 * can run into a stack trace of the hung task. That is
528 * why we go with completion_timeout and HZ value.
529 */
530 do {
531 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
532 } while (!ret);
533
534 for (i = 0; i < nr_threads; i++) {
535 struct test_driver *t = &tdriver[i];
536 int j;
537
538 if (!IS_ERR(t->task))
539 kthread_stop(t->task);
540
541 for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
542 if (!((run_test_mask & (1 << j)) >> j))
543 continue;
544
545 pr_info(
546 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
547 test_case_array[j].test_name,
548 t->data[j].test_passed,
549 t->data[j].test_failed,
550 test_repeat_count, test_loop_count,
551 t->data[j].time);
552 }
553
554 pr_info("All test took worker%d=%lu cycles\n",
555 i, t->stop - t->start);
556 }
557
558 kvfree(tdriver);
559}
560
561static int vmalloc_test_init(void)
562{
563 do_concurrent_test();
564 return -EAGAIN; /* Fail will directly unload the module */
565}
566
567static void vmalloc_test_exit(void)
568{
569}
570
571module_init(vmalloc_test_init)
572module_exit(vmalloc_test_exit)
573
574MODULE_LICENSE("GPL");
575MODULE_AUTHOR("Uladzislau Rezki");
576MODULE_DESCRIPTION("vmalloc test module");