xref: /openbmc/linux/lib/test_vmalloc.c (revision ecefa105) 
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(bool, use_huge, false,
42 	"Use vmalloc_huge in fix_size_alloc_test");
43 
44 __param(int, run_test_mask, INT_MAX,
45 	"Set tests specified in the mask.\n\n"
46 		"\t\tid: 1,    name: fix_size_alloc_test\n"
47 		"\t\tid: 2,    name: full_fit_alloc_test\n"
48 		"\t\tid: 4,    name: long_busy_list_alloc_test\n"
49 		"\t\tid: 8,    name: random_size_alloc_test\n"
50 		"\t\tid: 16,   name: fix_align_alloc_test\n"
51 		"\t\tid: 32,   name: random_size_align_alloc_test\n"
52 		"\t\tid: 64,   name: align_shift_alloc_test\n"
53 		"\t\tid: 128,  name: pcpu_alloc_test\n"
54 		"\t\tid: 256,  name: kvfree_rcu_1_arg_vmalloc_test\n"
55 		"\t\tid: 512,  name: kvfree_rcu_2_arg_vmalloc_test\n"
56 		/* Add a new test case description here. */
57 );
58 
59 /*
60  * Read write semaphore for synchronization of setup
61  * phase that is done in main thread and workers.
62  */
63 static DECLARE_RWSEM(prepare_for_test_rwsem);
64 
65 /*
66  * Completion tracking for worker threads.
67  */
68 static DECLARE_COMPLETION(test_all_done_comp);
69 static atomic_t test_n_undone = ATOMIC_INIT(0);
70 
71 static inline void
72 test_report_one_done(void)
73 {
74 	if (atomic_dec_and_test(&test_n_undone))
75 		complete(&test_all_done_comp);
76 }
77 
78 static int random_size_align_alloc_test(void)
79 {
80 	unsigned long size, align;
81 	unsigned int rnd;
82 	void *ptr;
83 	int i;
84 
85 	for (i = 0; i < test_loop_count; i++) {
86 		rnd = get_random_u8();
87 
88 		/*
89 		 * Maximum 1024 pages, if PAGE_SIZE is 4096.
90 		 */
91 		align = 1 << (rnd % 23);
92 
93 		/*
94 		 * Maximum 10 pages.
95 		 */
96 		size = ((rnd % 10) + 1) * PAGE_SIZE;
97 
98 		ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
99 				__builtin_return_address(0));
100 		if (!ptr)
101 			return -1;
102 
103 		vfree(ptr);
104 	}
105 
106 	return 0;
107 }
108 
109 /*
110  * This test case is supposed to be failed.
111  */
112 static int align_shift_alloc_test(void)
113 {
114 	unsigned long align;
115 	void *ptr;
116 	int i;
117 
118 	for (i = 0; i < BITS_PER_LONG; i++) {
119 		align = ((unsigned long) 1) << i;
120 
121 		ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
122 				__builtin_return_address(0));
123 		if (!ptr)
124 			return -1;
125 
126 		vfree(ptr);
127 	}
128 
129 	return 0;
130 }
131 
132 static int fix_align_alloc_test(void)
133 {
134 	void *ptr;
135 	int i;
136 
137 	for (i = 0; i < test_loop_count; i++) {
138 		ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
139 				GFP_KERNEL | __GFP_ZERO, 0,
140 				__builtin_return_address(0));
141 		if (!ptr)
142 			return -1;
143 
144 		vfree(ptr);
145 	}
146 
147 	return 0;
148 }
149 
150 static int random_size_alloc_test(void)
151 {
152 	unsigned int n;
153 	void *p;
154 	int i;
155 
156 	for (i = 0; i < test_loop_count; i++) {
157 		n = get_random_u32_inclusive(1, 100);
