1 // SPDX-License-Identifier: GPL-2.0
2
3 /*
4 * Test module for lockless object pool
5 *
6 * Copyright: wuqiang.matt@bytedance.com
7 */
8
9 #include <linux/errno.h>
10 #include <linux/module.h>
11 #include <linux/moduleparam.h>
12 #include <linux/completion.h>
13 #include <linux/kthread.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16 #include <linux/delay.h>
17 #include <linux/hrtimer.h>
18 #include <linux/objpool.h>
19
20 #define OT_NR_MAX_BULK (16)
21
22 /* memory usage */
23 struct ot_mem_stat {
24 atomic_long_t alloc;
25 atomic_long_t free;
26 };
27
28 /* object allocation results */
29 struct ot_obj_stat {
30 unsigned long nhits;
31 unsigned long nmiss;
32 };
33
34 /* control & results per testcase */
35 struct ot_data {
36 struct rw_semaphore start;
37 struct completion wait;
38 struct completion rcu;
39 atomic_t nthreads ____cacheline_aligned_in_smp;
40 atomic_t stop ____cacheline_aligned_in_smp;
41 struct ot_mem_stat kmalloc;
42 struct ot_mem_stat vmalloc;
43 struct ot_obj_stat objects;
44 u64 duration;
45 };
46
47 /* testcase */
48 struct ot_test {
49 int async; /* synchronous or asynchronous */
50 int mode; /* only mode 0 supported */
51 int objsz; /* object size */
52 int duration; /* ms */
53 int delay; /* ms */
54 int bulk_normal;
55 int bulk_irq;
56 unsigned long hrtimer; /* ms */
57 const char *name;
58 struct ot_data data;
59 };
60
61 /* per-cpu worker */
62 struct ot_item {
63 struct objpool_head *pool; /* pool head */
64 struct ot_test *test; /* test parameters */
65
66 void (*worker)(struct ot_item *item, int irq);
67
68 /* hrtimer control */
69 ktime_t hrtcycle;
70 struct hrtimer hrtimer;
71
72 int bulk[2]; /* for thread and irq */
73 int delay;
74 u32 niters;
75
76 /* summary per thread */
77 struct ot_obj_stat stat[2]; /* thread and irq */
78 u64 duration;
79 };
80
81 /*
82 * memory leakage checking
83 */
84
ot_kzalloc(struct ot_test * test,long size)85 static void *ot_kzalloc(struct ot_test *test, long size)
86 {
87 void *ptr = kzalloc(size, GFP_KERNEL);
88
89 if (ptr)
90 atomic_long_add(size, &test->data.kmalloc.alloc);
91 return ptr;
92 }
93
ot_kfree(struct ot_test * test,void * ptr,long size)94 static void ot_kfree(struct ot_test *test, void *ptr, long size)
95 {
96 if (!ptr)
97 return;
98 atomic_long_add(size, &test->data.kmalloc.free);
99 kfree(ptr);
100 }
101
ot_mem_report(struct ot_test * test)102 static void ot_mem_report(struct ot_test *test)
103 {
104 long alloc, free;
105
106 pr_info("memory allocation summary for %s\n", test->name);
107
108 alloc = atomic_long_read(&test->data.kmalloc.alloc);
109 free = atomic_long_read(&test->data.kmalloc.free);
110 pr_info(" kmalloc: %lu - %lu = %lu\n", alloc, free, alloc - free);
111
112 alloc = atomic_long_read(&test->data.vmalloc.alloc);
113 free = atomic_long_read(&test->data.vmalloc.free);
114 pr_info(" vmalloc: %lu - %lu = %lu\n", alloc, free, alloc - free);
115 }
116
117 /* user object instance */
118 struct ot_node {
119 void *owner;
120 unsigned long data;
121 unsigned long refs;
122 unsigned long payload[32];
123 };
124
125 /* user objpool manager */
126 struct ot_context {
127 struct objpool_head pool; /* objpool head */
128 struct ot_test *test; /* test parameters */
129 void *ptr; /* user pool buffer */
