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(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 */
60 static DECLARE_RWSEM(prepare_for_test_rwsem);
61
62 /*
63 * Completion tracking for worker threads.
64 */
65 static DECLARE_COMPLETION(test_all_done_comp);
66 static atomic_t test_n_undone = ATOMIC_INIT(0);
67
68 static inline void
test_report_one_done(void)69 test_report_one_done(void)
70 {
71 if (atomic_dec_and_test(&test_n_undone))
72 complete(&test_all_done_comp);
73 }
74
random_size_align_alloc_test(void)75 static int random_size_align_alloc_test(void)
76 {
77 unsigned long size, align;
78 unsigned int rnd;
79 void *ptr;
80 int i;
81
82 for (i = 0; i < test_loop_count; i++) {
83 rnd = get_random_u8();
84
85 /*
86 * Maximum 1024 pages, if PAGE_SIZE is 4096.
87 */
88 align = 1 << (rnd % 23);
89
90 /*
91 * Maximum 10 pages.
92 */
93 size = ((rnd % 10) + 1) * PAGE_SIZE;
94
95 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
96 __builtin_return_address(0));
97 if (!ptr)
98 return -1;
99
100 vfree(ptr);
101 }
102
103 return 0;
104 }
105
106 /*
107 * This test case is supposed to be failed.
108 */
align_shift_alloc_test(void)109 static int align_shift_alloc_test(void)
110 {
111 unsigned long align;
112 void *ptr;
113 int i;
114
115 for (i = 0; i < BITS_PER_LONG; i++) {
116 align = ((unsigned long) 1) << i;
117
118 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
119 __builtin_return_address(0));
120 if (!ptr)
121 return -1;
122
123 vfree(ptr);
124 }
125
126 return 0;
127 }
128
fix_align_alloc_test(void)129 static int fix_align_alloc_test(void)
130 {
131 void *ptr;
132 int i;
133
134 for (i = 0; i < test_loop_count; i++) {
135 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
136 GFP_KERNEL | __GFP_ZERO, 0,
137 __builtin_return_address(0));
138 if (!ptr)
139 return -1;
140
141 vfree(ptr);
142 }
143
144 return 0;
145 }
146
random_size_alloc_test(void)147 static int random_size_alloc_test(void)
148 {
149 unsigned int n;
150 void *p;
151 int i;
152
153 for (i = 0; i < test_loop_count; i++) {
154 n = prandom_u32_max(100) + 1;
155 p = vmalloc(n * PAGE_SIZE);
156
157 if (!p)
158 return -1;
159
160 *((__u8 *)p) = 1;
161 vfree(p);
162 }
163
164 return 0;
165 }
166
long_busy_list_alloc_test(void)167 static int long_busy_list_alloc_test(void)
168 {
169 void *ptr_1, *ptr_2;
170 void **ptr;
171 int rv = -1;
172 int i;
173
174 ptr = vmalloc(sizeof(void *) * 15000);
175 if (!ptr)
176 return rv;
177
178 for (i = 0; i < 15000; i++)
179 ptr[i] = vmalloc(1 * PAGE_SIZE);
180
181 for (i = 0; i < test_loop_count; i++) {
182 ptr_1 = vmalloc(100 * PAGE_SIZE);
183 if (!ptr_1)
184 goto leave;
185
186 ptr_2 = vmalloc(1 * PAGE_SIZE);
187 if (!ptr_2) {
188 vfree(ptr_1);
189 goto leave;
190 }
191
192 *((__u8 *)ptr_1) = 0;
193 *((__u8 *)ptr_2) = 1;
194
195 vfree(ptr_1);
196 vfree(ptr_2);
197 }
198
199 /* Success */
200 rv = 0;
201
202 leave:
203 for (i = 0; i < 15000; i++)
204 vfree(ptr[i]);
205
206 vfree(ptr);
207 return rv;
208 }
209
full_fit_alloc_test(void)210 static int full_fit_alloc_test(void)
211 {
212 void **ptr, **junk_ptr, *tmp;
213 int junk_length;
214 int rv = -1;
215 int i;
216
217 junk_length = fls(num_online_cpus());
218 junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
219
220 ptr = vmalloc(sizeof(void *) * junk_length);
221 if (!ptr)
222 return rv;
223
224 junk_ptr = vmalloc(sizeof(void *) * junk_length);
225 if (!junk_ptr) {
226 vfree(ptr);
227 return rv;
228 }
229
230 for (i = 0; i < junk_length; i++) {
231 ptr[i] = vmalloc(1 * PAGE_SIZE);
232 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
233 }
234
235 for (i = 0; i < junk_length; i++)
236 vfree(junk_ptr[i]);
237
238 for (i = 0; i < test_loop_count; i++) {
239 tmp = vmalloc(1 * PAGE_SIZE);