158 		p = vmalloc(n * PAGE_SIZE);
159 
160 		if (!p)
161 			return -1;
162 
163 		*((__u8 *)p) = 1;
164 		vfree(p);
165 	}
166 
167 	return 0;
168 }
169 
170 static int long_busy_list_alloc_test(void)
171 {
172 	void *ptr_1, *ptr_2;
173 	void **ptr;
174 	int rv = -1;
175 	int i;
176 
177 	ptr = vmalloc(sizeof(void *) * 15000);
178 	if (!ptr)
179 		return rv;
180 
181 	for (i = 0; i < 15000; i++)
182 		ptr[i] = vmalloc(1 * PAGE_SIZE);
183 
184 	for (i = 0; i < test_loop_count; i++) {
185 		ptr_1 = vmalloc(100 * PAGE_SIZE);
186 		if (!ptr_1)
187 			goto leave;
188 
189 		ptr_2 = vmalloc(1 * PAGE_SIZE);
190 		if (!ptr_2) {
191 			vfree(ptr_1);
192 			goto leave;
193 		}
194 
195 		*((__u8 *)ptr_1) = 0;
196 		*((__u8 *)ptr_2) = 1;
197 
198 		vfree(ptr_1);
199 		vfree(ptr_2);
200 	}
201 
202 	/*  Success */
203 	rv = 0;
204 
205 leave:
206 	for (i = 0; i < 15000; i++)
207 		vfree(ptr[i]);
208 
209 	vfree(ptr);
210 	return rv;
211 }
212 
213 static int full_fit_alloc_test(void)
214 {
215 	void **ptr, **junk_ptr, *tmp;
216 	int junk_length;
217 	int rv = -1;
218 	int i;
219 
220 	junk_length = fls(num_online_cpus());
221 	junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
222 
223 	ptr = vmalloc(sizeof(void *) * junk_length);
224 	if (!ptr)
225 		return rv;
226 
227 	junk_ptr = vmalloc(sizeof(void *) * junk_length);
228 	if (!junk_ptr) {
229 		vfree(ptr);
230 		return rv;
231 	}
232 
233 	for (i = 0; i < junk_length; i++) {
234 		ptr[i] = vmalloc(1 * PAGE_SIZE);
235 		junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
236 	}
237 
238 	for (i = 0; i < junk_length; i++)
239 		vfree(junk_ptr[i]);
240 
241 	for (i = 0; i < test_loop_count; i++) {
242 		tmp = vmalloc(1 * PAGE_SIZE);
243 
244 		if (!tmp)
245 			goto error;
246 
247 		*((__u8 *)tmp) = 1;
248 		vfree(tmp);
249 	}
250 
251 	/* Success */
252 	rv = 0;
253 
254 error:
255 	for (i = 0; i < junk_length; i++)
256 		vfree(ptr[i]);
257 
258 	vfree(ptr);
259 	vfree(junk_ptr);
260 
261 	return rv;
262 }
263 
264 static int fix_size_alloc_test(void)
265 {
266 	void *ptr;
267 	int i;
268 
269 	for (i = 0; i < test_loop_count; i++) {
270 		if (use_huge)
271 			ptr = vmalloc_huge((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE, GFP_KERNEL);
272 		else
273 			ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE);
274 
275 		if (!ptr)
276 			return -1;
277 
278 		*((__u8 *)ptr) = 0;
279 
280 		vfree(ptr);
281 	}
282 
283 	return 0;
284 }
285 
286 static int
287 pcpu_alloc_test(void)
288 {
289 	int rv = 0;
290 #ifndef CONFIG_NEED_PER_CPU_KM
291 	void __percpu **pcpu;
292 	size_t size, align;
293 	int i;
294 
295 	pcpu = vmalloc(sizeof(void __percpu *) * 35000);
296 	if (!pcpu)
297 		return -1;
298 
299 	for (i = 0; i < 35000; i++) {
300 		size = get_random_u32_inclusive(1, PAGE_SIZE / 4);
301 
302 		/*
303 		 * Maximum PAGE_SIZE
304 		 */
305 		align = 1 << get_random_u32_inclusive(1, 11);
306 
307 		pcpu[i] = __alloc_percpu(size, align);
