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10#define pr_fmt(fmt) fmt
11
12#include <linux/types.h>
13#include <linux/kernel.h>
14#include <linux/init.h>
15#include <linux/mm.h>
16#include <linux/module.h>
17#include <linux/kthread.h>
18#include <linux/err.h>
19#include <linux/spinlock.h>
20#include <linux/smp.h>
21#include <linux/rcupdate.h>
22#include <linux/interrupt.h>
23#include <linux/sched.h>
24#include <uapi/linux/sched/types.h>
25#include <linux/atomic.h>
26#include <linux/bitops.h>
27#include <linux/completion.h>
28#include <linux/moduleparam.h>
29#include <linux/percpu.h>
30#include <linux/notifier.h>
31#include <linux/reboot.h>
32#include <linux/freezer.h>
33#include <linux/cpu.h>
34#include <linux/delay.h>
35#include <linux/stat.h>
36#include <linux/srcu.h>
37#include <linux/slab.h>
38#include <asm/byteorder.h>
39#include <linux/torture.h>
40#include <linux/vmalloc.h>
41
42#include "rcu.h"
43
44MODULE_LICENSE("GPL");
45MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
46
47#define PERF_FLAG "-perf:"
48#define PERFOUT_STRING(s) \
49 pr_alert("%s" PERF_FLAG " %s\n", perf_type, s)
50#define VERBOSE_PERFOUT_STRING(s) \
51 do { if (verbose) pr_alert("%s" PERF_FLAG " %s\n", perf_type, s); } while (0)
52#define VERBOSE_PERFOUT_ERRSTRING(s) \
53 do { if (verbose) pr_alert("%s" PERF_FLAG "!!! %s\n", perf_type, s); } while (0)
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73
74#ifdef MODULE
75# define RCUPERF_SHUTDOWN 0
76#else
77# define RCUPERF_SHUTDOWN 1
78#endif
79
80torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
81torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
82torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
83torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
84torture_param(int, nreaders, -1, "Number of RCU reader threads");
85torture_param(int, nwriters, -1, "Number of RCU updater threads");
86torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
87 "Shutdown at end of performance tests.");
88torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
89torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
90torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
91
92static char *perf_type = "rcu";
93module_param(perf_type, charp, 0444);
94MODULE_PARM_DESC(perf_type, "Type of RCU to performance-test (rcu, srcu, ...)");
95
96static int nrealreaders;
97static int nrealwriters;
98static struct task_struct **writer_tasks;
99static struct task_struct **reader_tasks;
100static struct task_struct *shutdown_task;
101
102static u64 **writer_durations;
103static int *writer_n_durations;
104static atomic_t n_rcu_perf_reader_started;
105static atomic_t n_rcu_perf_writer_started;
106static atomic_t n_rcu_perf_writer_finished;
107static wait_queue_head_t shutdown_wq;
108static u64 t_rcu_perf_writer_started;
109static u64 t_rcu_perf_writer_finished;
110static unsigned long b_rcu_gp_test_started;
111static unsigned long b_rcu_gp_test_finished;
112static DEFINE_PER_CPU(atomic_t, n_async_inflight);
113
114#define MAX_MEAS 10000
115#define MIN_MEAS 100
116
117
118
119
120
121struct rcu_perf_ops {
122 int ptype;
123 void (*init)(void);
124 void (*cleanup)(void);
125 int (*readlock)(void);
126 void (*readunlock)(int idx);
127 unsigned long (*get_gp_seq)(void);
128 unsigned long (*gp_diff)(unsigned long new, unsigned long old);
129 unsigned long (*exp_completed)(void);
130 void (*async)(struct rcu_head *head, rcu_callback_t func);
