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1/*
2 * Read-Copy Update module-based performance-test facility
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
17 *
18 * Copyright (C) IBM Corporation, 2015
19 *
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 */
22#include <linux/types.h>
23#include <linux/kernel.h>
24#include <linux/init.h>
25#include <linux/module.h>
26#include <linux/kthread.h>
27#include <linux/err.h>
28#include <linux/spinlock.h>
29#include <linux/smp.h>
30#include <linux/rcupdate.h>
31#include <linux/interrupt.h>
32#include <linux/sched.h>
33#include <linux/atomic.h>
34#include <linux/bitops.h>
35#include <linux/completion.h>
36#include <linux/moduleparam.h>
37#include <linux/percpu.h>
38#include <linux/notifier.h>
39#include <linux/reboot.h>
40#include <linux/freezer.h>
41#include <linux/cpu.h>
42#include <linux/delay.h>
43#include <linux/stat.h>
44#include <linux/srcu.h>
45#include <linux/slab.h>
46#include <asm/byteorder.h>
47#include <linux/torture.h>
48#include <linux/vmalloc.h>
49
50MODULE_LICENSE("GPL");
51MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.vnet.ibm.com>");
52
53#define PERF_FLAG "-perf:"
54#define PERFOUT_STRING(s) \
55 pr_alert("%s" PERF_FLAG " %s\n", perf_type, s)
56#define VERBOSE_PERFOUT_STRING(s) \
57 do { if (verbose) pr_alert("%s" PERF_FLAG " %s\n", perf_type, s); } while (0)
58#define VERBOSE_PERFOUT_ERRSTRING(s) \
59 do { if (verbose) pr_alert("%s" PERF_FLAG "!!! %s\n", perf_type, s); } while (0)
60
61torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
62torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
63torture_param(int, nreaders, -1, "Number of RCU reader threads");
64torture_param(int, nwriters, -1, "Number of RCU updater threads");
65torture_param(bool, shutdown, false, "Shutdown at end of performance tests.");
66torture_param(bool, verbose, true, "Enable verbose debugging printk()s");
67
68static char *perf_type = "rcu";
69module_param(perf_type, charp, 0444);
70MODULE_PARM_DESC(perf_type, "Type of RCU to performance-test (rcu, rcu_bh, ...)");
71
72static int nrealreaders;
73static int nrealwriters;
74static struct task_struct **writer_tasks;
75static struct task_struct **reader_tasks;
76static struct task_struct *shutdown_task;
77
78static u64 **writer_durations;
79static int *writer_n_durations;
80static atomic_t n_rcu_perf_reader_started;
81static atomic_t n_rcu_perf_writer_started;
82static atomic_t n_rcu_perf_writer_finished;
83static wait_queue_head_t shutdown_wq;
84static u64 t_rcu_perf_writer_started;
85static u64 t_rcu_perf_writer_finished;
86static unsigned long b_rcu_perf_writer_started;
87static unsigned long b_rcu_perf_writer_finished;
88
89static int rcu_perf_writer_state;
90#define RTWS_INIT 0
91#define RTWS_EXP_SYNC 1
92#define RTWS_SYNC 2
93#define RTWS_IDLE 2
94#define RTWS_STOPPING 3
95
96#define MAX_MEAS 10000
97#define MIN_MEAS 100
98
99static int perf_runnable = IS_ENABLED(MODULE);
100module_param(perf_runnable, int, 0444);
101MODULE_PARM_DESC(perf_runnable, "Start rcuperf at boot");
102
103/*
104 * Operations vector for selecting different types of tests.
105 */
106
107struct rcu_perf_ops {
108 int ptype;
109 void (*init)(void);
110 void (*cleanup)(void);
111 int (*readlock)(void);
112 void (*readunlock)(int idx);
113 unsigned long (*started)(void);
114 unsigned long (*completed)(void);
115 unsigned long (*exp_completed)(void);
116 void (*sync)(void);
117 void (*exp_sync)(void);
118 const char *name;
119};
120
121static struct rcu_perf_ops *cur_ops;
122
123/*
124 * Definitions for rcu perf testing.
125 */
126
127static int rcu_perf_read_lock(void) __acquires(RCU)
128{
129 rcu_read_lock();
130 return 0;
131}
132
133static void rcu_perf_read_unlock(int idx) __releases(RCU)
134{
135 rcu_read_unlock();
136}
137
138static unsigned long __maybe_unused rcu_no_completed(void)
139{
140 return 0;
141}
142
143static void rcu_sync_perf_init(void)
144{
145}
146
147static struct rcu_perf_ops rcu_ops = {
148 .ptype = RCU_FLAVOR,
149 .init = rcu_sync_perf_init,
150 .readlock = rcu_perf_read_lock,
151 .readunlock = rcu_perf_read_unlock,
152 .started = rcu_batches_started,
153 .completed = rcu_batches_completed,
154 .exp_completed = rcu_exp_batches_completed,
155 .sync = synchronize_rcu,
156 .exp_sync = synchronize_rcu_expedited,
157 .name = "rcu"
158};
159
160/*
161 * Definitions for rcu_bh perf testing.