130 unsigned long size; /* buffer size */
131 struct rcu_head rcu;
132 };
133
134 static DEFINE_PER_CPU(struct ot_item, ot_pcup_items);
135
ot_init_data(struct ot_data * data)136 static int ot_init_data(struct ot_data *data)
137 {
138 memset(data, 0, sizeof(*data));
139 init_rwsem(&data->start);
140 init_completion(&data->wait);
141 init_completion(&data->rcu);
142 atomic_set(&data->nthreads, 1);
143
144 return 0;
145 }
146
ot_init_node(void * nod,void * context)147 static int ot_init_node(void *nod, void *context)
148 {
149 struct ot_context *sop = context;
150 struct ot_node *on = nod;
151
152 on->owner = &sop->pool;
153 return 0;
154 }
155
ot_hrtimer_handler(struct hrtimer * hrt)156 static enum hrtimer_restart ot_hrtimer_handler(struct hrtimer *hrt)
157 {
158 struct ot_item *item = container_of(hrt, struct ot_item, hrtimer);
159 struct ot_test *test = item->test;
160
161 if (atomic_read_acquire(&test->data.stop))
162 return HRTIMER_NORESTART;
163
164 /* do bulk-testings for objects pop/push */
165 item->worker(item, 1);
166
167 hrtimer_forward(hrt, hrt->base->get_time(), item->hrtcycle);
168 return HRTIMER_RESTART;
169 }
170
ot_start_hrtimer(struct ot_item * item)171 static void ot_start_hrtimer(struct ot_item *item)
172 {
173 if (!item->test->hrtimer)
174 return;
175 hrtimer_start(&item->hrtimer, item->hrtcycle, HRTIMER_MODE_REL);
176 }
177
ot_stop_hrtimer(struct ot_item * item)178 static void ot_stop_hrtimer(struct ot_item *item)
179 {
180 if (!item->test->hrtimer)
181 return;
182 hrtimer_cancel(&item->hrtimer);
183 }
184
ot_init_hrtimer(struct ot_item * item,unsigned long hrtimer)185 static int ot_init_hrtimer(struct ot_item *item, unsigned long hrtimer)
186 {
187 struct hrtimer *hrt = &item->hrtimer;
188
189 if (!hrtimer)
190 return -ENOENT;
191
192 item->hrtcycle = ktime_set(0, hrtimer * 1000000UL);
193 hrtimer_init(hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
194 hrt->function = ot_hrtimer_handler;
195 return 0;
196 }
197
ot_init_cpu_item(struct ot_item * item,struct ot_test * test,struct objpool_head * pool,void (* worker)(struct ot_item *,int))198 static int ot_init_cpu_item(struct ot_item *item,
199 struct ot_test *test,
200 struct objpool_head *pool,
201 void (*worker)(struct ot_item *, int))
202 {
203 memset(item, 0, sizeof(*item));
204 item->pool = pool;
205 item->test = test;
206 item->worker = worker;
207
208 item->bulk[0] = test->bulk_normal;
209 item->bulk[1] = test->bulk_irq;
210 item->delay = test->delay;
211
212 /* initialize hrtimer */
213 ot_init_hrtimer(item, item->test->hrtimer);
214 return 0;
215 }
216
ot_thread_worker(void * arg)217 static int ot_thread_worker(void *arg)
218 {
219 struct ot_item *item = arg;
220 struct ot_test *test = item->test;
221 ktime_t start;
222
223 atomic_inc(&test->data.nthreads);
224 down_read(&test->data.start);
225 up_read(&test->data.start);
226 start = ktime_get();
227 ot_start_hrtimer(item);
228 do {
229 if (atomic_read_acquire(&test->data.stop))
230 break;
231 /* do bulk-testings for objects pop/push */
232 item->worker(item, 0);
233 } while (!kthread_should_stop());
234 ot_stop_hrtimer(item);
235 item->duration = (u64) ktime_us_delta(ktime_get(), start);
236 if (atomic_dec_and_test(&test->data.nthreads))
237 complete(&test->data.wait);
238