131 void (*gp_barrier)(void);
132 void (*sync)(void);
133 void (*exp_sync)(void);
134 const char *name;
135};
136
137static struct rcu_perf_ops *cur_ops;
138
139
140
141
142
143static int rcu_perf_read_lock(void) __acquires(RCU)
144{
145 rcu_read_lock();
146 return 0;
147}
148
149static void rcu_perf_read_unlock(int idx) __releases(RCU)
150{
151 rcu_read_unlock();
152}
153
154static unsigned long __maybe_unused rcu_no_completed(void)
155{
156 return 0;
157}
158
159static void rcu_sync_perf_init(void)
160{
161}
162
163static struct rcu_perf_ops rcu_ops = {
164 .ptype = RCU_FLAVOR,
165 .init = rcu_sync_perf_init,
166 .readlock = rcu_perf_read_lock,
167 .readunlock = rcu_perf_read_unlock,
168 .get_gp_seq = rcu_get_gp_seq,
169 .gp_diff = rcu_seq_diff,
170 .exp_completed = rcu_exp_batches_completed,
171 .async = call_rcu,
172 .gp_barrier = rcu_barrier,
173 .sync = synchronize_rcu,
174 .exp_sync = synchronize_rcu_expedited,
175 .name = "rcu"
176};
177
178
179
180
181
182DEFINE_STATIC_SRCU(srcu_ctl_perf);
183static struct srcu_struct *srcu_ctlp = &srcu_ctl_perf;
184
185static int srcu_perf_read_lock(void) __acquires(srcu_ctlp)
186{
187 return srcu_read_lock(srcu_ctlp);
188}
189
190static void srcu_perf_read_unlock(int idx) __releases(srcu_ctlp)
191{
192 srcu_read_unlock(srcu_ctlp, idx);
193}
194
195static unsigned long srcu_perf_completed(void)
196{
197 return srcu_batches_completed(srcu_ctlp);
198}
199
200static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
201{
202 call_srcu(srcu_ctlp, head, func);
203}
204
205static void srcu_rcu_barrier(void)
206{
207 srcu_barrier(srcu_ctlp);
208}
209
210static void srcu_perf_synchronize(void)
211{
212 synchronize_srcu(srcu_ctlp);
213}
214
215static void srcu_perf_synchronize_expedited(void)
216{
217 synchronize_srcu_expedited(srcu_ctlp);
218}
219
220static struct rcu_perf_ops srcu_ops = {
221 .ptype = SRCU_FLAVOR,
222 .init = rcu_sync_perf_init,
223 .readlock = srcu_perf_read_lock,
224 .readunlock = srcu_perf_read_unlock,
225 .get_gp_seq = srcu_perf_completed,
226 .gp_diff = rcu_seq_diff,
227 .exp_completed = srcu_perf_completed,
228 .async = srcu_call_rcu,
229 .gp_barrier = srcu_rcu_barrier,
230 .sync = srcu_perf_synchronize,
231 .exp_sync = srcu_perf_synchronize_expedited,
232 .name = "srcu"
233};
234
235static struct srcu_struct srcud;
236
237static void srcu_sync_perf_init(void)
238{
239 srcu_ctlp = &srcud;
240 init_srcu_struct(srcu_ctlp);
241}
242
243static void srcu_sync_perf_cleanup(void)
244{
245 cleanup_srcu_struct(srcu_ctlp);
246}
247
248static struct rcu_perf_ops srcud_ops = {
249 .ptype = SRCU_FLAVOR,
250 .init = srcu_sync_perf_init,
251 .cleanup = srcu_sync_perf_cleanup,
252 .readlock = srcu_perf_read_lock,
253 .readunlock = srcu_perf_read_unlock,
254 .get_gp_seq = srcu_perf_completed,
255 .gp_diff = rcu_seq_diff,
256 .exp_completed = srcu_perf_completed,
257 .async = srcu_call_rcu,
258 .gp_barrier = srcu_rcu_barrier,
259 .sync = srcu_perf_synchronize,
260 .exp_sync = srcu_perf_synchronize_expedited,
261 .name = "srcud"
262};
263
264
265
266
267
268static int tasks_perf_read_lock(void)
269{
270 return 0;
271}
272
273static void tasks_perf_read_unlock(int idx)
274{
275}
276
277static struct rcu_perf_ops tasks_ops = {
278 .ptype = RCU_TASKS_FLAVOR,
279 .init = rcu_sync_perf_init,
280 .readlock = tasks_perf_read_lock,
281 .readunlock = tasks_perf_read_unlock,
282 .get_gp_seq = rcu_no_completed,
283 .gp_diff = rcu_seq_diff,
284 .async = call_rcu_tasks,
