xref: /openbmc/linux/lib/test_vmalloc.c (revision 2a12187d) 
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;
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  */
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 
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 
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 = get_random_u32_inclusive(1, 100);
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 
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 
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 
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
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 = get_random_u32_inclusive(1, PAGE_SIZE / 4);
295 
296 		/*
297 		 * Maximum PAGE_SIZE
298 		 */
299 		align = 1 << get_random_u32_inclusive(1, 11);
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
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
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 
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 = get_random_u32_below(i);
395 
396 		/* Swap indexes. */
397 		swap(arr[i], arr[j]);
398 	}
399 }
400 
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
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 
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 
554 static int vmalloc_test_init(void)
555 {
556 	do_concurrent_test();
557 	return -EAGAIN; /* Fail will directly unload the module */
558 }
559 
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