162 */
163
164static int rcu_bh_perf_read_lock(void) __acquires(RCU_BH)
165{
166 rcu_read_lock_bh();
167 return 0;
168}
169
170static void rcu_bh_perf_read_unlock(int idx) __releases(RCU_BH)
171{
172 rcu_read_unlock_bh();
173}
174
175static struct rcu_perf_ops rcu_bh_ops = {
176 .ptype = RCU_BH_FLAVOR,
177 .init = rcu_sync_perf_init,
178 .readlock = rcu_bh_perf_read_lock,
179 .readunlock = rcu_bh_perf_read_unlock,
180 .started = rcu_batches_started_bh,
181 .completed = rcu_batches_completed_bh,
182 .exp_completed = rcu_exp_batches_completed_sched,
183 .sync = synchronize_rcu_bh,
184 .exp_sync = synchronize_rcu_bh_expedited,
185 .name = "rcu_bh"
186};
187
188/*
189 * Definitions for srcu perf testing.
190 */
191
192DEFINE_STATIC_SRCU(srcu_ctl_perf);
193static struct srcu_struct *srcu_ctlp = &srcu_ctl_perf;
194
195static int srcu_perf_read_lock(void) __acquires(srcu_ctlp)
196{
197 return srcu_read_lock(srcu_ctlp);
198}
199
200static void srcu_perf_read_unlock(int idx) __releases(srcu_ctlp)
201{
202 srcu_read_unlock(srcu_ctlp, idx);
203}
204
205static unsigned long srcu_perf_completed(void)
206{
207 return srcu_batches_completed(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 .started = NULL,
226 .completed = srcu_perf_completed,
227 .exp_completed = srcu_perf_completed,
228 .sync = srcu_perf_synchronize,
229 .exp_sync = srcu_perf_synchronize_expedited,
230 .name = "srcu"
231};
232
233/*
234 * Definitions for sched perf testing.
235 */
236
237static int sched_perf_read_lock(void)
238{
239 preempt_disable();
240 return 0;
241}
242
243static void sched_perf_read_unlock(int idx)
244{
245 preempt_enable();
246}
247
248static struct rcu_perf_ops sched_ops = {
249 .ptype = RCU_SCHED_FLAVOR,
250 .init = rcu_sync_perf_init,
251 .readlock = sched_perf_read_lock,
252 .readunlock = sched_perf_read_unlock,
253 .started = rcu_batches_started_sched,
254 .completed = rcu_batches_completed_sched,
255 .exp_completed = rcu_exp_batches_completed_sched,
256 .sync = synchronize_sched,
257 .exp_sync = synchronize_sched_expedited,
258 .name = "sched"
259};
260
261#ifdef CONFIG_TASKS_RCU
262
263/*
264 * Definitions for RCU-tasks perf testing.
265 */
266
267static int tasks_perf_read_lock(void)
268{
269 return 0;
270}
271
272static void tasks_perf_read_unlock(int idx)
273{
274}
275
276static struct rcu_perf_ops tasks_ops = {
277 .ptype = RCU_TASKS_FLAVOR,
278 .init = rcu_sync_perf_init,
279 .readlock = tasks_perf_read_lock,
280 .readunlock = tasks_perf_read_unlock,
281 .started = rcu_no_completed,
282 .completed = rcu_no_completed,
283 .sync = synchronize_rcu_tasks,
284 .exp_sync = synchronize_rcu_tasks,
285 .name = "tasks"
286};
287
288#define RCUPERF_TASKS_OPS &tasks_ops,
289
290static bool __maybe_unused torturing_tasks(void)
291{
292 return cur_ops == &tasks_ops;
293}
294
295#else /* #ifdef CONFIG_TASKS_RCU */
296
297#define RCUPERF_TASKS_OPS
298
299static bool __maybe_unused torturing_tasks(void)
300{
301 return false;
302}
303
304#endif /* #else #ifdef CONFIG_TASKS_RCU */
305
306/*
307 * If performance tests complete, wait for shutdown to commence.
308 */
309static void rcu_perf_wait_shutdown(void)
310{
311 cond_resched_rcu_qs();
312 if (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters)
313 return;
314 while (!torture_must_stop())
315 schedule_timeout_uninterruptible(1);
316}
317
318/*
319 * RCU perf reader kthread. Repeatedly does empty RCU read-side
320 * critical section, minimizing update-side interference.
321 */
322static int
323rcu_perf_reader(void *arg)
324{
325 unsigned long flags;
326 int idx;
327 long me = (long)arg;
328
329 VERBOSE_PERFOUT_STRING("rcu_perf_reader task started");
330 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
331 set_user_nice(current, MAX_NICE);
332 atomic_inc(&n_rcu_perf_reader_started);
333
334 do {
335 local_irq_save(flags);
336 idx = cur_ops->readlock();
337 cur_ops->readunlock(idx);
338 local_irq_restore(flags);
339 rcu_perf_wait_shutdown();
340 } while (!torture_must_stop());
341 torture_kthread_stopping("rcu_perf_reader");
342 return 0;
343}
344
345/*
346 * RCU perf writer kthread. Repeatedly does a grace period.