240
241 if (!tmp)
242 goto error;
243
244 *((__u8 *)tmp) = 1;
245 vfree(tmp);
246 }
247
248 /* Success */
249 rv = 0;
250
251 error:
252 for (i = 0; i < junk_length; i++)
253 vfree(ptr[i]);
254
255 vfree(ptr);
256 vfree(junk_ptr);
257
258 return rv;
259 }
260
fix_size_alloc_test(void)261 static int fix_size_alloc_test(void)
262 {
263 void *ptr;
264 int i;
265
266 for (i = 0; i < test_loop_count; i++) {
267 ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
268
269 if (!ptr)
270 return -1;
271
272 *((__u8 *)ptr) = 0;
273
274 vfree(ptr);
275 }
276
277 return 0;
278 }
279
280 static int
pcpu_alloc_test(void)281 pcpu_alloc_test(void)
282 {
283 int rv = 0;
284 #ifndef CONFIG_NEED_PER_CPU_KM
285 void __percpu **pcpu;
286 size_t size, align;
287 int i;
288
289 pcpu = vmalloc(sizeof(void __percpu *) * 35000);
290 if (!pcpu)
291 return -1;
292
293 for (i = 0; i < 35000; i++) {
294 size = prandom_u32_max(PAGE_SIZE / 4) + 1;
295
296 /*
297 * Maximum PAGE_SIZE
298 */
299 align = 1 << (prandom_u32_max(11) + 1);
300
301 pcpu[i] = __alloc_percpu(size, align);
302 if (!pcpu[i])
303 rv = -1;
304 }
305
306 for (i = 0; i < 35000; i++)
307 free_percpu(pcpu[i]);
308
309 vfree(pcpu);
310 #endif
311 return rv;
312 }
313
314 struct test_kvfree_rcu {
315 struct rcu_head rcu;
316 unsigned char array[20];
317 };
318
319 static int
kvfree_rcu_1_arg_vmalloc_test(void)320 kvfree_rcu_1_arg_vmalloc_test(void)
321 {
322 struct test_kvfree_rcu *p;
323 int i;
324
325 for (i = 0; i < test_loop_count; i++) {
326 p = vmalloc(1 * PAGE_SIZE);
327 if (!p)
328 return -1;
329
330 p->array[0] = 'a';
331 kvfree_rcu(p);
332 }
333
334 return 0;
335 }
336
337 static int
kvfree_rcu_2_arg_vmalloc_test(void)338 kvfree_rcu_2_arg_vmalloc_test(void)
339 {
340 struct test_kvfree_rcu *p;
341 int i;
342
343 for (i = 0; i < test_loop_count; i++) {
344 p = vmalloc(1 * PAGE_SIZE);
345 if (!p)
346 return -1;
347
348 p->array[0] = 'a';
349 kvfree_rcu(p, rcu);
350 }
351
352 return 0;
353 }
354
355 struct test_case_desc {
356 const char *test_name;
357 int (*test_func)(void);
358 };
359
360 static struct test_case_desc test_case_array[] = {
361 { "fix_size_alloc_test", fix_size_alloc_test },
362 { "full_fit_alloc_test", full_fit_alloc_test },
363 { "long_busy_list_alloc_test", long_busy_list_alloc_test },
364 { "random_size_alloc_test", random_size_alloc_test },
365 { "fix_align_alloc_test", fix_align_alloc_test },
366 { "random_size_align_alloc_test", random_size_align_alloc_test },
367 { "align_shift_alloc_test", align_shift_alloc_test },
368 { "pcpu_alloc_test", pcpu_alloc_test },
369 { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
370 { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
371 /* Add a new test case here. */
372 };
373
374 struct test_case_data {
375 int test_failed;
376 int test_passed;
377 u64 time;
378 };
379
380 static struct test_driver {
381 struct task_struct *task;
382 struct test_case_data data[ARRAY_SIZE(test_case_array)];
383
384 unsigned long start;
385 unsigned long stop;
386 } *tdriver;
387
shuffle_array(int * arr,int n)388 static void shuffle_array(int *arr, int n)
389 {
390 int i, j;
391
392 for (i = n - 1; i > 0; i--) {
393 /* Cut the range. */
394 j = prandom_u32_max(i);
395
396 /* Swap indexes. */
397 swap(arr[i], arr[j]);
398 }
399 }
400
test_func(void * private)401 static int test_func(void *private)
402 {
403 struct test_driver *t = private;
404 int random_array[ARRAY_SIZE(test_case_array)];
405 int index, i, j;
406 ktime_t kt;
407 u64 delta;
408
409 for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
410 random_array[i] = i;
411
412 if (!sequential_test_order)
413 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
414
415 /*
416 * Block until initialization is done.