239 return 0;
240 }
241
ot_perf_report(struct ot_test * test,u64 duration)242 static void ot_perf_report(struct ot_test *test, u64 duration)
243 {
244 struct ot_obj_stat total, normal = {0}, irq = {0};
245 int cpu, nthreads = 0;
246
247 pr_info("\n");
248 pr_info("Testing summary for %s\n", test->name);
249
250 for_each_possible_cpu(cpu) {
251 struct ot_item *item = per_cpu_ptr(&ot_pcup_items, cpu);
252 if (!item->duration)
253 continue;
254 normal.nhits += item->stat[0].nhits;
255 normal.nmiss += item->stat[0].nmiss;
256 irq.nhits += item->stat[1].nhits;
257 irq.nmiss += item->stat[1].nmiss;
258 pr_info("CPU: %d duration: %lluus\n", cpu, item->duration);
259 pr_info("\tthread:\t%16lu hits \t%16lu miss\n",
260 item->stat[0].nhits, item->stat[0].nmiss);
261 pr_info("\tirq: \t%16lu hits \t%16lu miss\n",
262 item->stat[1].nhits, item->stat[1].nmiss);
263 pr_info("\ttotal: \t%16lu hits \t%16lu miss\n",
264 item->stat[0].nhits + item->stat[1].nhits,
265 item->stat[0].nmiss + item->stat[1].nmiss);
266 nthreads++;
267 }
268
269 total.nhits = normal.nhits + irq.nhits;
270 total.nmiss = normal.nmiss + irq.nmiss;
271
272 pr_info("ALL: \tnthreads: %d duration: %lluus\n", nthreads, duration);
273 pr_info("SUM: \t%16lu hits \t%16lu miss\n",
274 total.nhits, total.nmiss);
275
276 test->data.objects = total;
277 test->data.duration = duration;
278 }
279
280 /*
281 * synchronous test cases for objpool manipulation
282 */
283
284 /* objpool manipulation for synchronous mode (percpu objpool) */
ot_init_sync_m0(struct ot_test * test)285 static struct ot_context *ot_init_sync_m0(struct ot_test *test)
286 {
287 struct ot_context *sop = NULL;
288 int max = num_possible_cpus() << 3;
289 gfp_t gfp = GFP_KERNEL;
290
291 sop = (struct ot_context *)ot_kzalloc(test, sizeof(*sop));
292 if (!sop)
293 return NULL;
294 sop->test = test;
295 if (test->objsz < 512)
296 gfp = GFP_ATOMIC;
297
298 if (objpool_init(&sop->pool, max, test->objsz,
299 gfp, sop, ot_init_node, NULL)) {
300 ot_kfree(test, sop, sizeof(*sop));
301 return NULL;
302 }
303 WARN_ON(max != sop->pool.nr_objs);
304
305 return sop;
306 }
307
ot_fini_sync(struct ot_context * sop)308 static void ot_fini_sync(struct ot_context *sop)
309 {
310 objpool_fini(&sop->pool);
311 ot_kfree(sop->test, sop, sizeof(*sop));
312 }
313
314 static struct {
315 struct ot_context * (*init)(struct ot_test *oc);
316 void (*fini)(struct ot_context *sop);
317 } g_ot_sync_ops[] = {
318 {.init = ot_init_sync_m0, .fini = ot_fini_sync},
319 };
320
321 /*
322 * synchronous test cases: performance mode
323 */
324
ot_bulk_sync(struct ot_item * item,int irq)325 static void ot_bulk_sync(struct ot_item *item, int irq)
326 {
327 struct ot_node *nods[OT_NR_MAX_BULK];
328 int i;
329
330 for (i = 0; i < item->bulk[irq]; i++)
331 nods[i] = objpool_pop(item->pool);
332
333 if (!irq && (item->delay || !(++(item->niters) & 0x7FFF)))
334 msleep(item->delay);
335
336 while (i-- > 0) {
337 struct ot_node *on = nods[i];
338 if (on) {
339 on->refs++;
340 objpool_push(on, item->pool);
341 item->stat[irq].nhits++;
342 } else {
343 item->stat[irq].nmiss++;
344 }
345 }
346 }
347
ot_start_sync(struct ot_test * test)348 static int ot_start_sync(struct ot_test *test)
349 {
350 struct ot_context *sop;
351 ktime_t start;
352 u64 duration;