347 */
348static int
349rcu_perf_writer(void *arg)
350{
351 int i = 0;
352 int i_max;
353 long me = (long)arg;
354 struct sched_param sp;
355 bool started = false, done = false, alldone = false;
356 u64 t;
357 u64 *wdp;
358 u64 *wdpp = writer_durations[me];
359
360 VERBOSE_PERFOUT_STRING("rcu_perf_writer task started");
361 WARN_ON(!wdpp);
362 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
363 sp.sched_priority = 1;
364 sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
365
366 if (holdoff)
367 schedule_timeout_uninterruptible(holdoff * HZ);
368
369 t = ktime_get_mono_fast_ns();
370 if (atomic_inc_return(&n_rcu_perf_writer_started) >= nrealwriters) {
371 t_rcu_perf_writer_started = t;
372 if (gp_exp) {
373 b_rcu_perf_writer_started =
374 cur_ops->exp_completed() / 2;
375 } else {
376 b_rcu_perf_writer_started =
377 cur_ops->completed();
378 }
379 }
380
381 do {
382 wdp = &wdpp[i];
383 *wdp = ktime_get_mono_fast_ns();
384 if (gp_exp) {
385 rcu_perf_writer_state = RTWS_EXP_SYNC;
386 cur_ops->exp_sync();
387 } else {
388 rcu_perf_writer_state = RTWS_SYNC;
389 cur_ops->sync();
390 }
391 rcu_perf_writer_state = RTWS_IDLE;
392 t = ktime_get_mono_fast_ns();
393 *wdp = t - *wdp;
394 i_max = i;
395 if (!started &&
396 atomic_read(&n_rcu_perf_writer_started) >= nrealwriters)
397 started = true;
398 if (!done && i >= MIN_MEAS) {
399 done = true;
400 sp.sched_priority = 0;
401 sched_setscheduler_nocheck(current,
402 SCHED_NORMAL, &sp);
403 pr_alert("%s%s rcu_perf_writer %ld has %d measurements\n",
404 perf_type, PERF_FLAG, me, MIN_MEAS);
405 if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
406 nrealwriters) {
407 schedule_timeout_interruptible(10);
408 rcu_ftrace_dump(DUMP_ALL);
409 PERFOUT_STRING("Test complete");
410 t_rcu_perf_writer_finished = t;
411 if (gp_exp) {
412 b_rcu_perf_writer_finished =
413 cur_ops->exp_completed() / 2;
414 } else {
415 b_rcu_perf_writer_finished =
416 cur_ops->completed();
417 }
418 if (shutdown) {
419 smp_mb(); /* Assign before wake. */
420 wake_up(&shutdown_wq);
421 }
422 }
423 }
424 if (done && !alldone &&
425 atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)
426 alldone = true;
427 if (started && !alldone && i < MAX_MEAS - 1)
428 i++;
429 rcu_perf_wait_shutdown();
430 } while (!torture_must_stop());
431 rcu_perf_writer_state = RTWS_STOPPING;
432 writer_n_durations[me] = i_max;
433 torture_kthread_stopping("rcu_perf_writer");
434 return 0;
435}
436
437static inline void
438rcu_perf_print_module_parms(struct rcu_perf_ops *cur_ops, const char *tag)
439{
440 pr_alert("%s" PERF_FLAG
441 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
442 perf_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
443}
444
445static void
446rcu_perf_cleanup(void)
447{
448 int i;
449 int j;
450 int ngps = 0;
451 u64 *wdp;
452 u64 *wdpp;
453
454 if (torture_cleanup_begin())
455 return;
456
457 if (reader_tasks) {
458 for (i = 0; i < nrealreaders; i++)
459 torture_stop_kthread(rcu_perf_reader,
460 reader_tasks[i]);
461 kfree(reader_tasks);
462 }
463
464 if (writer_tasks) {
465 for (i = 0; i < nrealwriters; i++) {
466 torture_stop_kthread(rcu_perf_writer,
467 writer_tasks[i]);
468 if (!writer_n_durations)
469 continue;
470 j = writer_n_durations[i];
471 pr_alert("%s%s writer %d gps: %d\n",
472 perf_type, PERF_FLAG, i, j);
473 ngps += j;
474 }
475 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
476 perf_type, PERF_FLAG,
477 t_rcu_perf_writer_started, t_rcu_perf_writer_finished,
478 t_rcu_perf_writer_finished -
479 t_rcu_perf_writer_started,
480 ngps,
481 b_rcu_perf_writer_finished -
482 b_rcu_perf_writer_started);
483 for (i = 0; i < nrealwriters; i++) {
484 if (!writer_durations)
485 break;
486 if (!writer_n_durations)
487 continue;
488 wdpp = writer_durations[i];
489 if (!wdpp)
490 continue;
491 for (j = 0; j <= writer_n_durations[i]; j++) {
492 wdp = &wdpp[j];
493 pr_alert("%s%s %4d writer-duration: %5d %llu\n",
494 perf_type, PERF_FLAG,
495 i, j, *wdp);
496 if (j % 100 == 0)
497 schedule_timeout_uninterruptible(1);
498 }
499 kfree(writer_durations[i]);
500 }
501 kfree(writer_tasks);
502 kfree(writer_durations);
503 kfree(writer_n_durations);
504 }
505
506 /* Do flavor-specific cleanup operations. */
507 if (cur_ops->cleanup != NULL)
508 cur_ops->cleanup();
509
510 torture_cleanup_end();
511}
512
513/*
514 * Return the number if non-negative. If -1, the number of CPUs.
515 * If less than -1, that much less than the number of CPUs, but
516 * at least one.