285 .gp_barrier = rcu_barrier_tasks,
286 .sync = synchronize_rcu_tasks,
287 .exp_sync = synchronize_rcu_tasks,
288 .name = "tasks"
289};
290
291static unsigned long rcuperf_seq_diff(unsigned long new, unsigned long old)
292{
293 if (!cur_ops->gp_diff)
294 return new - old;
295 return cur_ops->gp_diff(new, old);
296}
297
298
299
300
301static void rcu_perf_wait_shutdown(void)
302{
303 cond_resched_tasks_rcu_qs();
304 if (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters)
305 return;
306 while (!torture_must_stop())
307 schedule_timeout_uninterruptible(1);
308}
309
310
311
312
313
314static int
315rcu_perf_reader(void *arg)
316{
317 unsigned long flags;
318 int idx;
319 long me = (long)arg;
320
321 VERBOSE_PERFOUT_STRING("rcu_perf_reader task started");
322 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
323 set_user_nice(current, MAX_NICE);
324 atomic_inc(&n_rcu_perf_reader_started);
325
326 do {
327 local_irq_save(flags);
328 idx = cur_ops->readlock();
329 cur_ops->readunlock(idx);
330 local_irq_restore(flags);
331 rcu_perf_wait_shutdown();
332 } while (!torture_must_stop());
333 torture_kthread_stopping("rcu_perf_reader");
334 return 0;
335}
336
337
338
339
340static void rcu_perf_async_cb(struct rcu_head *rhp)
341{
342 atomic_dec(this_cpu_ptr(&n_async_inflight));
343 kfree(rhp);
344}
345
346
347
348
349static int
350rcu_perf_writer(void *arg)
351{
352 int i = 0;
353 int i_max;
354 long me = (long)arg;
355 struct rcu_head *rhp = NULL;
356 struct sched_param sp;
357 bool started = false, done = false, alldone = false;
358 u64 t;
359 u64 *wdp;
360 u64 *wdpp = writer_durations[me];
361
362 VERBOSE_PERFOUT_STRING("rcu_perf_writer task started");
363 WARN_ON(!wdpp);
364 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
365 sp.sched_priority = 1;
366 sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
367
368 if (holdoff)
369 schedule_timeout_uninterruptible(holdoff * HZ);
370
371
372
373
374
375
376 while (!gp_exp && system_state != SYSTEM_RUNNING)
377 schedule_timeout_uninterruptible(1);
378
379 t = ktime_get_mono_fast_ns();
380 if (atomic_inc_return(&n_rcu_perf_writer_started) >= nrealwriters) {
381 t_rcu_perf_writer_started = t;
382 if (gp_exp) {
383 b_rcu_gp_test_started =
384 cur_ops->exp_completed() / 2;
385 } else {
386 b_rcu_gp_test_started = cur_ops->get_gp_seq();
387 }
388 }
389
390 do {
391 if (writer_holdoff)
392 udelay(writer_holdoff);
393 wdp = &wdpp[i];
394 *wdp = ktime_get_mono_fast_ns();
395 if (gp_async) {
396retry:
397 if (!rhp)
398 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
399 if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
400 atomic_inc(this_cpu_ptr(&n_async_inflight));
401 cur_ops->async(rhp, rcu_perf_async_cb);
402 rhp = NULL;
403 } else if (!kthread_should_stop()) {
404 cur_ops->gp_barrier();
405 goto retry;
406 } else {
407 kfree(rhp);
408 }
409 } else if (gp_exp) {
410 cur_ops->exp_sync();
411 } else {
412 cur_ops->sync();
413 }
414 t = ktime_get_mono_fast_ns();
415 *wdp = t - *wdp;
416 i_max = i;
417 if (!started &&
418 atomic_read(&n_rcu_perf_writer_started) >= nrealwriters)
419 started = true;
420 if (!done && i >= MIN_MEAS) {
421 done = true;
422 sp.sched_priority = 0;
423 sched_setscheduler_nocheck(current,
424 SCHED_NORMAL, &sp);
425 pr_alert("%s%s rcu_perf_writer %ld has %d measurements\n",
426 perf_type, PERF_FLAG, me, MIN_MEAS);
427 if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
428 nrealwriters) {