353 unsigned long timeout;
354 int cpu;
355
356 /* initialize objpool for syncrhonous testcase */
357 sop = g_ot_sync_ops[test->mode].init(test);
358 if (!sop)
359 return -ENOMEM;
360
361 /* grab rwsem to block testing threads */
362 down_write(&test->data.start);
363
364 for_each_possible_cpu(cpu) {
365 struct ot_item *item = per_cpu_ptr(&ot_pcup_items, cpu);
366 struct task_struct *work;
367
368 ot_init_cpu_item(item, test, &sop->pool, ot_bulk_sync);
369
370 /* skip offline cpus */
371 if (!cpu_online(cpu))
372 continue;
373
374 work = kthread_create_on_node(ot_thread_worker, item,
375 cpu_to_node(cpu), "ot_worker_%d", cpu);
376 if (IS_ERR(work)) {
377 pr_err("failed to create thread for cpu %d\n", cpu);
378 } else {
379 kthread_bind(work, cpu);
380 wake_up_process(work);
381 }
382 }
383
384 /* wait a while to make sure all threads waiting at start line */
385 msleep(20);
386
387 /* in case no threads were created: memory insufficient ? */
388 if (atomic_dec_and_test(&test->data.nthreads))
389 complete(&test->data.wait);
390
391 // sched_set_fifo_low(current);
392
393 /* start objpool testing threads */
394 start = ktime_get();
395 up_write(&test->data.start);
396
397 /* yeild cpu to worker threads for duration ms */
398 timeout = msecs_to_jiffies(test->duration);
399 schedule_timeout_interruptible(timeout);
400
401 /* tell workers threads to quit */
402 atomic_set_release(&test->data.stop, 1);
403
404 /* wait all workers threads finish and quit */
405 wait_for_completion(&test->data.wait);
406 duration = (u64) ktime_us_delta(ktime_get(), start);
407
408 /* cleanup objpool */
409 g_ot_sync_ops[test->mode].fini(sop);
410
411 /* report testing summary and performance results */
412 ot_perf_report(test, duration);
413
414 /* report memory allocation summary */
415 ot_mem_report(test);
416
417 return 0;
418 }
419
420 /*
421 * asynchronous test cases: pool lifecycle controlled by refcount
422 */
423
ot_fini_async_rcu(struct rcu_head * rcu)424 static void ot_fini_async_rcu(struct rcu_head *rcu)
425 {
426 struct ot_context *sop = container_of(rcu, struct ot_context, rcu);
427 struct ot_test *test = sop->test;
428
429 /* here all cpus are aware of the stop event: test->data.stop = 1 */
430 WARN_ON(!atomic_read_acquire(&test->data.stop));
431
432 objpool_fini(&sop->pool);
433 complete(&test->data.rcu);
434 }
435
ot_fini_async(struct ot_context * sop)436 static void ot_fini_async(struct ot_context *sop)
437 {
438 /* make sure the stop event is acknowledged by all cores */
439 call_rcu(&sop->rcu, ot_fini_async_rcu);
440 }
441
ot_objpool_release(struct objpool_head * head,void * context)442 static int ot_objpool_release(struct objpool_head *head, void *context)
443 {
444 struct ot_context *sop = context;
445
446 WARN_ON(!head || !sop || head != &sop->pool);
447
448 /* do context cleaning if needed */
449 if (sop)
450 ot_kfree(sop->test, sop, sizeof(*sop));
451
452 return 0;
453 }
454
ot_init_async_m0(struct ot_test * test)455 static struct ot_context *ot_init_async_m0(struct ot_test *test)
456 {
457 struct ot_context *sop = NULL;
458 int max = num_possible_cpus() << 3;
459 gfp_t gfp = GFP_KERNEL;
460
461 sop = (struct ot_context *)ot_kzalloc(test, sizeof(*sop));
462 if (!sop)
463 return NULL;
464 sop->test = test;