517 */
518static int compute_real(int n)
519{
520 int nr;
521
522 if (n >= 0) {
523 nr = n;
524 } else {
525 nr = num_online_cpus() + 1 + n;
526 if (nr <= 0)
527 nr = 1;
528 }
529 return nr;
530}
531
532/*
533 * RCU perf shutdown kthread. Just waits to be awakened, then shuts
534 * down system.
535 */
536static int
537rcu_perf_shutdown(void *arg)
538{
539 do {
540 wait_event(shutdown_wq,
541 atomic_read(&n_rcu_perf_writer_finished) >=
542 nrealwriters);
543 } while (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters);
544 smp_mb(); /* Wake before output. */
545 rcu_perf_cleanup();
546 kernel_power_off();
547 return -EINVAL;
548}
549
550static int __init
551rcu_perf_init(void)
552{
553 long i;
554 int firsterr = 0;
555 static struct rcu_perf_ops *perf_ops[] = {
556 &rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops,
557 RCUPERF_TASKS_OPS
558 };
559
560 if (!torture_init_begin(perf_type, verbose, &perf_runnable))
561 return -EBUSY;
562
563 /* Process args and tell the world that the perf'er is on the job. */
564 for (i = 0; i < ARRAY_SIZE(perf_ops); i++) {
565 cur_ops = perf_ops[i];
566 if (strcmp(perf_type, cur_ops->name) == 0)
567 break;
568 }
569 if (i == ARRAY_SIZE(perf_ops)) {
570 pr_alert("rcu-perf: invalid perf type: \"%s\"\n",
571 perf_type);
572 pr_alert("rcu-perf types:");
573 for (i = 0; i < ARRAY_SIZE(perf_ops); i++)
574 pr_alert(" %s", perf_ops[i]->name);
575 pr_alert("\n");
576 firsterr = -EINVAL;
577 goto unwind;
578 }
579 if (cur_ops->init)
580 cur_ops->init();
581
582 nrealwriters = compute_real(nwriters);
583 nrealreaders = compute_real(nreaders);
584 atomic_set(&n_rcu_perf_reader_started, 0);
585 atomic_set(&n_rcu_perf_writer_started, 0);
586 atomic_set(&n_rcu_perf_writer_finished, 0);
587 rcu_perf_print_module_parms(cur_ops, "Start of test");
588
589 /* Start up the kthreads. */
590
591 if (shutdown) {
592 init_waitqueue_head(&shutdown_wq);
593 firsterr = torture_create_kthread(rcu_perf_shutdown, NULL,
594 shutdown_task);
595 if (firsterr)
596 goto unwind;
597 schedule_timeout_uninterruptible(1);
598 }
599 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
600 GFP_KERNEL);
601 if (reader_tasks == NULL) {
602 VERBOSE_PERFOUT_ERRSTRING("out of memory");
603 firsterr = -ENOMEM;
604 goto unwind;
605 }
606 for (i = 0; i < nrealreaders; i++) {
607 firsterr = torture_create_kthread(rcu_perf_reader, (void *)i,
608 reader_tasks[i]);
609 if (firsterr)
610 goto unwind;
611 }
612 while (atomic_read(&n_rcu_perf_reader_started) < nrealreaders)
613 schedule_timeout_uninterruptible(1);
614 writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
615 GFP_KERNEL);
616 writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
617 GFP_KERNEL);
618 writer_n_durations =
619 kcalloc(nrealwriters, sizeof(*writer_n_durations),
620 GFP_KERNEL);
621 if (!writer_tasks || !writer_durations || !writer_n_durations) {
622 VERBOSE_PERFOUT_ERRSTRING("out of memory");
623 firsterr = -ENOMEM;
624 goto unwind;
625 }
626 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp) {
627 VERBOSE_PERFOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
628 firsterr = -EINVAL;
629 goto unwind;
630 }
631 if (rcu_gp_is_normal() && gp_exp) {
632 VERBOSE_PERFOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
633 firsterr = -EINVAL;
634 goto unwind;
635 }
636 for (i = 0; i < nrealwriters; i++) {
637 writer_durations[i] =
638 kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
639 GFP_KERNEL);
640 if (!writer_durations[i]) {
641 firsterr = -ENOMEM;
642 goto unwind;
643 }
644 firsterr = torture_create_kthread(rcu_perf_writer, (void *)i,
645 writer_tasks[i]);
646 if (firsterr)
647 goto unwind;
648 }
649 torture_init_end();
650 return 0;
651
652unwind:
653 torture_init_end();
654 rcu_perf_cleanup();
655 return firsterr;
656}
657
658module_init(rcu_perf_init);
659module_exit(rcu_perf_cleanup);
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Read-Copy Update module-based performance-test facility
4 *
5 * Copyright (C) IBM Corporation, 2015
6 *
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
8 */
9
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)
54
55/*
56 * The intended use cases for the nreaders and nwriters module parameters
57 * are as follows:
58 *
59 * 1. Specify only the nr_cpus kernel boot parameter. This will
60 * set both nreaders and nwriters to the value specified by
61 * nr_cpus for a mixed reader/writer test.
62 *
63 * 2. Specify the nr_cpus kernel boot parameter, but set
64 * rcuperf.nreaders to zero. This will set nwriters to the
65 * value specified by nr_cpus for an update-only test.
