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(bool, single_cpu_test, false,
27 "Use single first online CPU to run tests");
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 "\t\tid: 1024, name: kvfree_rcu_1_arg_slab_test\n"
51 "\t\tid: 2048, name: kvfree_rcu_2_arg_slab_test\n"
52 /* Add a new test case description here. */
53 );
54
55 /*
56 * Depends on single_cpu_test parameter. If it is true, then
57 * use first online CPU to trigger a test on, otherwise go with
58 * all online CPUs.
59 */
60 static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
61
62 /*
63 * Read write semaphore for synchronization of setup
64 * phase that is done in main thread and workers.
65 */
66 static DECLARE_RWSEM(prepare_for_test_rwsem);
67
68 /*
69 * Completion tracking for worker threads.
70 */
71 static DECLARE_COMPLETION(test_all_done_comp);
72 static atomic_t test_n_undone = ATOMIC_INIT(0);
73
74 static inline void
test_report_one_done(void)75 test_report_one_done(void)
76 {
77 if (atomic_dec_and_test(&test_n_undone))
78 complete(&test_all_done_comp);
79 }
80
random_size_align_alloc_test(void)81 static int random_size_align_alloc_test(void)
82 {
83 unsigned long size, align, rnd;
84 void *ptr;
85 int i;
86
87 for (i = 0; i < test_loop_count; i++) {
88 get_random_bytes(&rnd, sizeof(rnd));
89
90 /*
91 * Maximum 1024 pages, if PAGE_SIZE is 4096.
92 */
93 align = 1 << (rnd % 23);
94
95 /*
96 * Maximum 10 pages.
97 */
98 size = ((rnd % 10) + 1) * PAGE_SIZE;
99
100 ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
101 __builtin_return_address(0));
102 if (!ptr)
103 return -1;
104
105 vfree(ptr);
106 }
107
108 return 0;
109 }
110
111 /*
112 * This test case is supposed to be failed.
113 */
align_shift_alloc_test(void)114 static int align_shift_alloc_test(void)
115 {
116 unsigned long align;
117 void *ptr;
118 int i;
119
120 for (i = 0; i < BITS_PER_LONG; i++) {
121 align = ((unsigned long) 1) << i;
122
123 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
124 __builtin_return_address(0));
125 if (!ptr)
126 return -1;
127
128 vfree(ptr);
129 }
130
131 return 0;
132 }
133
fix_align_alloc_test(void)134 static int fix_align_alloc_test(void)
135 {
136 void *ptr;
137 int i;
138
139 for (i = 0; i < test_loop_count; i++) {
140 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
141 GFP_KERNEL | __GFP_ZERO, 0,
142 __builtin_return_address(0));
143 if (!ptr)
144 return -1;
145
146 vfree(ptr);
147 }
148
149 return 0;
150 }
151
random_size_alloc_test(void)152 static int random_size_alloc_test(void)
153 {
154 unsigned int n;
155 void *p;
156 int i;
157
158 for (i = 0; i < test_loop_count; i++) {
159 get_random_bytes(&n, sizeof(i));
160 n = (n % 100) + 1;
161
162 p = vmalloc(n * PAGE_SIZE);
163
164 if (!p)
165 return -1;
166
167 *((__u8 *)p) = 1;
168 vfree(p);
169 }
170
171 return 0;
172 }
173
long_busy_list_alloc_test(void)174 static int long_busy_list_alloc_test(void)
175 {
176 void *ptr_1, *ptr_2;
177 void **ptr;
178 int rv = -1;
179 int i;
180
181 ptr = vmalloc(sizeof(void *) * 15000);
182 if (!ptr)
183 return rv;
