projects/linux·blob v5.8-rc2 · refs

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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) <[email protected]>
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 */
54static 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 */
60static DECLARE_RWSEM(prepare_for_test_rwsem);
61
62/*
63 * Completion tracking for worker threads.
64 */
65static DECLARE_COMPLETION(test_all_done_comp);
66static atomic_t test_n_undone = ATOMIC_INIT(0);
67
68static inline void
69test_report_one_done(void)
70{
71 if (atomic_dec_and_test(&test_n_undone))
72 complete(&test_all_done_comp);
73}
74
75static 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(size, align, GFP_KERNEL | __GFP_ZERO, 0,
95 __builtin_return_address(0));
96 if (!ptr)
97 return -1;
98
99 vfree(ptr);
100 }
101
102 return 0;
103}
104
105/*
106 * This test case is supposed to be failed.
107 */
108static int align_shift_alloc_test(void)
109{
110 unsigned long align;
111 void *ptr;
112 int i;
113
114 for (i = 0; i < BITS_PER_LONG; i++) {
115 align = ((unsigned long) 1) << i;
116
117 ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0,
118 __builtin_return_address(0));
119 if (!ptr)
120 return -1;
121
122 vfree(ptr);
123 }
124
125 return 0;
126}
127
128static int fix_align_alloc_test(void)
129{
130 void *ptr;
131 int i;
132
133 for (i = 0; i < test_loop_count; i++) {
134 ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1,
135 GFP_KERNEL | __GFP_ZERO, 0,
136 __builtin_return_address(0));
137 if (!ptr)
138 return -1;
139
140 vfree(ptr);
141 }
142
143 return 0;
144}
145
146static int random_size_alloc_test(void)
147{
148 unsigned int n;
149 void *p;
150 int i;
151
152 for (i = 0; i < test_loop_count; i++) {
153 get_random_bytes(&n, sizeof(i));
154 n = (n % 100) + 1;
155
156 p = vmalloc(n * PAGE_SIZE);
157
158 if (!p)
159 return -1;
160
161 *((__u8 *)p) = 1;
162 vfree(p);
163 }
164
165 return 0;
166}
167
168static int long_busy_list_alloc_test(void)
169{
170 void *ptr_1, *ptr_2;
171 void **ptr;
172 int rv = -1;
173 int i;
174
175 ptr = vmalloc(sizeof(void *) * 15000);
176 if (!ptr)
177 return rv;
178
179 for (i = 0; i < 15000; i++)
180 ptr[i] = vmalloc(1 * PAGE_SIZE);
181
182 for (i = 0; i < test_loop_count; i++) {
183 ptr_1 = vmalloc(100 * PAGE_SIZE);
184 if (!ptr_1)
185 goto leave;
186
187 ptr_2 = vmalloc(1 * PAGE_SIZE);
188 if (!ptr_2) {
189 vfree(ptr_1);
190 goto leave;
191 }
192
193 *((__u8 *)ptr_1) = 0;
194 *((__u8 *)ptr_2) = 1;
195
196 vfree(ptr_1);
197 vfree(ptr_2);
198 }
199
200 /* Success */
201 rv = 0;
202
203leave:
204 for (i = 0; i < 15000; i++)
205 vfree(ptr[i]);
206
207 vfree(ptr);
208 return rv;
209}
210
211static int full_fit_alloc_test(void)
212{
213 void **ptr, **junk_ptr, *tmp;
214 int junk_length;
215 int rv = -1;
216 int i;
217
218 junk_length = fls(num_online_cpus());
219 junk_length *= (32 * 1024 * 1024 / PAGE_SIZE);
220
221 ptr = vmalloc(sizeof(void *) * junk_length);
222 if (!ptr)
223 return rv;
224
225 junk_ptr = vmalloc(sizeof(void *) * junk_length);
226 if (!junk_ptr) {
227 vfree(ptr);
228 return rv;
229 }
230
231 for (i = 0; i < junk_length; i++) {
232 ptr[i] = vmalloc(1 * PAGE_SIZE);
233 junk_ptr[i] = vmalloc(1 * PAGE_SIZE);
234 }
235
236 for (i = 0; i < junk_length; i++)
237 vfree(junk_ptr[i]);
238
239 for (i = 0; i < test_loop_count; i++) {
240 tmp = vmalloc(1 * PAGE_SIZE);