66 *
67 * 3. Specify the nr_cpus kernel boot parameter, but set
68 * rcuperf.nwriters to zero. This will set nreaders to the
69 * value specified by nr_cpus for a read-only test.
70 *
71 * Various other use cases may of course be specified.
72 *
73 * Note that this test's readers are intended only as a test load for
74 * the writers. The reader performance statistics will be overly
75 * pessimistic due to the per-critical-section interrupt disabling,
76 * test-end checks, and the pair of calls through pointers.
77 */
78
79#ifdef MODULE
80# define RCUPERF_SHUTDOWN 0
81#else
82# define RCUPERF_SHUTDOWN 1
83#endif
84
85torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
86torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
87torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
88torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
89torture_param(int, nreaders, -1, "Number of RCU reader threads");
90torture_param(int, nwriters, -1, "Number of RCU updater threads");
91torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
92 "Shutdown at end of performance tests.");
93torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
94torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
95torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
96torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
97
98static char *perf_type = "rcu";
99module_param(perf_type, charp, 0444);
100MODULE_PARM_DESC(perf_type, "Type of RCU to performance-test (rcu, srcu, ...)");
101
102static int nrealreaders;
103static int nrealwriters;
104static struct task_struct **writer_tasks;
105static struct task_struct **reader_tasks;
106static struct task_struct *shutdown_task;
107
108static u64 **writer_durations;
109static int *writer_n_durations;
110static atomic_t n_rcu_perf_reader_started;
111static atomic_t n_rcu_perf_writer_started;
112static atomic_t n_rcu_perf_writer_finished;
113static wait_queue_head_t shutdown_wq;
114static u64 t_rcu_perf_writer_started;
115static u64 t_rcu_perf_writer_finished;
116static unsigned long b_rcu_gp_test_started;
117static unsigned long b_rcu_gp_test_finished;
118static DEFINE_PER_CPU(atomic_t, n_async_inflight);
119
120#define MAX_MEAS 10000
121#define MIN_MEAS 100
122
123/*
124 * Operations vector for selecting different types of tests.
125 */
126
127struct rcu_perf_ops {
128 int ptype;
129 void (*init)(void);
130 void (*cleanup)(void);
131 int (*readlock)(void);
132 void (*readunlock)(int idx);
133 unsigned long (*get_gp_seq)(void);
134 unsigned long (*gp_diff)(unsigned long new, unsigned long old);
135 unsigned long (*exp_completed)(void);
136 void (*async)(struct rcu_head *head, rcu_callback_t func);
137 void (*gp_barrier)(void);
138 void (*sync)(void);
139 void (*exp_sync)(void);
140 const char *name;
141};
142
143static struct rcu_perf_ops *cur_ops;
144
145/*
146 * Definitions for rcu perf testing.
147 */
148
149static int rcu_perf_read_lock(void) __acquires(RCU)
150{
151 rcu_read_lock();
152 return 0;
153}
154
155static void rcu_perf_read_unlock(int idx) __releases(RCU)
156{
157 rcu_read_unlock();
158}
159
160static unsigned long __maybe_unused rcu_no_completed(void)
161{
162 return 0;
163}
164
165static void rcu_sync_perf_init(void)
166{
167}
168
169static struct rcu_perf_ops rcu_ops = {
170 .ptype = RCU_FLAVOR,
171 .init = rcu_sync_perf_init,
172 .readlock = rcu_perf_read_lock,
173 .readunlock = rcu_perf_read_unlock,
174 .get_gp_seq = rcu_get_gp_seq,
175 .gp_diff = rcu_seq_diff,
176 .exp_completed = rcu_exp_batches_completed,
177 .async = call_rcu,
178 .gp_barrier = rcu_barrier,
179 .sync = synchronize_rcu,
180 .exp_sync = synchronize_rcu_expedited,
181 .name = "rcu"
182};
183
184/*
185 * Definitions for srcu perf testing.
186 */
187
188DEFINE_STATIC_SRCU(srcu_ctl_perf);
189static struct srcu_struct *srcu_ctlp = &srcu_ctl_perf;
190
191static int srcu_perf_read_lock(void) __acquires(srcu_ctlp)
192{
193 return srcu_read_lock(srcu_ctlp);
194}
195
196static void srcu_perf_read_unlock(int idx) __releases(srcu_ctlp)
197{
198 srcu_read_unlock(srcu_ctlp, idx);
199}
200
201static unsigned long srcu_perf_completed(void)
202{
203 return srcu_batches_completed(srcu_ctlp);
204}
205
206static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
207{
208 call_srcu(srcu_ctlp, head, func);
209}
210
211static void srcu_rcu_barrier(void)
212{
213 srcu_barrier(srcu_ctlp);
214}
215
216static void srcu_perf_synchronize(void)
217{
218 synchronize_srcu(srcu_ctlp);
219}
220
221static void srcu_perf_synchronize_expedited(void)
222{
223 synchronize_srcu_expedited(srcu_ctlp);
224}
225
226static struct rcu_perf_ops srcu_ops = {
227 .ptype = SRCU_FLAVOR,
228 .init = rcu_sync_perf_init,
229 .readlock = srcu_perf_read_lock,
230 .readunlock = srcu_perf_read_unlock,
231 .get_gp_seq = srcu_perf_completed,
232 .gp_diff = rcu_seq_diff,
233 .exp_completed = srcu_perf_completed,
234 .async = srcu_call_rcu,
235 .gp_barrier = srcu_rcu_barrier,
236 .sync = srcu_perf_synchronize,
237 .exp_sync = srcu_perf_synchronize_expedited,
238 .name = "srcu"
239};
240
241static struct srcu_struct srcud;
242
243static void srcu_sync_perf_init(void)
244{
245 srcu_ctlp = &srcud;
246 init_srcu_struct(srcu_ctlp);
247}
248
249static void srcu_sync_perf_cleanup(void)
250{
251 cleanup_srcu_struct(srcu_ctlp);
252}
253
254static struct rcu_perf_ops srcud_ops = {
255 .ptype = SRCU_FLAVOR,
256 .init = srcu_sync_perf_init,
257 .cleanup = srcu_sync_perf_cleanup,
258 .readlock = srcu_perf_read_lock,
259 .readunlock = srcu_perf_read_unlock,
260 .get_gp_seq = srcu_perf_completed,
261 .gp_diff = rcu_seq_diff,
262 .exp_completed = srcu_perf_completed,
263 .async = srcu_call_rcu,
264 .gp_barrier = srcu_rcu_barrier,
265 .sync = srcu_perf_synchronize,
266 .exp_sync = srcu_perf_synchronize_expedited,
267 .name = "srcud"
268};
269
270/*
271 * Definitions for RCU-tasks perf testing.