429 schedule_timeout_interruptible(10);
430 rcu_ftrace_dump(DUMP_ALL);
431 PERFOUT_STRING("Test complete");
432 t_rcu_perf_writer_finished = t;
433 if (gp_exp) {
434 b_rcu_gp_test_finished =
435 cur_ops->exp_completed() / 2;
436 } else {
437 b_rcu_gp_test_finished =
438 cur_ops->get_gp_seq();
439 }
440 if (shutdown) {
441 smp_mb();
442 wake_up(&shutdown_wq);
443 }
444 }
445 }
446 if (done && !alldone &&
447 atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)
448 alldone = true;
449 if (started && !alldone && i < MAX_MEAS - 1)
450 i++;
451 rcu_perf_wait_shutdown();
452 } while (!torture_must_stop());
453 if (gp_async) {
454 cur_ops->gp_barrier();
455 }
456 writer_n_durations[me] = i_max;
457 torture_kthread_stopping("rcu_perf_writer");
458 return 0;
459}
460
461static void
462rcu_perf_print_module_parms(struct rcu_perf_ops *cur_ops, const char *tag)
463{
464 pr_alert("%s" PERF_FLAG
465 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
466 perf_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
467}
468
469static void
470rcu_perf_cleanup(void)
471{
472 int i;
473 int j;
474 int ngps = 0;
475 u64 *wdp;
476 u64 *wdpp;
477
478
479
480
481
482 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
483 VERBOSE_PERFOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
484 if (rcu_gp_is_normal() && gp_exp)
485 VERBOSE_PERFOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
486 if (gp_exp && gp_async)
487 VERBOSE_PERFOUT_ERRSTRING("No expedited async GPs, so went with async!");
488
489 if (torture_cleanup_begin())
490 return;
491 if (!cur_ops) {
492 torture_cleanup_end();
493 return;
494 }
495
496 if (reader_tasks) {
497 for (i = 0; i < nrealreaders; i++)
498 torture_stop_kthread(rcu_perf_reader,
499 reader_tasks[i]);
500 kfree(reader_tasks);
501 }
502
503 if (writer_tasks) {
504 for (i = 0; i < nrealwriters; i++) {
505 torture_stop_kthread(rcu_perf_writer,
506 writer_tasks[i]);
507 if (!writer_n_durations)
508 continue;
509 j = writer_n_durations[i];
510 pr_alert("%s%s writer %d gps: %d\n",
511 perf_type, PERF_FLAG, i, j);
512 ngps += j;
513 }
514 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
515 perf_type, PERF_FLAG,
516 t_rcu_perf_writer_started, t_rcu_perf_writer_finished,
517 t_rcu_perf_writer_finished -
518 t_rcu_perf_writer_started,
519 ngps,
520 rcuperf_seq_diff(b_rcu_gp_test_finished,
521 b_rcu_gp_test_started));
522 for (i = 0; i < nrealwriters; i++) {
523 if (!writer_durations)
524 break;
525 if (!writer_n_durations)
526 continue;
527 wdpp = writer_durations[i];
528 if (!wdpp)
529 continue;
530 for (j = 0; j <= writer_n_durations[i]; j++) {
531 wdp = &wdpp[j];
532 pr_alert("%s%s %4d writer-duration: %5d %llu\n",
533 perf_type, PERF_FLAG,
534 i, j, *wdp);
535 if (j % 100 == 0)
536 schedule_timeout_uninterruptible(1);
537 }
538 kfree(writer_durations[i]);
539 }
540 kfree(writer_tasks);
541 kfree(writer_durations);
542 kfree(writer_n_durations);
543 }
544
545
546 if (cur_ops->cleanup != NULL)
547 cur_ops->cleanup();
548
549 torture_cleanup_end();
550}
551
552
553
554
555
556
557static int compute_real(int n)
558{
559 int nr;
560
561 if (n >= 0) {
562 nr = n;
563 } else {
564 nr = num_online_cpus() + 1 + n;
565 if (nr <= 0)
566 nr = 1;
567 }
568 return nr;
569}
570
571
572
573
574
575static int
576rcu_perf_shutdown(void *arg)
577{
578 do {
579 wait_event(shutdown_wq,
580 atomic_read(&n_rcu_perf_writer_finished) >=
581 nrealwriters);