417 */
418 down_read(&prepare_for_test_rwsem);
419
420 t->start = get_cycles();
421 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
422 index = random_array[i];
423
424 /*
425 * Skip tests if run_test_mask has been specified.
426 */
427 if (!((run_test_mask & (1 << index)) >> index))
428 continue;
429
430 kt = ktime_get();
431 for (j = 0; j < test_repeat_count; j++) {
432 if (!test_case_array[index].test_func())
433 t->data[index].test_passed++;
434 else
435 t->data[index].test_failed++;
436 }
437
438 /*
439 * Take an average time that test took.
440 */
441 delta = (u64) ktime_us_delta(ktime_get(), kt);
442 do_div(delta, (u32) test_repeat_count);
443
444 t->data[index].time = delta;
445 }
446 t->stop = get_cycles();
447
448 up_read(&prepare_for_test_rwsem);
449 test_report_one_done();
450
451 /*
452 * Wait for the kthread_stop() call.
453 */
454 while (!kthread_should_stop())
455 msleep(10);
456
457 return 0;
458 }
459
460 static int
init_test_configurtion(void)461 init_test_configurtion(void)
462 {
463 /*
464 * A maximum number of workers is defined as hard-coded
465 * value and set to USHRT_MAX. We add such gap just in
466 * case and for potential heavy stressing.
467 */
468 nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
469
470 /* Allocate the space for test instances. */
471 tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
472 if (tdriver == NULL)
473 return -1;
474
475 if (test_repeat_count <= 0)
476 test_repeat_count = 1;
477
478 if (test_loop_count <= 0)
479 test_loop_count = 1;
480
481 return 0;
482 }
483
do_concurrent_test(void)484 static void do_concurrent_test(void)
485 {
486 int i, ret;
487
488 /*
489 * Set some basic configurations plus sanity check.
490 */
491 ret = init_test_configurtion();
492 if (ret < 0)
493 return;
494
495 /*
496 * Put on hold all workers.
497 */
498 down_write(&prepare_for_test_rwsem);
499
500 for (i = 0; i < nr_threads; i++) {
501 struct test_driver *t = &tdriver[i];
502
503 t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
504
505 if (!IS_ERR(t->task))
506 /* Success. */
507 atomic_inc(&test_n_undone);
508 else
509 pr_err("Failed to start %d kthread\n", i);
510 }
511
512 /*
513 * Now let the workers do their job.
514 */
515 up_write(&prepare_for_test_rwsem);
516
517 /*
518 * Sleep quiet until all workers are done with 1 second
519 * interval. Since the test can take a lot of time we
520 * can run into a stack trace of the hung task. That is
521 * why we go with completion_timeout and HZ value.
522 */
523 do {
524 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
525 } while (!ret);
526
527 for (i = 0; i < nr_threads; i++) {
528 struct test_driver *t = &tdriver[i];
529 int j;
530
531 if (!IS_ERR(t->task))
532 kthread_stop(t->task);
533
534 for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
535 if (!((run_test_mask & (1 << j)) >> j))
536 continue;
537
538 pr_info(
539 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
540 test_case_array[j].test_name,
541 t->data[j].test_passed,
542 t->data[j].test_failed,
543 test_repeat_count, test_loop_count,
544 t->data[j].time);
545 }
546
547 pr_info("All test took worker%d=%lu cycles\n",
548 i, t->stop - t->start);
549 }
550
551 kvfree(tdriver);
552 }
553
vmalloc_test_init(void)554 static int vmalloc_test_init(void)
555 {
556 do_concurrent_test();
557 return -EAGAIN; /* Fail will directly unload the module */
558 }
559
vmalloc_test_exit(void)560 static void vmalloc_test_exit(void)
561 {
562 }
563
564 module_init(vmalloc_test_init)
565 module_exit(vmalloc_test_exit)
566
567 MODULE_LICENSE("GPL");
568 MODULE_AUTHOR("Uladzislau Rezki");
569 MODULE_DESCRIPTION("vmalloc test module");
570