184
185 for (i = 0; i < 15000; i++)
186 ptr[i] = vmalloc(1 * PAGE_SIZE);
187
188 for (i = 0; i < test_loop_count; i++) {
189 ptr_1 = vmalloc(100 * PAGE_SIZE);
190 if (!ptr_1)
191 goto leave;
192
193 ptr_2 = vmalloc(1 * PAGE_SIZE);
194 if (!ptr_2) {
195 vfree(ptr_1);
196 goto leave;
197 }
198
199 *((__u8 *)ptr_1) = 0;
200 *((__u8 *)ptr_2) = 1;
201
202 vfree(ptr_1);
203 vfree(ptr_2);
204 }
205
206 /* Success */
207 rv = 0;
208
209 leave:
210 for (i = 0; i < 15000; i++)
211 vfree(ptr[i]);
212
213 vfree(ptr);
214 return rv;
215 }
216
full_fit_alloc_test(void)217 static int full_fit_alloc_test(void)
218 {
219 void **ptr, **junk_ptr, *tmp;
220 int junk_length;
221 int rv = -1;
222 int i;
223
224 junk_length = fls(num_online_cpus());
225 junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
226
227 ptr = vmalloc(sizeof(void *) * junk_length);
228 if (!ptr)
229 return rv;
230
231 junk_ptr = vmalloc(sizeof(void *) * junk_length);
232 if (!junk_ptr) {
233 vfree(ptr);
234 return rv;
235 }
236
237 for (i = 0; i < junk_length; i++) {
238 ptr[i] = vmalloc(1 * PAGE_SIZE);
239 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
240 }
241
242 for (i = 0; i < junk_length; i++)
243 vfree(junk_ptr[i]);
244
245 for (i = 0; i < test_loop_count; i++) {
246 tmp = vmalloc(1 * PAGE_SIZE);
247
248 if (!tmp)
249 goto error;
250
251 *((__u8 *)tmp) = 1;
252 vfree(tmp);
253 }
254
255 /* Success */
256 rv = 0;
257
258 error:
259 for (i = 0; i < junk_length; i++)
260 vfree(ptr[i]);
261
262 vfree(ptr);
263 vfree(junk_ptr);
264
265 return rv;
266 }
267
fix_size_alloc_test(void)268 static int fix_size_alloc_test(void)
269 {
270 void *ptr;
271 int i;
272
273 for (i = 0; i < test_loop_count; i++) {
274 ptr = vmalloc(3 * 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
pcpu_alloc_test(void)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 unsigned int r;
302
303 get_random_bytes(&r, sizeof(i));
304 size = (r % (PAGE_SIZE / 4)) + 1;
305
306 /*
307 * Maximum PAGE_SIZE
308 */
309 get_random_bytes(&r, sizeof(i));
310 align = 1 << ((i % 11) + 1);
311
312 pcpu[i] = __alloc_percpu(size, align);
313 if (!pcpu[i])
314 rv = -1;
315 }
316
317 for (i = 0; i < 35000; i++)
318 free_percpu(pcpu[i]);
319
320 vfree(pcpu);
321 #endif
322 return rv;
323 }
324
325 struct test_kvfree_rcu {
326 struct rcu_head rcu;
327 unsigned char array[20];
328 };
329
330 static int
kvfree_rcu_1_arg_vmalloc_test(void)331 kvfree_rcu_1_arg_vmalloc_test(void)
332 {
333 struct test_kvfree_rcu *p;
334 int i;
335
336 for (i = 0; i < test_loop_count; i++) {
337 p = vmalloc(1 * PAGE_SIZE);
338 if (!p)
339 return -1;
340
341 p->array[0] = 'a';
342 kvfree_rcu(p);
343 }
344
345 return 0;
346 }
347
348 static int
kvfree_rcu_2_arg_vmalloc_test(void)349 kvfree_rcu_2_arg_vmalloc_test(void)
350 {
351 struct test_kvfree_rcu *p;
352 int i;
353
354 for (i = 0; i < test_loop_count; i++) {
355 p = vmalloc(1 * PAGE_SIZE);
356 if (!p)
357 return -1;
358
359 p->array[0] = 'a';
360 kvfree_rcu(p, rcu);
361 }
362
363 return 0;
364 }
365
366 static int
kvfree_rcu_1_arg_slab_test(void)367 kvfree_rcu_1_arg_slab_test(void)