582 } while (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters);
583 smp_mb();
584 rcu_perf_cleanup();
585 kernel_power_off();
586 return -EINVAL;
587}
588
589
590
591
592
593
594torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu().");
595torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration.");
596torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees.");
597
598static struct task_struct **kfree_reader_tasks;
599static int kfree_nrealthreads;
600static atomic_t n_kfree_perf_thread_started;
601static atomic_t n_kfree_perf_thread_ended;
602
603struct kfree_obj {
604 char kfree_obj[8];
605 struct rcu_head rh;
606};
607
608static int
609kfree_perf_thread(void *arg)
610{
611 int i, loop = 0;
612 long me = (long)arg;
613 struct kfree_obj *alloc_ptr;
614 u64 start_time, end_time;
615 long long mem_begin, mem_during = 0;
616
617 VERBOSE_PERFOUT_STRING("kfree_perf_thread task started");
618 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
619 set_user_nice(current, MAX_NICE);
620
621 start_time = ktime_get_mono_fast_ns();
622
623 if (atomic_inc_return(&n_kfree_perf_thread_started) >= kfree_nrealthreads) {
624 if (gp_exp)
625 b_rcu_gp_test_started = cur_ops->exp_completed() / 2;
626 else
627 b_rcu_gp_test_started = cur_ops->get_gp_seq();
628 }
629
630 do {
631 if (!mem_during) {
632 mem_during = mem_begin = si_mem_available();
633 } else if (loop % (kfree_loops / 4) == 0) {
634 mem_during = (mem_during + si_mem_available()) / 2;
635 }
636
637 for (i = 0; i < kfree_alloc_num; i++) {
638 alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
639 if (!alloc_ptr)
640 return -ENOMEM;
641
642 kfree_rcu(alloc_ptr, rh);
643 }
644
645 cond_resched();
646 } while (!torture_must_stop() && ++loop < kfree_loops);
647
648 if (atomic_inc_return(&n_kfree_perf_thread_ended) >= kfree_nrealthreads) {
649 end_time = ktime_get_mono_fast_ns();
650
651 if (gp_exp)
652 b_rcu_gp_test_finished = cur_ops->exp_completed() / 2;
653 else
654 b_rcu_gp_test_finished = cur_ops->get_gp_seq();
655
656 pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",
657 (unsigned long long)(end_time - start_time), kfree_loops,
658 rcuperf_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
659 (mem_begin - mem_during) >> (20 - PAGE_SHIFT));
660
661 if (shutdown) {
662 smp_mb();
663 wake_up(&shutdown_wq);
664 }
665 }
666
667 torture_kthread_stopping("kfree_perf_thread");
668 return 0;
669}
670
671static void
672kfree_perf_cleanup(void)
673{
674 int i;
675
676 if (torture_cleanup_begin())
677 return;
678
679 if (kfree_reader_tasks) {
680 for (i = 0; i < kfree_nrealthreads; i++)
681 torture_stop_kthread(kfree_perf_thread,
682 kfree_reader_tasks[i]);
683 kfree(kfree_reader_tasks);
684 }
685
686 torture_cleanup_end();
687}
688
689
690
691
692static int
693kfree_perf_shutdown(void *arg)
694{
695 do {
696 wait_event(shutdown_wq,
697 atomic_read(&n_kfree_perf_thread_ended) >=
698 kfree_nrealthreads);
699 } while (atomic_read(&n_kfree_perf_thread_ended) < kfree_nrealthreads);
700
701 smp_mb();
702
703 kfree_perf_cleanup();
704 kernel_power_off();
705 return -EINVAL;
706}
707
708static int __init
709kfree_perf_init(void)
710{
711 long i;
712 int firsterr = 0;
713
714 kfree_nrealthreads = compute_real(kfree_nthreads);
715
716 if (shutdown) {
717 init_waitqueue_head(&shutdown_wq);
718 firsterr = torture_create_kthread(kfree_perf_shutdown, NULL,
719 shutdown_task);
720 if (firsterr)
721 goto unwind;
722 schedule_timeout_uninterruptible(1);
723 }