308 		if (!pcpu[i])
309 			rv = -1;
310 	}
311 
312 	for (i = 0; i < 35000; i++)
313 		free_percpu(pcpu[i]);
314 
315 	vfree(pcpu);
316 #endif
317 	return rv;
318 }
319 
320 struct test_kvfree_rcu {
321 	struct rcu_head rcu;
322 	unsigned char array[20];
323 };
324 
325 static int
326 kvfree_rcu_1_arg_vmalloc_test(void)
327 {
328 	struct test_kvfree_rcu *p;
329 	int i;
330 
331 	for (i = 0; i < test_loop_count; i++) {
332 		p = vmalloc(1 * PAGE_SIZE);
333 		if (!p)
334 			return -1;
335 
336 		p->array[0] = 'a';
337 		kvfree_rcu(p);
338 	}
339 
340 	return 0;
341 }
342 
343 static int
344 kvfree_rcu_2_arg_vmalloc_test(void)
345 {
346 	struct test_kvfree_rcu *p;
347 	int i;
348 
349 	for (i = 0; i < test_loop_count; i++) {
350 		p = vmalloc(1 * PAGE_SIZE);
351 		if (!p)
352 			return -1;
353 
354 		p->array[0] = 'a';
355 		kvfree_rcu(p, rcu);
356 	}
357 
358 	return 0;
359 }
360 
361 struct test_case_desc {
362 	const char *test_name;
363 	int (*test_func)(void);
364 };
365 
366 static struct test_case_desc test_case_array[] = {
367 	{ "fix_size_alloc_test", fix_size_alloc_test },
368 	{ "full_fit_alloc_test", full_fit_alloc_test },
369 	{ "long_busy_list_alloc_test", long_busy_list_alloc_test },
370 	{ "random_size_alloc_test", random_size_alloc_test },
371 	{ "fix_align_alloc_test", fix_align_alloc_test },
372 	{ "random_size_align_alloc_test", random_size_align_alloc_test },
373 	{ "align_shift_alloc_test", align_shift_alloc_test },
374 	{ "pcpu_alloc_test", pcpu_alloc_test },
375 	{ "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
376 	{ "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
377 	/* Add a new test case here. */
378 };
379 
380 struct test_case_data {
381 	int test_failed;
382 	int test_passed;
383 	u64 time;
384 };
385 
386 static struct test_driver {
387 	struct task_struct *task;
388 	struct test_case_data data[ARRAY_SIZE(test_case_array)];
389 
390 	unsigned long start;
391 	unsigned long stop;
392 } *tdriver;
393 
394 static void shuffle_array(int *arr, int n)
395 {
396 	int i, j;
397 
398 	for (i = n - 1; i > 0; i--)  {
399 		/* Cut the range. */
400 		j = get_random_u32_below(i);
401 
402 		/* Swap indexes. */
403 		swap(arr[i], arr[j]);
404 	}
405 }
406 
407 static int test_func(void *private)
408 {
409 	struct test_driver *t = private;
410 	int random_array[ARRAY_SIZE(test_case_array)];
411 	int index, i, j;
412 	ktime_t kt;
413 	u64 delta;
414 
415 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
416 		random_array[i] = i;
417 
418 	if (!sequential_test_order)
419 		shuffle_array(random_array, ARRAY_SIZE(test_case_array));
420 
421 	/*
422 	 * Block until initialization is done.
423 	 */
424 	down_read(&prepare_for_test_rwsem);
425 
426 	t->start = get_cycles();
427 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
428 		index = random_array[i];
429 
430 		/*
431 		 * Skip tests if run_test_mask has been specified.
