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 		"\t\tid: 1024, name: vm_map_ram_test\n"
57 		/* Add a new test case description here. */
58 );
59 
60 /*
61  * Read write semaphore for synchronization of setup
62  * phase that is done in main thread and workers.
63  */
64 static DECLARE_RWSEM(prepare_for_test_rwsem);
65 
66 /*
67  * Completion tracking for worker threads.
68  */
69 static DECLARE_COMPLETION(test_all_done_comp);
70 static atomic_t test_n_undone = ATOMIC_INIT(0);
71 
72 static inline void
test_report_one_done(void)73 test_report_one_done(void)
74 {
75 	if (atomic_dec_and_test(&test_n_undone))
76 		complete(&test_all_done_comp);
77 }
78 
random_size_align_alloc_test(void)79 static int random_size_align_alloc_test(void)
80 {
81 	unsigned long size, align;
82 	unsigned int rnd;
83 	void *ptr;
84 	int i;
85 
86 	for (i = 0; i < test_loop_count; i++) {
87 		rnd = get_random_u8();
88 
89 		/*
90 		 * Maximum 1024 pages, if PAGE_SIZE is 4096.
91 		 */
92 		align = 1 << (rnd % 23);
93 
94 		/*
95 		 * Maximum 10 pages.
96 		 */
97 		size = ((rnd % 10) + 1) * PAGE_SIZE;
98 
99 		ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0,
100 				__builtin_return_address(0));
101 		if (!ptr)
102 			return -1;
103 
104 		vfree(ptr);
105 	}
106 
107 	return 0;
108 }
109 
110 /*
111  * This test case is supposed to be failed.
112  */
align_shift_alloc_test(void)113 static int align_shift_alloc_test(void)
114 {
115 	unsigned long align;
116 	void *ptr;
117 	int i;
118 
119 	for (i = 0; i < BITS_PER_LONG; i++) {
120 		align = 1UL << i;
121 
122 		ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
123 				__builtin_return_address(0));
124 		if (!ptr)
125 			return -1;
126 
127 		vfree(ptr);
128 	}
129 
130 	return 0;
131 }
132 
fix_align_alloc_test(void)133 static int fix_align_alloc_test(void)
134 {
135 	void *ptr;
136 	int i;
137 
138 	for (i = 0; i < test_loop_count; i++) {
139 		ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
140 				GFP_KERNEL | __GFP_ZERO, 0,
141 				__builtin_return_address(0));
142 		if (!ptr)
143 			return -1;
144 
145 		vfree(ptr);
146 	}
147 
148 	return 0;
149 }
150 
random_size_alloc_test(void)151 static int random_size_alloc_test(void)
152 {
153 	unsigned int n;
154 	void *p;
155 	int i;
156 
157 	for (i = 0; i < test_loop_count; i++) {
158 		n = get_random_u32_inclusive(1, 100);
159 		p = vmalloc(n * PAGE_SIZE);
160 
161 		if (!p)
162 			return -1;
163 
164 		*((__u8 *)p) = 1;
165 		vfree(p);
166 	}
167 
168 	return 0;
169 }
170 
long_busy_list_alloc_test(void)171 static int long_busy_list_alloc_test(void)
172 {
173 	void *ptr_1, *ptr_2;
174 	void **ptr;
175 	int rv = -1;
176 	int i;
177 
178 	ptr = vmalloc(sizeof(void *) * 15000);
179 	if (!ptr)
180 		return rv;
181 
182 	for (i = 0; i < 15000; i++)
183 		ptr[i] = vmalloc(1 * PAGE_SIZE);
184 
185 	for (i = 0; i < test_loop_count; i++) {
186 		ptr_1 = vmalloc(100 * PAGE_SIZE);
187 		if (!ptr_1)
188 			goto leave;
189 
190 		ptr_2 = vmalloc(1 * PAGE_SIZE);
191 		if (!ptr_2) {
192 			vfree(ptr_1);
193 			goto leave;
194 		}
195 
196 		*((__u8 *)ptr_1) = 0;
197 		*((__u8 *)ptr_2) = 1;
