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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) <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 */
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_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 */
112static 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
136static 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
158static 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
180static 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
215leave:
216 for (i = 0; i < 15000; i++)
217 vfree(ptr[i]);
218
219 vfree(ptr);
220 return rv;
221}
222
223static 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
264error:
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
274static 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
293static int
294pcpu_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
331struct test_case_desc {
332 const char *test_name;
333 int (*test_func)(void);
334};
335
336static 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
348struct 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 */
355static struct test_case_data
356 per_cpu_test_data[NR_CPUS][ARRAY_SIZE(test_case_array)];
357
358static 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
365static 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
383static 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
445static void
446init_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
467static 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
534static int vmalloc_test_init(void)
535{
536 do_concurrent_test();
537 return -EAGAIN; /* Fail will directly unload the module */
538}
539
540static void vmalloc_test_exit(void)
541{
542}
543
544module_init(vmalloc_test_init)
545module_exit(vmalloc_test_exit)
546
547MODULE_LICENSE("GPL");
548MODULE_AUTHOR("Uladzislau Rezki");
549MODULE_DESCRIPTION("vmalloc test module");