241
242 if (!tmp)
243 goto error;
244
245 *((__u8 *)tmp) = 1;
246 vfree(tmp);
247 }
248
249 /* Success */
250 rv = 0;
251
252error:
253 for (i = 0; i < junk_length; i++)
254 vfree(ptr[i]);
255
256 vfree(ptr);
257 vfree(junk_ptr);
258
259 return rv;
260}
261
262static int fix_size_alloc_test(void)
263{
264 void *ptr;
265 int i;
266
267 for (i = 0; i < test_loop_count; i++) {
268 ptr = vmalloc(3 * PAGE_SIZE);
269
270 if (!ptr)
271 return -1;
272
273 *((__u8 *)ptr) = 0;
274
275 vfree(ptr);
276 }
277
278 return 0;
279}
280
281static int
282pcpu_alloc_test(void)
283{
284 int rv = 0;
285#ifndef CONFIG_NEED_PER_CPU_KM
286 void __percpu **pcpu;
287 size_t size, align;
288 int i;
289
290 pcpu = vmalloc(sizeof(void __percpu *) * 35000);
291 if (!pcpu)
292 return -1;
293
294 for (i = 0; i < 35000; i++) {
295 unsigned int r;
296
297 get_random_bytes(&r, sizeof(i));
298 size = (r % (PAGE_SIZE / 4)) + 1;
299
300 /*
301 * Maximum PAGE_SIZE
302 */
303 get_random_bytes(&r, sizeof(i));
304 align = 1 << ((i % 11) + 1);
305
306 pcpu[i] = __alloc_percpu(size, align);
307 if (!pcpu[i])
308 rv = -1;
309 }
310
311 for (i = 0; i < 35000; i++)
312 free_percpu(pcpu[i]);
313
314 vfree(pcpu);
315#endif
316 return rv;
317}
318
319struct test_case_desc {
320 const char *test_name;
321 int (*test_func)(void);
322};
323
324static struct test_case_desc test_case_array[] = {
325 { "fix_size_alloc_test", fix_size_alloc_test },
326 { "full_fit_alloc_test", full_fit_alloc_test },
327 { "long_busy_list_alloc_test", long_busy_list_alloc_test },
328 { "random_size_alloc_test", random_size_alloc_test },
329 { "fix_align_alloc_test", fix_align_alloc_test },
330 { "random_size_align_alloc_test", random_size_align_alloc_test },
331 { "align_shift_alloc_test", align_shift_alloc_test },
332 { "pcpu_alloc_test", pcpu_alloc_test },
333 /* Add a new test case here. */
334};
335
336struct test_case_data {
337 int test_failed;
338 int test_passed;
339 u64 time;
340};
341
342/* Split it to get rid of: WARNING: line over 80 characters */
343static struct test_case_data
344 per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
345
346static struct test_driver {
347 struct task_struct *task;
348 unsigned long start;
349 unsigned long stop;
350 int cpu;
351} per_cpu_test_driver[NR_CPUS];
352
353static void shuffle_array(int *arr, int n)
354{
355 unsigned int rnd;
356 int i, j, x;
357
358 for (i = n - 1; i > 0; i--) {
359 get_random_bytes(&rnd, sizeof(rnd));
360
361 /* Cut the range. */
362 j = rnd % i;
363
364 /* Swap indexes. */
365 x = arr[i];
366 arr[i] = arr[j];
367 arr[j] = x;
368 }
369}
370
371static int test_func(void *private)
372{
373 struct test_driver *t = private;
374 int random_array[ARRAY_SIZE(test_case_array)];
375 int index, i, j;
376 ktime_t kt;
377 u64 delta;
378
379 if (set_cpus_allowed_ptr(current, cpumask_of(t->cpu)) < 0)
380 pr_err("Failed to set affinity to %d CPU\n", t->cpu);
381
382 for (i = 0; i < ARRAY_SIZE(test_case_array); i++)
383 random_array[i] = i;
384
385 if (!sequential_test_order)
386 shuffle_array(random_array, ARRAY_SIZE(test_case_array));
387
388 /*
389 * Block until initialization is done.
390 */
391 down_read(&prepare_for_test_rwsem);
392
393 t->start = get_cycles();
394 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
395 index = random_array[i];
396
397 /*
398 * Skip tests if run_test_mask has been specified.