368 {
369 struct test_kvfree_rcu *p;
370 int i;
371
372 for (i = 0; i < test_loop_count; i++) {
373 p = kmalloc(sizeof(*p), GFP_KERNEL);
374 if (!p)
375 return -1;
376
377 p->array[0] = 'a';
378 kvfree_rcu(p);
379 }
380
381 return 0;
382 }
383
384 static int
kvfree_rcu_2_arg_slab_test(void)385 kvfree_rcu_2_arg_slab_test(void)
386 {
387 struct test_kvfree_rcu *p;
388 int i;
389
390 for (i = 0; i < test_loop_count; i++) {
391 p = kmalloc(sizeof(*p), GFP_KERNEL);
392 if (!p)
393 return -1;
394
395 p->array[0] = 'a';
396 kvfree_rcu(p, rcu);
397 }
398
399 return 0;
400 }
401
402 struct test_case_desc {
403 const char *test_name;
404 int (*test_func)(void);
405 };
406
407 static struct test_case_desc test_case_array[] = {
408 { "fix_size_alloc_test", fix_size_alloc_test },
409 { "full_fit_alloc_test", full_fit_alloc_test },
410 { "long_busy_list_alloc_test", long_busy_list_alloc_test },
411 { "random_size_alloc_test", random_size_alloc_test },
412 { "fix_align_alloc_test", fix_align_alloc_test },
413 { "random_size_align_alloc_test", random_size_align_alloc_test },
414 { "align_shift_alloc_test", align_shift_alloc_test },
415 { "pcpu_alloc_test", pcpu_alloc_test },
416 { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
417 { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
418 { "kvfree_rcu_1_arg_slab_test", kvfree_rcu_1_arg_slab_test },
419 { "kvfree_rcu_2_arg_slab_test", kvfree_rcu_2_arg_slab_test },
420 /* Add a new test case here. */
421 };
422
423 struct test_case_data {
424 int test_failed;
425 int test_passed;
426 u64 time;
427 };
428
429 /* Split it to get rid of: WARNING: line over 80 characters */
430 static struct test_case_data
431 per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
432
433 static struct test_driver {
434 struct task_struct *task;
435 unsigned long start;
436 unsigned long stop;
437 int cpu;
438 } per_cpu_test_driver[NR_CPUS];
439
shuffle_array(int * arr,int n)440 static void shuffle_array(int *arr, int n)
441 {
442 unsigned int rnd;
443 int i, j, x;
444
445 for (i = n - 1; i > 0; i--) {
446 get_random_bytes(&rnd, sizeof(rnd));
447
448 /* Cut the range. */
449 j = rnd % i;
450
451 /* Swap indexes. */
452 x = arr[i];
453 arr[i] = arr[j];
454 arr[j] = x;
455 }
456 }
457
test_func(void * private)458 static int test_func(void *private)
459 {
460 struct test_driver *t = private;
461 int random_array[ARRAY_SIZE(test_case_array)];
462 int index, i, j;
463 ktime_t kt;
464 u64 delta;
465
466 if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
467 pr_err("Failed to set affinity to %d CPU\n", t->cpu);
468
469 for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
470 random_array[i] = i;
471
472 if (!sequential_test_order)
473 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
474
475 /*
476 * Block until initialization is done.
477 */
478 down_read(&prepare_for_test_rwsem);
479
480 t->start = get_cycles();
481 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
482 index = random_array[i];
483
484 /*
485 * Skip tests if run_test_mask has been specified.