465 if (test->objsz < 512)
466 gfp = GFP_ATOMIC;
467
468 if (objpool_init(&sop->pool, max, test->objsz, gfp, sop,
469 ot_init_node, ot_objpool_release)) {
470 ot_kfree(test, sop, sizeof(*sop));
471 return NULL;
472 }
473 WARN_ON(max != sop->pool.nr_objs);
474
475 return sop;
476 }
477
478 static struct {
479 struct ot_context * (*init)(struct ot_test *oc);
480 void (*fini)(struct ot_context *sop);
481 } g_ot_async_ops[] = {
482 {.init = ot_init_async_m0, .fini = ot_fini_async},
483 };
484
ot_nod_recycle(struct ot_node * on,struct objpool_head * pool,int release)485 static void ot_nod_recycle(struct ot_node *on, struct objpool_head *pool,
486 int release)
487 {
488 struct ot_context *sop;
489
490 on->refs++;
491
492 if (!release) {
493 /* push object back to opjpool for reuse */
494 objpool_push(on, pool);
495 return;
496 }
497
498 sop = container_of(pool, struct ot_context, pool);
499 WARN_ON(sop != pool->context);
500
501 /* unref objpool with nod removed forever */
502 objpool_drop(on, pool);
503 }
504
ot_bulk_async(struct ot_item * item,int irq)505 static void ot_bulk_async(struct ot_item *item, int irq)
506 {
507 struct ot_test *test = item->test;
508 struct ot_node *nods[OT_NR_MAX_BULK];
509 int i, stop;
510
511 for (i = 0; i < item->bulk[irq]; i++)
512 nods[i] = objpool_pop(item->pool);
513
514 if (!irq) {
515 if (item->delay || !(++(item->niters) & 0x7FFF))
516 msleep(item->delay);
517 get_cpu();
518 }
519
520 stop = atomic_read_acquire(&test->data.stop);
521
522 /* drop all objects and deref objpool */
523 while (i-- > 0) {
524 struct ot_node *on = nods[i];
525
526 if (on) {
527 on->refs++;
528 ot_nod_recycle(on, item->pool, stop);
529 item->stat[irq].nhits++;
530 } else {
531 item->stat[irq].nmiss++;
532 }
533 }
534
535 if (!irq)
536 put_cpu();
537 }
538
ot_start_async(struct ot_test * test)539 static int ot_start_async(struct ot_test *test)
540 {
541 struct ot_context *sop;
542 ktime_t start;
543 u64 duration;
544 unsigned long timeout;
545 int cpu;
546
547 /* initialize objpool for syncrhonous testcase */
548 sop = g_ot_async_ops[test->mode].init(test);
549 if (!sop)
550 return -ENOMEM;
551
552 /* grab rwsem to block testing threads */
553 down_write(&test->data.start);
554
555 for_each_possible_cpu(cpu) {
556 struct ot_item *item = per_cpu_ptr(&ot_pcup_items, cpu);
557 struct task_struct *work;
558
559 ot_init_cpu_item(item, test, &sop->pool, ot_bulk_async);
560
561 /* skip offline cpus */
562 if (!cpu_online(cpu))
563 continue;
564
565 work = kthread_create_on_node(ot_thread_worker, item,
566 cpu_to_node(cpu), "ot_worker_%d", cpu);
567 if (IS_ERR(work)) {
568 pr_err("failed to create thread for cpu %d\n", cpu);
569 } else {
570 kthread_bind(work, cpu);
571 wake_up_process(work);
572 }
573 }
574
575 /* wait a while to make sure all threads waiting at start line */
576 msleep(20);
577
578 /* in case no threads were created: memory insufficient ? */
579 if (atomic_dec_and_test(&test->data.nthreads))
580 complete(&test->data.wait);
581
582 /* start objpool testing threads */
583 start = ktime_get();
584 up_write(&test->data.start);
585
586 /* yeild cpu to worker threads for duration ms */
587 timeout = msecs_to_jiffies(test->duration);
588 schedule_timeout_interruptible(timeout);
589
