xref: /openbmc/linux/lib/test_vmalloc.c (revision 20e2fc42)
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 
19 #define __param(type, name, init, msg)		\
20 	static type name = init;				\
21 	module_param(name, type, 0444);			\
22 	MODULE_PARM_DESC(name, msg)				\
23 
24 __param(bool, single_cpu_test, false,
25 	"Use single first online CPU to run tests");
26 
27 __param(bool, sequential_test_order, false,
28 	"Use sequential stress tests order");
29 
30 __param(int, test_repeat_count, 1,
31 	"Set test repeat counter");
32 
33 __param(int, test_loop_count, 1000000,
34 	"Set test loop counter");
35 
36 __param(int, run_test_mask, INT_MAX,
37 	"Set tests specified in the mask.\n\n"
38 		"\t\tid: 1,   name: fix_size_alloc_test\n"
39 		"\t\tid: 2,   name: full_fit_alloc_test\n"
40 		"\t\tid: 4,   name: long_busy_list_alloc_test\n"
41 		"\t\tid: 8,   name: random_size_alloc_test\n"
42 		"\t\tid: 16,  name: fix_align_alloc_test\n"
43 		"\t\tid: 32,  name: random_size_align_alloc_test\n"
44 		"\t\tid: 64,  name: align_shift_alloc_test\n"
45 		"\t\tid: 128, name: pcpu_alloc_test\n"
46 		/* Add a new test case description here. */
47 );
48 
49 /*
50  * Depends on single_cpu_test parameter. If it is true, then
51  * use first online CPU to trigger a test on, otherwise go with
52  * all online CPUs.
53  */
54 static cpumask_t cpus_run_test_mask = CPU_MASK_NONE;
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_range(size, align,
95 		   VMALLOC_START, VMALLOC_END,
96 		   GFP_KERNEL | __GFP_ZERO,
97 		   PAGE_KERNEL,
98 		   0, 0, __builtin_return_address(0));
99 
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_range(PAGE_SIZE, align,
122 			VMALLOC_START, VMALLOC_END,
123 			GFP_KERNEL | __GFP_ZERO,
124 			PAGE_KERNEL,
125 			0, 0, __builtin_return_address(0));
126 
127 		if (!ptr)
128 			return -1;
129 
130 		vfree(ptr);
131 	}
132 
133 	return 0;
134 }
135 
136 static int fix_align_alloc_test(void)
137 {
138 	void *ptr;
139 	int i;
140 
141 	for (i = 0; i < test_loop_count; i++) {
142 		ptr = __vmalloc_node_range(5 * PAGE_SIZE,
143 			THREAD_ALIGN << 1,
144 			VMALLOC_START, VMALLOC_END,
145 			GFP_KERNEL | __GFP_ZERO,
146 			PAGE_KERNEL,
147 			0, 0, __builtin_return_address(0));
148 
149 		if (!ptr)
150 			return -1;
151 
152 		vfree(ptr);
153 	}
154 
155 	return 0;
156 }
157 
158 static int random_size_alloc_test(void)
159 {
160 	unsigned int n;
161 	void *p;
162 	int i;
163 
164 	for (i = 0; i < test_loop_count; i++) {
165 		get_random_bytes(&n, sizeof(i));
166 		n = (n % 100) + 1;
167 
168 		p = vmalloc(n * PAGE_SIZE);
169 
170 		if (!p)
171 			return -1;
172 
173 		*((__u8 *)p) = 1;
174 		vfree(p);
175 	}
176 
177 	return 0;
178 }
179 
180 static int long_busy_list_alloc_test(void)
181 {
182 	void *ptr_1, *ptr_2;
183 	void **ptr;
184 	int rv = -1;
185 	int i;
186 
187 	ptr = vmalloc(sizeof(void *) * 15000);
188 	if (!ptr)
189 		return rv;
190 
191 	for (i = 0; i < 15000; i++)
192 		ptr[i] = vmalloc(1 * PAGE_SIZE);
193 
194 	for (i = 0; i < test_loop_count; i++) {
195 		ptr_1 = vmalloc(100 * PAGE_SIZE);
196 		if (!ptr_1)
197 			goto leave;
198 
199 		ptr_2 = vmalloc(1 * PAGE_SIZE);
200 		if (!ptr_2) {
201 			vfree(ptr_1);
202 			goto leave;
203 		}
204 
205 		*((__u8 *)ptr_1) = 0;
206 		*((__u8 *)ptr_2) = 1;
207 
208 		vfree(ptr_1);
209 		vfree(ptr_2);
210 	}
211 
212 	/*  Success */
213 	rv = 0;
214 
215 leave:
216 	for (i = 0; i < 15000; i++)
217 		vfree(ptr[i]);
218 
219 	vfree(ptr);
220 	return rv;
221 }
222 
223 static int full_fit_alloc_test(void)
224 {
225 	void **ptr, **junk_ptr, *tmp;
226 	int junk_length;
227 	int rv = -1;
228 	int i;
229 
230 	junk_length = fls(num_online_cpus());
231 	junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
232 
233 	ptr = vmalloc(sizeof(void *) * junk_length);