399 */
400 if (!((run_test_mask & (1 << index)) >> index))
401 continue;
402
403 kt = ktime_get();
404 for (j = 0; j < test_repeat_count; j++) {
405 if (!test_case_array[index].test_func())
406 per_cpu_test_data[t->cpu][index].test_passed++;
407 else
408 per_cpu_test_data[t->cpu][index].test_failed++;
409 }
410
411 /*
412 * Take an average time that test took.
413 */
414 delta = (u64) ktime_us_delta(ktime_get(), kt);
415 do_div(delta, (u32) test_repeat_count);
416
417 per_cpu_test_data[t->cpu][index].time = delta;
418 }
419 t->stop = get_cycles();
420
421 up_read(&prepare_for_test_rwsem);
422 test_report_one_done();
423
424 /*
425 * Wait for the kthread_stop() call.
426 */
427 while (!kthread_should_stop())
428 msleep(10);
429
430 return 0;
431}
432
433static void
434init_test_configurtion(void)
435{
436 /*
437 * Reset all data of all CPUs.
438 */
439 memset(per_cpu_test_data, 0, sizeof(per_cpu_test_data));
440
441 if (single_cpu_test)
442 cpumask_set_cpu(cpumask_first(cpu_online_mask),
443 &cpus_run_test_mask);
444 else
445 cpumask_and(&cpus_run_test_mask, cpu_online_mask,
446 cpu_online_mask);
447
448 if (test_repeat_count <= 0)
449 test_repeat_count = 1;
450
451 if (test_loop_count <= 0)
452 test_loop_count = 1;
453}
454
455static void do_concurrent_test(void)
456{
457 int cpu, ret;
458
459 /*
460 * Set some basic configurations plus sanity check.
461 */
462 init_test_configurtion();
463
464 /*
465 * Put on hold all workers.
466 */
467 down_write(&prepare_for_test_rwsem);
468
469 for_each_cpu(cpu, &cpus_run_test_mask) {
470 struct test_driver *t = &per_cpu_test_driver[cpu];
471
472 t->cpu = cpu;
473 t->task = kthread_run(test_func, t, "vmalloc_test/%d", cpu);
474
475 if (!IS_ERR(t->task))
476 /* Success. */
477 atomic_inc(&test_n_undone);
478 else
479 pr_err("Failed to start kthread for %d CPU\n", cpu);
480 }
481
482 /*
483 * Now let the workers do their job.
484 */
485 up_write(&prepare_for_test_rwsem);
486
487 /*
488 * Sleep quiet until all workers are done with 1 second
489 * interval. Since the test can take a lot of time we
490 * can run into a stack trace of the hung task. That is
491 * why we go with completion_timeout and HZ value.
492 */
493 do {
494 ret = wait_for_completion_timeout(&test_all_done_comp, HZ);
495 } while (!ret);
496
497 for_each_cpu(cpu, &cpus_run_test_mask) {
498 struct test_driver *t = &per_cpu_test_driver[cpu];
499 int i;
500
501 if (!IS_ERR(t->task))
502 kthread_stop(t->task);
503
504 for (i = 0; i < ARRAY_SIZE(test_case_array); i++) {
505 if (!((run_test_mask & (1 << i)) >> i))
506 continue;
507
508 pr_info(
509 "Summary: %s passed: %d failed: %d repeat: %d loops: %d avg: %llu usec\n",
510 test_case_array[i].test_name,
511 per_cpu_test_data[cpu][i].test_passed,
512 per_cpu_test_data[cpu][i].test_failed,
513 test_repeat_count, test_loop_count,
514 per_cpu_test_data[cpu][i].time);
515 }
516
517 pr_info("All test took CPU%d=%lu cycles\n",
518 cpu, t->stop - t->start);
519 }
520}
521
522static int vmalloc_test_init(void)
523{
524 do_concurrent_test();
525 return -EAGAIN; /* Fail will directly unload the module */
526}
527
528static void vmalloc_test_exit(void)
529{
530}
531
532module_init(vmalloc_test_init)
533module_exit(vmalloc_test_exit)
534
535MODULE_LICENSE("GPL");
536MODULE_AUTHOR("Uladzislau Rezki");
537MODULE_DESCRIPTION("vmalloc test module");