198 
199 		vfree(ptr_1);
200 		vfree(ptr_2);
201 	}
202 
203 	/*  Success */
204 	rv = 0;
205 
206 leave:
207 	for (i = 0; i < 15000; i++)
208 		vfree(ptr[i]);
209 
210 	vfree(ptr);
211 	return rv;
212 }
213 
full_fit_alloc_test(void)214 static int full_fit_alloc_test(void)
215 {
216 	void **ptr, **junk_ptr, *tmp;
217 	int junk_length;
218 	int rv = -1;
219 	int i;
220 
221 	junk_length = fls(num_online_cpus());
222 	junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
223 
224 	ptr = vmalloc(sizeof(void *) * junk_length);
225 	if (!ptr)
226 		return rv;
227 
228 	junk_ptr = vmalloc(sizeof(void *) * junk_length);
229 	if (!junk_ptr) {
230 		vfree(ptr);
231 		return rv;
232 	}
233 
234 	for (i = 0; i < junk_length; i++) {
235 		ptr[i] = vmalloc(1 * PAGE_SIZE);
236 		junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
237 	}
238 
239 	for (i = 0; i < junk_length; i++)
240 		vfree(junk_ptr[i]);
241 
242 	for (i = 0; i < test_loop_count; i++) {
243 		tmp = vmalloc(1 * PAGE_SIZE);
244 
245 		if (!tmp)
246 			goto error;
247 
248 		*((__u8 *)tmp) = 1;
249 		vfree(tmp);
250 	}
251 
252 	/* Success */
253 	rv = 0;
254 
255 error:
256 	for (i = 0; i < junk_length; i++)
257 		vfree(ptr[i]);
258 
259 	vfree(ptr);
260 	vfree(junk_ptr);
261 
262 	return rv;
263 }
264 
fix_size_alloc_test(void)265 static int fix_size_alloc_test(void)
266 {
267 	void *ptr;
268 	int i;
269 
270 	for (i = 0; i < test_loop_count; i++) {
271 		if (use_huge)
272 			ptr = vmalloc_huge((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE, GFP_KERNEL);
273 		else
274 			ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * 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 		size = get_random_u32_inclusive(1, PAGE_SIZE / 4);
302 
303 		/*
304 		 * Maximum PAGE_SIZE
305 		 */
306 		align = 1 << get_random_u32_inclusive(1, 11);
307 
308 		pcpu[i] = __alloc_percpu(size, align);
309 		if (!pcpu[i])
310 			rv = -1;
311 	}
312 
313 	for (i = 0; i < 35000; i++)
314 		free_percpu(pcpu[i]);
315 
316 	vfree(pcpu);
317 #endif
318 	return rv;
319 }
320 
321 struct test_kvfree_rcu {
322 	struct rcu_head rcu;
323 	unsigned char array[20];
324 };
325 
326 static int
kvfree_rcu_1_arg_vmalloc_test(void)327 kvfree_rcu_1_arg_vmalloc_test(void)
328 {
329 	struct test_kvfree_rcu *p;
330 	int i;
331 
332 	for (i = 0; i < test_loop_count; i++) {
333 		p = vmalloc(1 * PAGE_SIZE);
334 		if (!p)
335 			return -1;
336 
337 		p->array[0] = 'a';
338 		kvfree_rcu_mightsleep(p);
339 	}
340 
341 	return 0;
342 }
343 
344 static int
kvfree_rcu_2_arg_vmalloc_test(void)345 kvfree_rcu_2_arg_vmalloc_test(void)
346 {
347 	struct test_kvfree_rcu *p;
348 	int i;
349 
350 	for (i = 0; i < test_loop_count; i++) {
351 		p = vmalloc(1 * PAGE_SIZE);
352 		if (!p)
353 			return -1;
354 
355 		p->array[0] = 'a';
356 		kvfree_rcu(p, rcu);
357 	}
358 
359 	return 0;
360 }
361 
362 static int
vm_map_ram_test(void)363 vm_map_ram_test(void)
364 {
365 	unsigned long nr_allocated;
366 	unsigned int map_nr_pages;
367 	unsigned char *v_ptr;
368 	struct page **pages;
369 	int i;
370 
371 	map_nr_pages = nr_pages > 0 ? nr_pages:1;