234 	if (!ptr)
235 		return rv;
236 
237 	junk_ptr = vmalloc(sizeof(void *) * junk_length);
238 	if (!junk_ptr) {
239 		vfree(ptr);
240 		return rv;
241 	}
242 
243 	for (i = 0; i < junk_length; i++) {
244 		ptr[i] = vmalloc(1 * PAGE_SIZE);
245 		junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
246 	}
247 
248 	for (i = 0; i < junk_length; i++)
249 		vfree(junk_ptr[i]);
250 
251 	for (i = 0; i < test_loop_count; i++) {
252 		tmp = vmalloc(1 * PAGE_SIZE);
253 
254 		if (!tmp)
255 			goto error;
256 
257 		*((__u8 *)tmp) = 1;
258 		vfree(tmp);
259 	}
260 
261 	/* Success */
262 	rv = 0;
263 
264 error:
265 	for (i = 0; i < junk_length; i++)
266 		vfree(ptr[i]);
267 
268 	vfree(ptr);
269 	vfree(junk_ptr);
270 
271 	return rv;
272 }
273 
274 static int fix_size_alloc_test(void)
275 {
276 	void *ptr;
277 	int i;
278 
279 	for (i = 0; i < test_loop_count; i++) {
280 		ptr = vmalloc(3 * PAGE_SIZE);
281 
282 		if (!ptr)
283 			return -1;
284 
285 		*((__u8 *)ptr) = 0;
286 
287 		vfree(ptr);
288 	}
289 
290 	return 0;
291 }
292 
293 static int
294 pcpu_alloc_test(void)
295 {
296 	int rv = 0;
297 #ifndef CONFIG_NEED_PER_CPU_KM
298 	void __percpu **pcpu;
299 	size_t size, align;
300 	int i;
301 
302 	pcpu = vmalloc(sizeof(void __percpu *) * 35000);
303 	if (!pcpu)
304 		return -1;
305 
306 	for (i = 0; i < 35000; i++) {
307 		unsigned int r;
308 
309 		get_random_bytes(&r, sizeof(i));
310 		size = (r % (PAGE_SIZE / 4)) + 1;
311 
312 		/*
313 		 * Maximum PAGE_SIZE
314 		 */
315 		get_random_bytes(&r, sizeof(i));
316 		align = 1 << ((i % 11) + 1);
317 
318 		pcpu[i] = __alloc_percpu(size, align);
319 		if (!pcpu[i])
320 			rv = -1;
321 	}
322 
323 	for (i = 0; i < 35000; i++)
324 		free_percpu(pcpu[i]);
325 
326 	vfree(pcpu);
327 #endif
328 	return rv;
329 }
330 
331 struct test_case_desc {
332 	const char *test_name;
333 	int (*test_func)(void);
334 };
335 
336 static struct test_case_desc test_case_array[] = {
337 	{ "fix_size_alloc_test", fix_size_alloc_test },
338 	{ "full_fit_alloc_test", full_fit_alloc_test },
339 	{ "long_busy_list_alloc_test", long_busy_list_alloc_test },
340 	{ "random_size_alloc_test", random_size_alloc_test },
341 	{ "fix_align_alloc_test", fix_align_alloc_test },
342 	{ "random_size_align_alloc_test", random_size_align_alloc_test },
343 	{ "align_shift_alloc_test", align_shift_alloc_test },
344 	{ "pcpu_alloc_test", pcpu_alloc_test },
345 	/* Add a new test case here. */
346 };
347 
348 struct test_case_data {
349 	int test_failed;
350 	int test_passed;
351 	u64 time;
352 };
353 
354 /* Split it to get rid of: WARNING: line over 80 characters */
355 static struct test_case_data
356 	per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
357 
358 static struct test_driver {
359 	struct task_struct *task;
360 	unsigned long start;
361 	unsigned long stop;
362 	int cpu;
363 } per_cpu_test_driver[NR_CPUS];
364 
365 static void shuffle_array(int *arr, int n)
366 {
367 	unsigned int rnd;
368 	int i, j, x;
369 
370 	for (i = n - 1; i > 0; i--)  {
371 		get_random_bytes(&rnd, sizeof(rnd));
372 
373 		/* Cut the range. */
374 		j = rnd % i;
375 
376 		/* Swap indexes. */
377 		x = arr[i];
378 		arr[i] = arr[j];
379 		arr[j] = x;
380 	}
381 }
382 
383 static int test_func(void *private)
384 {
385 	struct test_driver *t = private;
386 	int random_array[ARRAY_SIZE(test_case_array)];
387 	int index, i, j;
388 	ktime_t kt;
389 	u64 delta;
390 
391 	if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
392 		pr_err("Failed to set affinity to %d CPU\n", t->cpu);
393 
394 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
395 		random_array[i] = i;
396 
397 	if (!sequential_test_order)
398 		shuffle_array(random_array, ARRAY_SIZE(test_case_array));
399 
400 	/*
401 	 * Block until initialization is done.