272 */
273
274static int tasks_perf_read_lock(void)
275{
276 return 0;
277}
278
279static void tasks_perf_read_unlock(int idx)
280{
281}
282
283static struct rcu_perf_ops tasks_ops = {
284 .ptype = RCU_TASKS_FLAVOR,
285 .init = rcu_sync_perf_init,
286 .readlock = tasks_perf_read_lock,
287 .readunlock = tasks_perf_read_unlock,
288 .get_gp_seq = rcu_no_completed,
289 .gp_diff = rcu_seq_diff,
290 .async = call_rcu_tasks,
291 .gp_barrier = rcu_barrier_tasks,
292 .sync = synchronize_rcu_tasks,
293 .exp_sync = synchronize_rcu_tasks,
294 .name = "tasks"
295};
296
297static unsigned long rcuperf_seq_diff(unsigned long new, unsigned long old)
298{
299 if (!cur_ops->gp_diff)
300 return new - old;
301 return cur_ops->gp_diff(new, old);
302}
303
304/*
305 * If performance tests complete, wait for shutdown to commence.
306 */
307static void rcu_perf_wait_shutdown(void)
308{
309 cond_resched_tasks_rcu_qs();
310 if (atomic_read(&n_rcu_perf_writer_finished) < nrealwriters)
311 return;
312 while (!torture_must_stop())
313 schedule_timeout_uninterruptible(1);
314}
315
316/*
317 * RCU perf reader kthread. Repeatedly does empty RCU read-side critical
318 * section, minimizing update-side interference. However, the point of
319 * this test is not to evaluate reader performance, but instead to serve
320 * as a test load for update-side performance testing.
321 */
322static int
323rcu_perf_reader(void *arg)
324{
325 unsigned long flags;
326 int idx;
327 long me = (long)arg;
328
329 VERBOSE_PERFOUT_STRING("rcu_perf_reader task started");
330 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
331 set_user_nice(current, MAX_NICE);
332 atomic_inc(&n_rcu_perf_reader_started);
333
334 do {
335 local_irq_save(flags);
336 idx = cur_ops->readlock();
337 cur_ops->readunlock(idx);
338 local_irq_restore(flags);
339 rcu_perf_wait_shutdown();
340 } while (!torture_must_stop());
341 torture_kthread_stopping("rcu_perf_reader");
342 return 0;
343}
344
345/*
346 * Callback function for asynchronous grace periods from rcu_perf_writer().
347 */
348static void rcu_perf_async_cb(struct rcu_head *rhp)
349{
350 atomic_dec(this_cpu_ptr(&n_async_inflight));
351 kfree(rhp);
352}
353
354/*
355 * RCU perf writer kthread. Repeatedly does a grace period.
356 */
357static int
358rcu_perf_writer(void *arg)
359{
360 int i = 0;
361 int i_max;
362 long me = (long)arg;
363 struct rcu_head *rhp = NULL;
364 bool started = false, done = false, alldone = false;
365 u64 t;
366 u64 *wdp;
367 u64 *wdpp = writer_durations[me];
368
369 VERBOSE_PERFOUT_STRING("rcu_perf_writer task started");
370 WARN_ON(!wdpp);
371 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
372 sched_set_fifo_low(current);
373
374 if (holdoff)
375 schedule_timeout_uninterruptible(holdoff * HZ);
376
377 /*
378 * Wait until rcu_end_inkernel_boot() is called for normal GP tests
379 * so that RCU is not always expedited for normal GP tests.
380 * The system_state test is approximate, but works well in practice.