724
725 kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
726 GFP_KERNEL);
727 if (kfree_reader_tasks == NULL) {
728 firsterr = -ENOMEM;
729 goto unwind;
730 }
731
732 for (i = 0; i < kfree_nrealthreads; i++) {
733 firsterr = torture_create_kthread(kfree_perf_thread, (void *)i,
734 kfree_reader_tasks[i]);
735 if (firsterr)
736 goto unwind;
737 }
738
739 while (atomic_read(&n_kfree_perf_thread_started) < kfree_nrealthreads)
740 schedule_timeout_uninterruptible(1);
741
742 torture_init_end();
743 return 0;
744
745unwind:
746 torture_init_end();
747 kfree_perf_cleanup();
748 return firsterr;
749}
750
751static int __init
752rcu_perf_init(void)
753{
754 long i;
755 int firsterr = 0;
756 static struct rcu_perf_ops *perf_ops[] = {
757 &rcu_ops, &srcu_ops, &srcud_ops, &tasks_ops,
758 };
759
760 if (!torture_init_begin(perf_type, verbose))
761 return -EBUSY;
762
763
764 for (i = 0; i < ARRAY_SIZE(perf_ops); i++) {
765 cur_ops = perf_ops[i];
766 if (strcmp(perf_type, cur_ops->name) == 0)
767 break;
768 }
769 if (i == ARRAY_SIZE(perf_ops)) {
770 pr_alert("rcu-perf: invalid perf type: \"%s\"\n", perf_type);
771 pr_alert("rcu-perf types:");
772 for (i = 0; i < ARRAY_SIZE(perf_ops); i++)
773 pr_cont(" %s", perf_ops[i]->name);
774 pr_cont("\n");
775 WARN_ON(!IS_MODULE(CONFIG_RCU_PERF_TEST));
776 firsterr = -EINVAL;
777 cur_ops = NULL;
778 goto unwind;
779 }
780 if (cur_ops->init)
781 cur_ops->init();
782
783 if (kfree_rcu_test)
784 return kfree_perf_init();
785
786 nrealwriters = compute_real(nwriters);
787 nrealreaders = compute_real(nreaders);
788 atomic_set(&n_rcu_perf_reader_started, 0);
789 atomic_set(&n_rcu_perf_writer_started, 0);
790 atomic_set(&n_rcu_perf_writer_finished, 0);
791 rcu_perf_print_module_parms(cur_ops, "Start of test");
792
793
794
795 if (shutdown) {
796 init_waitqueue_head(&shutdown_wq);
797 firsterr = torture_create_kthread(rcu_perf_shutdown, NULL,
798 shutdown_task);
799 if (firsterr)
800 goto unwind;
801 schedule_timeout_uninterruptible(1);
802 }
803 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
804 GFP_KERNEL);
805 if (reader_tasks == NULL) {
806 VERBOSE_PERFOUT_ERRSTRING("out of memory");
807 firsterr = -ENOMEM;
808 goto unwind;
809 }
810 for (i = 0; i < nrealreaders; i++) {
811 firsterr = torture_create_kthread(rcu_perf_reader, (void *)i,
812 reader_tasks[i]);
813 if (firsterr)
814 goto unwind;
815 }
816 while (atomic_read(&n_rcu_perf_reader_started) < nrealreaders)
817 schedule_timeout_uninterruptible(1);
818 writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
819 GFP_KERNEL);
820 writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
821 GFP_KERNEL);
822 writer_n_durations =
823 kcalloc(nrealwriters, sizeof(*writer_n_durations),
824 GFP_KERNEL);
825 if (!writer_tasks || !writer_durations || !writer_n_durations) {
826 VERBOSE_PERFOUT_ERRSTRING("out of memory");
827 firsterr = -ENOMEM;
828 goto unwind;
829 }
830 for (i = 0; i < nrealwriters; i++) {
831 writer_durations[i] =
832 kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
833 GFP_KERNEL);
834 if (!writer_durations[i]) {
835 firsterr = -ENOMEM;
836 goto unwind;
837 }
838 firsterr = torture_create_kthread(rcu_perf_writer, (void *)i,
839 writer_tasks[i]);
840 if (firsterr)
841 goto unwind;
842 }
843 torture_init_end();
844 return 0;
845
846unwind:
847 torture_init_end();
848 rcu_perf_cleanup();
849 return firsterr;
850}
851
852module_init(rcu_perf_init);
853module_exit(rcu_perf_cleanup);
854