372 	pages = kcalloc(map_nr_pages, sizeof(struct page *), GFP_KERNEL);
373 	if (!pages)
374 		return -1;
375 
376 	nr_allocated = alloc_pages_bulk_array(GFP_KERNEL, map_nr_pages, pages);
377 	if (nr_allocated != map_nr_pages)
378 		goto cleanup;
379 
380 	/* Run the test loop. */
381 	for (i = 0; i < test_loop_count; i++) {
382 		v_ptr = vm_map_ram(pages, map_nr_pages, NUMA_NO_NODE);
383 		*v_ptr = 'a';
384 		vm_unmap_ram(v_ptr, map_nr_pages);
385 	}
386 
387 cleanup:
388 	for (i = 0; i < nr_allocated; i++)
389 		__free_page(pages[i]);
390 
391 	kfree(pages);
392 
393 	/* 0 indicates success. */
394 	return nr_allocated != map_nr_pages;
395 }
396 
397 struct test_case_desc {
398 	const char *test_name;
399 	int (*test_func)(void);
400 };
401 
402 static struct test_case_desc test_case_array[] = {
403 	{ "fix_size_alloc_test", fix_size_alloc_test },
404 	{ "full_fit_alloc_test", full_fit_alloc_test },
405 	{ "long_busy_list_alloc_test", long_busy_list_alloc_test },
406 	{ "random_size_alloc_test", random_size_alloc_test },
407 	{ "fix_align_alloc_test", fix_align_alloc_test },
408 	{ "random_size_align_alloc_test", random_size_align_alloc_test },
409 	{ "align_shift_alloc_test", align_shift_alloc_test },
410 	{ "pcpu_alloc_test", pcpu_alloc_test },
411 	{ "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test },
412 	{ "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test },
413 	{ "vm_map_ram_test", vm_map_ram_test },
414 	/* Add a new test case here. */
415 };
416 
417 struct test_case_data {
418 	int test_failed;
419 	int test_passed;
420 	u64 time;
421 };
422 
423 static struct test_driver {
424 	struct task_struct *task;
425 	struct test_case_data data[ARRAY_SIZE(test_case_array)];
426 
427 	unsigned long start;
428 	unsigned long stop;
429 } *tdriver;
430 
shuffle_array(int * arr,int n)431 static void shuffle_array(int *arr, int n)
432 {
433 	int i, j;
434 
435 	for (i = n - 1; i > 0; i--)  {
436 		/* Cut the range. */
437 		j = get_random_u32_below(i);
438 
439 		/* Swap indexes. */
440 		swap(arr[i], arr[j]);
441 	}
442 }
443 
test_func(void * private)444 static int test_func(void *private)
445 {
446 	struct test_driver *t = private;
447 	int random_array[ARRAY_SIZE(test_case_array)];
448 	int index, i, j;
449 	ktime_t kt;
450 	u64 delta;
451 
452 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
453 		random_array[i] = i;
454 
455 	if (!sequential_test_order)
456 		shuffle_array(random_array, ARRAY_SIZE(test_case_array));
457 
458 	/*
459 	 * Block until initialization is done.
460 	 */
461 	down_read(&prepare_for_test_rwsem);
462 
463 	t->start = get_cycles();
464 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
465 		index = random_array[i];
466 
467 		/*
468 		 * Skip tests if run_test_mask has been specified.
469 		 */
470 		if (!((run_test_mask & (1 << index)) >> index))
471 			continue;
472 
473 		kt = ktime_get();
474 		for (j = 0; j < test_repeat_count; j++) {
475 			if (!test_case_array[index].test_func())
476 				t->data[index].test_passed++;
477 			else
478 				t->data[index].test_failed++;
479 		}
480 
481 		/*
482 		 * Take an average time that test took.