381 */
382 while (!gp_exp && system_state != SYSTEM_RUNNING)
383 schedule_timeout_uninterruptible(1);
384
385 t = ktime_get_mono_fast_ns();
386 if (atomic_inc_return(&n_rcu_perf_writer_started) >= nrealwriters) {
387 t_rcu_perf_writer_started = t;
388 if (gp_exp) {
389 b_rcu_gp_test_started =
390 cur_ops->exp_completed() / 2;
391 } else {
392 b_rcu_gp_test_started = cur_ops->get_gp_seq();
393 }
394 }
395
396 do {
397 if (writer_holdoff)
398 udelay(writer_holdoff);
399 wdp = &wdpp[i];
400 *wdp = ktime_get_mono_fast_ns();
401 if (gp_async) {
402retry:
403 if (!rhp)
404 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
405 if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
406 atomic_inc(this_cpu_ptr(&n_async_inflight));
407 cur_ops->async(rhp, rcu_perf_async_cb);
408 rhp = NULL;
409 } else if (!kthread_should_stop()) {
410 cur_ops->gp_barrier();
411 goto retry;
412 } else {
413 kfree(rhp); /* Because we are stopping. */
414 }
415 } else if (gp_exp) {
416 cur_ops->exp_sync();
417 } else {
418 cur_ops->sync();
419 }
420 t = ktime_get_mono_fast_ns();
421 *wdp = t - *wdp;
422 i_max = i;
423 if (!started &&
424 atomic_read(&n_rcu_perf_writer_started) >= nrealwriters)
425 started = true;
426 if (!done && i >= MIN_MEAS) {
427 done = true;
428 sched_set_normal(current, 0);
429 pr_alert("%s%s rcu_perf_writer %ld has %d measurements\n",
430 perf_type, PERF_FLAG, me, MIN_MEAS);
431 if (atomic_inc_return(&n_rcu_perf_writer_finished) >=
432 nrealwriters) {
433 schedule_timeout_interruptible(10);
434 rcu_ftrace_dump(DUMP_ALL);
435 PERFOUT_STRING("Test complete");
436 t_rcu_perf_writer_finished = t;
437 if (gp_exp) {
438 b_rcu_gp_test_finished =
439 cur_ops->exp_completed() / 2;
440 } else {
441 b_rcu_gp_test_finished =
442 cur_ops->get_gp_seq();
443 }
444 if (shutdown) {
445 smp_mb(); /* Assign before wake. */
446 wake_up(&shutdown_wq);
447 }
448 }
449 }
450 if (done && !alldone &&
451 atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters)
452 alldone = true;
453 if (started && !alldone && i < MAX_MEAS - 1)
454 i++;
455 rcu_perf_wait_shutdown();
456 } while (!torture_must_stop());
457 if (gp_async) {
458 cur_ops->gp_barrier();
459 }
460 writer_n_durations[me] = i_max;
461 torture_kthread_stopping("rcu_perf_writer");
462 return 0;
463}
464
465static void
466rcu_perf_print_module_parms(struct rcu_perf_ops *cur_ops, const char *tag)
467{
468 pr_alert("%s" PERF_FLAG
469 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
470 perf_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
471}
472
473static void
474rcu_perf_cleanup(void)
475{
476 int i;
477 int j;
478 int ngps = 0;
479 u64 *wdp;
480 u64 *wdpp;
481
482 /*
483 * Would like warning at start, but everything is expedited
484 * during the mid-boot phase, so have to wait till the end.
485 */
486 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
487 VERBOSE_PERFOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
488 if (rcu_gp_is_normal() && gp_exp)
489 VERBOSE_PERFOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
490 if (gp_exp && gp_async)
491 VERBOSE_PERFOUT_ERRSTRING("No expedited async GPs, so went with async!");
492
493 if (torture_cleanup_begin())
494 return;
495 if (!cur_ops) {
496 torture_cleanup_end();
497 return;
498 }
499
500 if (reader_tasks) {
501 for (i = 0; i < nrealreaders; i++)
502 torture_stop_kthread(rcu_perf_reader,
503 reader_tasks[i]);
504 kfree(reader_tasks);
505 }
506
507 if (writer_tasks) {
508 for (i = 0; i < nrealwriters; i++) {
509 torture_stop_kthread(rcu_perf_writer,
510 writer_tasks[i]);
511 if (!writer_n_durations)
512 continue;
513 j = writer_n_durations[i];
514 pr_alert("%s%s writer %d gps: %d\n",
515 perf_type, PERF_FLAG, i, j);
516 ngps += j;
517 }
518 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
519 perf_type, PERF_FLAG,
520 t_rcu_perf_writer_started, t_rcu_perf_writer_finished,
521 t_rcu_perf_writer_finished -
522 t_rcu_perf_writer_started,
523 ngps,
524 rcuperf_seq_diff(b_rcu_gp_test_finished,
525 b_rcu_gp_test_started));
526 for (i = 0; i < nrealwriters; i++) {
527 if (!writer_durations)
528 break;
529 if (!writer_n_durations)
530 continue;
531 wdpp = writer_durations[i];
532 if (!wdpp)
533 continue;
534 for (j = 0; j <= writer_n_durations[i]; j++) {
535 wdp = &wdpp[j];
536 pr_alert("%s%s %4d writer-duration: %5d %llu\n",
537 perf_type, PERF_FLAG,
538 i, j, *wdp);
539 if (j % 100 == 0)
540 schedule_timeout_uninterruptible(1);
541 }
542 kfree(writer_durations[i]);
543 }
544 kfree(writer_tasks);
545 kfree(writer_durations);
546 kfree(writer_n_durations);
547 }
548
549 /* Do torture-type-specific cleanup operations. */
550 if (cur_ops->cleanup != NULL)
551 cur_ops->cleanup();
552
553 torture_cleanup_end();
554}
555
556/*
557 * Return the number if non-negative. If -1, the number of CPUs.