486 */
487 if (!((run_test_mask & (1 << index)) >> index))
488 continue;
489
490 kt = ktime_get();
491 for (j = 0; j < test_repeat_count; j++) {
492 if (!test_case_array[index].test_func())
493 per_cpu_test_data[t->cpu][index].test_passed++;
494 else
495 per_cpu_test_data[t->cpu][index].test_failed++;
496 }
497
498 /*
499 * Take an average time that test took.
500 */
501 delta = (u64) ktime_us_delta(ktime_get(), kt);
502 do_div(delta, (u32) test_repeat_count);
503
504 per_cpu_test_data[t->cpu][index].time = delta;
505 }
506 t->stop = get_cycles();
507
508 up_read(&prepare_for_test_rwsem);
509 test_report_one_done();
510
511 /*
512 * Wait for the kthread_stop() call.
513 */
514 while (!kthread_should_stop())
515 msleep(10);
516
517 return 0;
518 }
519
520 static void
init_test_configurtion(void)521 init_test_configurtion(void)
522 {
523 /*
524 * Reset all data of all CPUs.
525 */
526 memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
527
528 if (single_cpu_test)
529 cpumask_set_cpu(cpumask_first(cpu_online_mask),
530 &cpus_run_test_mask);
531 else
532 cpumask_and(&cpus_run_test_mask, cpu_online_mask,
533 cpu_online_mask);
534
535 if (test_repeat_count <= 0)
536 test_repeat_count = 1;
537
538 if (test_loop_count <= 0)
539 test_loop_count = 1;
540 }
541
do_concurrent_test(void)542 static void do_concurrent_test(void)
543 {
544 int cpu, ret;
545
546 /*
547 * Set some basic configurations plus sanity check.
548 */
549 init_test_configurtion();
550
551 /*
552 * Put on hold all workers.
553 */
554 down_write(&prepare_for_test_rwsem);
555
556 for_each_cpu(cpu, &cpus_run_test_mask) {
557 struct test_driver *t = &per_cpu_test_driver[cpu];
558
559 t->cpu = cpu;
560 t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
561
562 if (!IS_ERR(t->task))
563 /* Success. */
564 atomic_inc(&test_n_undone);
565 else
566 pr_err("Failed to start kthread for %d CPU\n", cpu);
567 }
568
569 /*
570 * Now let the workers do their job.
571 */
572 up_write(&prepare_for_test_rwsem);
573
574 /*
575 * Sleep quiet until all workers are done with 1 second
576 * interval. Since the test can take a lot of time we
577 * can run into a stack trace of the hung task. That is
578 * why we go with completion_timeout and HZ value.
579 */
580 do {
581 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
582 } while (!ret);
583
584 for_each_cpu(cpu, &cpus_run_test_mask) {
585 struct test_driver *t = &per_cpu_test_driver[cpu];
586 int i;
587
588 if (!IS_ERR(t->task))
589 kthread_stop(t->task);
590
591 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
592 if (!((run_test_mask & (1 << i)) >> i))
593 continue;
594
595 pr_info(
596 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
597 test_case_array[i].test_name,
598 per_cpu_test_data[cpu][i].test_passed,
599 per_cpu_test_data[cpu][i].test_failed,
600 test_repeat_count, test_loop_count,
601 per_cpu_test_data[cpu][i].time);
602 }
603
604 pr_info("All test took CPU%d=%lu cycles\n",
605 cpu, t->stop - t->start);
606 }
607 }
608
vmalloc_test_init(void)609 static int vmalloc_test_init(void)
610 {
611 do_concurrent_test();
612 return -EAGAIN; /* Fail will directly unload the module */
613 }
614
vmalloc_test_exit(void)615 static void vmalloc_test_exit(void)
616 {
617 }
618
619 module_init(vmalloc_test_init)
620 module_exit(vmalloc_test_exit)
621
622 MODULE_LICENSE("GPL");
623 MODULE_AUTHOR("Uladzislau Rezki");
624 MODULE_DESCRIPTION("vmalloc test module");
625