483 		 */
484 		delta = (u64) ktime_us_delta(ktime_get(), kt);
485 		do_div(delta, (u32) test_repeat_count);
486 
487 		t->data[index].time = delta;
488 	}
489 	t->stop = get_cycles();
490 
491 	up_read(&prepare_for_test_rwsem);
492 	test_report_one_done();
493 
494 	/*
495 	 * Wait for the kthread_stop() call.
496 	 */
497 	while (!kthread_should_stop())
498 		msleep(10);
499 
500 	return 0;
501 }
502 
503 static int
init_test_configuration(void)504 init_test_configuration(void)
505 {
506 	/*
507 	 * A maximum number of workers is defined as hard-coded
508 	 * value and set to USHRT_MAX. We add such gap just in
509 	 * case and for potential heavy stressing.
510 	 */
511 	nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX);
512 
513 	/* Allocate the space for test instances. */
514 	tdriver = kvcalloc(nr_threads, sizeof(*tdriver), GFP_KERNEL);
515 	if (tdriver == NULL)
516 		return -1;
517 
518 	if (test_repeat_count <= 0)
519 		test_repeat_count = 1;
520 
521 	if (test_loop_count <= 0)
522 		test_loop_count = 1;
523 
524 	return 0;
525 }
526 
do_concurrent_test(void)527 static void do_concurrent_test(void)
528 {
529 	int i, ret;
530 
531 	/*
532 	 * Set some basic configurations plus sanity check.
533 	 */
534 	ret = init_test_configuration();
535 	if (ret < 0)
536 		return;
537 
538 	/*
539 	 * Put on hold all workers.
540 	 */
541 	down_write(&prepare_for_test_rwsem);
542 
543 	for (i = 0; i < nr_threads; i++) {
544 		struct test_driver *t = &tdriver[i];
545 
546 		t->task = kthread_run(test_func, t, "vmalloc_test/%d", i);
547 
548 		if (!IS_ERR(t->task))
549 			/* Success. */
550 			atomic_inc(&test_n_undone);
551 		else
552 			pr_err("Failed to start %d kthread\n", i);
553 	}
554 
555 	/*
556 	 * Now let the workers do their job.
557 	 */
558 	up_write(&prepare_for_test_rwsem);
559 
560 	/*
561 	 * Sleep quiet until all workers are done with 1 second
562 	 * interval. Since the test can take a lot of time we
563 	 * can run into a stack trace of the hung task. That is
564 	 * why we go with completion_timeout and HZ value.
565 	 */
566 	do {
567 		ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
568 	} while (!ret);
569 
570 	for (i = 0; i < nr_threads; i++) {
571 		struct test_driver *t = &tdriver[i];
572 		int j;
573 
574 		if (!IS_ERR(t->task))
575 			kthread_stop(t->task);
576 
577 		for (j = 0; j < ARRAY_SIZE(test_case_array); j++) {
578 			if (!((run_test_mask & (1 << j)) >> j))
579 				continue;
580 
581 			pr_info(
582 				"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
583 				test_case_array[j].test_name,
584 				t->data[j].test_passed,
585 				t->data[j].test_failed,
586 				test_repeat_count, test_loop_count,
587 				t->data[j].time);
588 		}
589 
590 		pr_info("All test took worker%d=%lu cycles\n",
591 			i, t->stop - t->start);
592 	}
593 
594 	kvfree(tdriver);
595 }
596 
vmalloc_test_init(void)597 static int vmalloc_test_init(void)
598 {
599 	do_concurrent_test();
600 	return -EAGAIN; /* Fail will directly unload the module */
601 }
602 
603 module_init(vmalloc_test_init)
604 
605 MODULE_LICENSE("GPL");
606 MODULE_AUTHOR("Uladzislau Rezki");
607 MODULE_DESCRIPTION("vmalloc test module");
608