558 * If less than -1, that much less than the number of CPUs, but
559 * at least one.
560 */
561static int compute_real(int n)
562{
563 int nr;
564
565 if (n >= 0) {
566 nr = n;
567 } else {
568 nr = num_online_cpus() + 1 + n;
569 if (nr <= 0)
570 nr = 1;
571 }
572 return nr;
573}
574
575/*
576 * RCU perf shutdown kthread. Just waits to be awakened, then shuts
577 * down system.
578 */
579static int
580rcu_perf_shutdown(void *arg)
581{
582 wait_event(shutdown_wq,
583 atomic_read(&n_rcu_perf_writer_finished) >= nrealwriters);
584 smp_mb(); /* Wake before output. */
585 rcu_perf_cleanup();
586 kernel_power_off();
587 return -EINVAL;
588}
589
590/*
591 * kfree_rcu() performance tests: Start a kfree_rcu() loop on all CPUs for number
592 * of iterations and measure total time and number of GP for all iterations to complete.
593 */
594
595torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu().");
596torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration.");
597torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees.");
598
599static struct task_struct **kfree_reader_tasks;
600static int kfree_nrealthreads;
601static atomic_t n_kfree_perf_thread_started;
602static atomic_t n_kfree_perf_thread_ended;
603
604struct kfree_obj {
605 char kfree_obj[8];
606 struct rcu_head rh;
607};
608
609static int
610kfree_perf_thread(void *arg)
611{
612 int i, loop = 0;
613 long me = (long)arg;
614 struct kfree_obj *alloc_ptr;
615 u64 start_time, end_time;
616 long long mem_begin, mem_during = 0;
617
618 VERBOSE_PERFOUT_STRING("kfree_perf_thread task started");
619 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
620 set_user_nice(current, MAX_NICE);
621
622 start_time = ktime_get_mono_fast_ns();
623
624 if (atomic_inc_return(&n_kfree_perf_thread_started) >= kfree_nrealthreads) {
625 if (gp_exp)
626 b_rcu_gp_test_started = cur_ops->exp_completed() / 2;
627 else
628 b_rcu_gp_test_started = cur_ops->get_gp_seq();
629 }
630
631 do {
632 if (!mem_during) {
633 mem_during = mem_begin = si_mem_available();
634 } else if (loop % (kfree_loops / 4) == 0) {
635 mem_during = (mem_during + si_mem_available()) / 2;
636 }
637
638 for (i = 0; i < kfree_alloc_num; i++) {
639 alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
640 if (!alloc_ptr)
641 return -ENOMEM;
642
643 kfree_rcu(alloc_ptr, rh);
644 }
645
646 cond_resched();
647 } while (!torture_must_stop() && ++loop < kfree_loops);
648
649 if (atomic_inc_return(&n_kfree_perf_thread_ended) >= kfree_nrealthreads) {
650 end_time = ktime_get_mono_fast_ns();
651
652 if (gp_exp)
653 b_rcu_gp_test_finished = cur_ops->exp_completed() / 2;
654 else
655 b_rcu_gp_test_finished = cur_ops->get_gp_seq();
656
657 pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",
658 (unsigned long long)(end_time - start_time), kfree_loops,
659 rcuperf_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
660 (mem_begin - mem_during) >> (20 - PAGE_SHIFT));
661
662 if (shutdown) {
663 smp_mb(); /* Assign before wake. */
664 wake_up(&shutdown_wq);
665 }
666 }
667
668 torture_kthread_stopping("kfree_perf_thread");
669 return 0;
670}
671
672static void
673kfree_perf_cleanup(void)
674{
675 int i;
676
677 if (torture_cleanup_begin())
678 return;
679
680 if (kfree_reader_tasks) {
681 for (i = 0; i < kfree_nrealthreads; i++)
682 torture_stop_kthread(kfree_perf_thread,
683 kfree_reader_tasks[i]);
684 kfree(kfree_reader_tasks);
685 }
686
687 torture_cleanup_end();
688}
689
690/*
691 * shutdown kthread. Just waits to be awakened, then shuts down system.
692 */
693static int
694kfree_perf_shutdown(void *arg)
695{
696 wait_event(shutdown_wq,
697 atomic_read(&n_kfree_perf_thread_ended) >= kfree_nrealthreads);
698
699 smp_mb(); /* Wake before output. */
700
701 kfree_perf_cleanup();
702 kernel_power_off();
703 return -EINVAL;
704}
705
706static int __init
707kfree_perf_init(void)
708{
709 long i;
710 int firsterr = 0;
711
712 kfree_nrealthreads = compute_real(kfree_nthreads);
713 /* Start up the kthreads. */
714 if (shutdown) {
715 init_waitqueue_head(&shutdown_wq);
716 firsterr = torture_create_kthread(kfree_perf_shutdown, NULL,
717 shutdown_task);
718 if (firsterr)
719 goto unwind;
720 schedule_timeout_uninterruptible(1);
721 }
722
723 pr_alert("kfree object size=%zu\n", kfree_mult * sizeof(struct kfree_obj));
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 /* Process args and tell the world that the perf'er is on the job. */
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 /* Start up the kthreads. */
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);