432 		 */
433 		if (!((run_test_mask & (1 << index)) >> index))
434 			continue;
435 
436 		kt = ktime_get();
437 		for (j = 0; j < test_repeat_count; j++) {
438 			if (!test_case_array[index].test_func())
439 				t->data[index].test_passed++;
440 			else
441 				t->data[index].test_failed++;
442 		}
443 
444 		/*
445 		 * Take an average time that test took.
446 		 */
447 		delta = (u64) ktime_us_delta(ktime_get(), kt);
448 		do_div(delta, (u32) test_repeat_count);
449 
450 		t->data[index].time = delta;
451 	}
452 	t->stop = get_cycles();
453 
454 	up_read(&prepare_for_test_rwsem);
455 	test_report_one_done();
456 
457 	/*
458 	 * Wait for the kthread_stop() call.
459 	 */
460 	while (!kthread_should_stop())
461 		msleep(10);
462 
463 	return 0;
464 }
465 
466 static int
467 init_test_configurtion(void)
468 {
469 	/*
470 	 * A maximum number of workers is defined as hard-coded
471 	 * value and set to USHRT_MAX. We add such gap just in
472 	 * case and for potential heavy stressing.
473 	 */
474 	nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
475 
476 	/* Allocate the space for test instances. */
477 	tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
478 	if (tdriver == NULL)
479 		return -1;
480 
481 	if (test_repeat_count <= 0)
482 		test_repeat_count = 1;
483 
484 	if (test_loop_count <= 0)
485 		test_loop_count = 1;
486 
487 	return 0;
488 }
489 
490 static void do_concurrent_test(void)
491 {
492 	int i, ret;
493 
494 	/*
495 	 * Set some basic configurations plus sanity check.
496 	 */
497 	ret = init_test_configurtion();
498 	if (ret < 0)
499 		return;
500 
501 	/*
502 	 * Put on hold all workers.
503 	 */
504 	down_write(&prepare_for_test_rwsem);
505 
506 	for (i = 0; i < nr_threads; i++) {
507 		struct test_driver *t = &tdriver[i];
508 
509 		t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
510 
511 		if (!IS_ERR(t->task))
512 			/* Success. */
513 			atomic_inc(&test_n_undone);
514 		else
515 			pr_err("Failed to start %d kthread\n", i);
516 	}
517 
518 	/*
519 	 * Now let the workers do their job.
520 	 */
521 	up_write(&prepare_for_test_rwsem);
522 
523 	/*
524 	 * Sleep quiet until all workers are done with 1 second
525 	 * interval. Since the test can take a lot of time we
526 	 * can run into a stack trace of the hung task. That is
527 	 * why we go with completion_timeout and HZ value.
528 	 */
529 	do {
530 		ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
531 	} while (!ret);
532 
533 	for (i = 0; i < nr_threads; i++) {
534 		struct test_driver *t = &tdriver[i];
535 		int j;
536 
537 		if (!IS_ERR(t->task))
538 			kthread_stop(t->task);
539 
540 		for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
541 			if (!((run_test_mask & (1 << j)) >> j))
542 				continue;
543 
544 			pr_info(
545 				"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
546 				test_case_array[j].test_name,
547 				t->data[j].test_passed,
548 				t->data[j].test_failed,
549 				test_repeat_count, test_loop_count,
550 				t->data[j].time);
551 		}
552 
553 		pr_info("All test took worker%d=%lu cycles\n",
554 			i, t->stop - t->start);
555 	}
556 
557 	kvfree(tdriver);
558 }
559 
560 static int vmalloc_test_init(void)
561 {
562 	do_concurrent_test();
563 	return -EAGAIN; /* Fail will directly unload the module */
564 }
565 
566 static void vmalloc_test_exit(void)
567 {
568 }
569 
570 module_init(vmalloc_test_init)
571 module_exit(vmalloc_test_exit)
572 
573 MODULE_LICENSE("GPL");
574 MODULE_AUTHOR("Uladzislau Rezki");
575 MODULE_DESCRIPTION("vmalloc test module");
576