xref: /openbmc/linux/lib/test_vmalloc.c (revision d8adf5b9) 
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
69 test_report_one_done(void)
70 {
71 	if (atomic_dec_and_test(&test_n_undone))
72 		complete(&test_all_done_comp);
73 }
74 
75 static 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  */
108 static 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 
128 static 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 
146 static 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 
168 static 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 
203 leave:
204 	for (i = 0; i < 15000; i++)
205 		vfree(ptr[i]);
206 
207 	vfree(ptr);
208 	return rv;
209 }
210 
211 static 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 
252 error:
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 
262 static 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 
281 static int
282 pcpu_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 
319 struct test_kvfree_rcu {
320 	struct rcu_head rcu;
321 	unsigned char array[20];
322 };
323 
324 static int
325 kvfree_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 
342 static int
343 kvfree_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 
360 struct test_case_desc {
361 	const char *test_name;
362 	int (*test_func)(void);
363 };
364 
365 static 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 
379 struct test_case_data {
380 	int test_failed;
381 	int test_passed;
382 	u64 time;
383 };
384 
385 static 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 
393 static 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 
409 static 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 
468 static int
469 init_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 
492 static 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 
562 static int vmalloc_test_init(void)
563 {
564 	do_concurrent_test();
565 	return -EAGAIN; /* Fail will directly unload the module */
566 }
567 
568 static void vmalloc_test_exit(void)
569 {
570 }
571 
572 module_init(vmalloc_test_init)
573 module_exit(vmalloc_test_exit)
574 
575 MODULE_LICENSE("GPL");
576 MODULE_AUTHOR("Uladzislau Rezki");
577 MODULE_DESCRIPTION("vmalloc test module");
578