590 /* tell workers threads to quit */
591 atomic_set_release(&test->data.stop, 1);
592
593 /* do async-finalization */
594 g_ot_async_ops[test->mode].fini(sop);
595
596 /* wait all workers threads finish and quit */
597 wait_for_completion(&test->data.wait);
598 duration = (u64) ktime_us_delta(ktime_get(), start);
599
600 /* assure rcu callback is triggered */
601 wait_for_completion(&test->data.rcu);
602
603 /*
604 * now we are sure that objpool is finalized either
605 * by rcu callback or by worker threads
606 */
607
608 /* report testing summary and performance results */
609 ot_perf_report(test, duration);
610
611 /* report memory allocation summary */
612 ot_mem_report(test);
613
614 return 0;
615 }
616
617 /*
618 * predefined testing cases:
619 * synchronous case / overrun case / async case
620 *
621 * async: synchronous or asynchronous testing
622 * mode: only mode 0 supported
623 * objsz: object size
624 * duration: int, total test time in ms
625 * delay: int, delay (in ms) between each iteration
626 * bulk_normal: int, repeat times for thread worker
627 * bulk_irq: int, repeat times for irq consumer
628 * hrtimer: unsigned long, hrtimer intervnal in ms
629 * name: char *, tag for current test ot_item
630 */
631
632 #define NODE_COMPACT sizeof(struct ot_node)
633 #define NODE_VMALLOC (512)
634
635 static struct ot_test g_testcases[] = {
636
637 /* sync & normal */
638 {0, 0, NODE_COMPACT, 1000, 0, 1, 0, 0, "sync: percpu objpool"},
639 {0, 0, NODE_VMALLOC, 1000, 0, 1, 0, 0, "sync: percpu objpool from vmalloc"},
640
641 /* sync & hrtimer */
642 {0, 0, NODE_COMPACT, 1000, 0, 1, 1, 4, "sync & hrtimer: percpu objpool"},
643 {0, 0, NODE_VMALLOC, 1000, 0, 1, 1, 4, "sync & hrtimer: percpu objpool from vmalloc"},
644
645 /* sync & overrun */
646 {0, 0, NODE_COMPACT, 1000, 0, 16, 0, 0, "sync overrun: percpu objpool"},
647 {0, 0, NODE_VMALLOC, 1000, 0, 16, 0, 0, "sync overrun: percpu objpool from vmalloc"},
648
649 /* async mode */
650 {1, 0, NODE_COMPACT, 1000, 100, 1, 0, 0, "async: percpu objpool"},
651 {1, 0, NODE_VMALLOC, 1000, 100, 1, 0, 0, "async: percpu objpool from vmalloc"},
652
653 /* async + hrtimer mode */
654 {1, 0, NODE_COMPACT, 1000, 0, 4, 4, 4, "async & hrtimer: percpu objpool"},
655 {1, 0, NODE_VMALLOC, 1000, 0, 4, 4, 4, "async & hrtimer: percpu objpool from vmalloc"},
656 };
657
ot_mod_init(void)658 static int __init ot_mod_init(void)
659 {
660 int i;
661
662 /* perform testings */
663 for (i = 0; i < ARRAY_SIZE(g_testcases); i++) {
664 ot_init_data(&g_testcases[i].data);
665 if (g_testcases[i].async)
666 ot_start_async(&g_testcases[i]);
667 else
668 ot_start_sync(&g_testcases[i]);
669 }
670
671 /* show tests summary */
672 pr_info("\n");
673 pr_info("Summary of testcases:\n");
674 for (i = 0; i < ARRAY_SIZE(g_testcases); i++) {
675 pr_info(" duration: %lluus \thits: %10lu \tmiss: %10lu \t%s\n",
676 g_testcases[i].data.duration, g_testcases[i].data.objects.nhits,
677 g_testcases[i].data.objects.nmiss, g_testcases[i].name);
678 }
679
680 return -EAGAIN;
681 }
682
ot_mod_exit(void)683 static void __exit ot_mod_exit(void)
684 {
685 }
686
687 module_init(ot_mod_init);
688 module_exit(ot_mod_exit);
689
690 MODULE_DESCRIPTION("Test module for lockless object pool");
691 MODULE_LICENSE("GPL");
692