xref: /openbmc/linux/lib/test_vmalloc.c (revision 249592bf) 
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, 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  */
57 static DECLARE_RWSEM(prepare_for_test_rwsem);
58 
59 /*
60  * Completion tracking for worker threads.
61  */
62 static DECLARE_COMPLETION(test_all_done_comp);
63 static atomic_t test_n_undone = ATOMIC_INIT(0);
64 
65 static inline void
66 test_report_one_done(void)
67 {
68 	if (atomic_dec_and_test(&test_n_undone))
69 		complete(&test_all_done_comp);
70 }
71 
72 static 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  */
105 static 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 
125 static 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 
143 static 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 
165 static 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 
200 leave:
201 	for (i = 0; i < 15000; i++)
202 		vfree(ptr[i]);
203 
204 	vfree(ptr);
205 	return rv;
206 }
207 
208 static 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 
249 error:
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 
259 static 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 
278 static int
279 pcpu_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 
316 struct test_kvfree_rcu {
317 	struct rcu_head rcu;
318 	unsigned char array[20];
319 };
320 
321 static int
322 kvfree_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 
339 static int
340 kvfree_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 
357 struct test_case_desc {
358 	const char *test_name;
359 	int (*test_func)(void);
360 };
361 
362 static 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 
376 struct test_case_data {
377 	int test_failed;
378 	int test_passed;
379 	u64 time;
380 };
381 
382 static 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 
390 static 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 
408 static 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 
467 static int
468 init_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 
491 static 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 
561 static int vmalloc_test_init(void)
562 {
563 	do_concurrent_test();
564 	return -EAGAIN; /* Fail will directly unload the module */
565 }
566 
567 static void vmalloc_test_exit(void)
568 {
569 }
570 
571 module_init(vmalloc_test_init)
572 module_exit(vmalloc_test_exit)
573 
574 MODULE_LICENSE("GPL");
575 MODULE_AUTHOR("Uladzislau Rezki");
576 MODULE_DESCRIPTION("vmalloc test module");
577