402 	 */
403 	down_read(&prepare_for_test_rwsem);
404 
405 	t->start = get_cycles();
406 	for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
407 		index = random_array[i];
408 
409 		/*
410 		 * Skip tests if run_test_mask has been specified.
411 		 */
412 		if (!((run_test_mask & (1 << index)) >> index))
413 			continue;
414 
415 		kt = ktime_get();
416 		for (j = 0; j < test_repeat_count; j++) {
417 			if (!test_case_array[index].test_func())
418 				per_cpu_test_data[t->cpu][index].test_passed++;
419 			else
420 				per_cpu_test_data[t->cpu][index].test_failed++;
421 		}
422 
423 		/*
424 		 * Take an average time that test took.
425 		 */
426 		delta = (u64) ktime_us_delta(ktime_get(), kt);
427 		do_div(delta, (u32) test_repeat_count);
428 
429 		per_cpu_test_data[t->cpu][index].time = delta;
430 	}
431 	t->stop = get_cycles();
432 
433 	up_read(&prepare_for_test_rwsem);
434 	test_report_one_done();
435 
436 	/*
437 	 * Wait for the kthread_stop() call.
438 	 */
439 	while (!kthread_should_stop())
440 		msleep(10);
441 
442 	return 0;
443 }
444 
445 static void
446 init_test_configurtion(void)
447 {
448 	/*
449 	 * Reset all data of all CPUs.
450 	 */
451 	memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
452 
453 	if (single_cpu_test)
454 		cpumask_set_cpu(cpumask_first(cpu_online_mask),
455 			&cpus_run_test_mask);
456 	else
457 		cpumask_and(&cpus_run_test_mask, cpu_online_mask,
458 			cpu_online_mask);
459 
460 	if (test_repeat_count <= 0)
461 		test_repeat_count = 1;
462 
463 	if (test_loop_count <= 0)
464 		test_loop_count = 1;
465 }
466 
467 static void do_concurrent_test(void)
468 {
469 	int cpu, ret;
470 
471 	/*
472 	 * Set some basic configurations plus sanity check.
473 	 */
474 	init_test_configurtion();
475 
476 	/*
477 	 * Put on hold all workers.
478 	 */
479 	down_write(&prepare_for_test_rwsem);
480 
481 	for_each_cpu(cpu, &cpus_run_test_mask) {
482 		struct test_driver *t = &per_cpu_test_driver[cpu];
483 
484 		t->cpu = cpu;
485 		t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
486 
487 		if (!IS_ERR(t->task))
488 			/* Success. */
489 			atomic_inc(&test_n_undone);
490 		else
491 			pr_err("Failed to start kthread for %d CPU\n", cpu);
492 	}
493 
494 	/*
495 	 * Now let the workers do their job.
496 	 */
497 	up_write(&prepare_for_test_rwsem);
498 
499 	/*
500 	 * Sleep quiet until all workers are done with 1 second
501 	 * interval. Since the test can take a lot of time we
502 	 * can run into a stack trace of the hung task. That is
503 	 * why we go with completion_timeout and HZ value.
504 	 */
505 	do {
506 		ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
507 	} while (!ret);
508 
509 	for_each_cpu(cpu, &cpus_run_test_mask) {
510 		struct test_driver *t = &per_cpu_test_driver[cpu];
511 		int i;
512 
513 		if (!IS_ERR(t->task))
514 			kthread_stop(t->task);
515 
516 		for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
517 			if (!((run_test_mask & (1 << i)) >> i))
518 				continue;
519 
520 			pr_info(
521 				"Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
522 				test_case_array[i].test_name,
523 				per_cpu_test_data[cpu][i].test_passed,
524 				per_cpu_test_data[cpu][i].test_failed,
525 				test_repeat_count, test_loop_count,
526 				per_cpu_test_data[cpu][i].time);
527 		}
528 
529 		pr_info("All test took CPU%d=%lu cycles\n",
530 			cpu, t->stop - t->start);
531 	}
532 }
533 
534 static int vmalloc_test_init(void)
535 {
536 	do_concurrent_test();
537 	return -EAGAIN; /* Fail will directly unload the module */
538 }
539 
540 static void vmalloc_test_exit(void)
541 {
542 }
543 
544 module_init(vmalloc_test_init)
545 module_exit(vmalloc_test_exit)
546 
547 MODULE_LICENSE("GPL");
548 MODULE_AUTHOR("Uladzislau Rezki");
549 MODULE_DESCRIPTION("vmalloc test module");
550