1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Read-Copy Update module-based scalability-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 #include <linux/rcupdate_trace.h>
42
43 #include "rcu.h"
44
45 MODULE_LICENSE("GPL");
46 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
47
48 #define SCALE_FLAG "-scale:"
49 #define SCALEOUT_STRING(s) \
50 pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s)
51 #define VERBOSE_SCALEOUT_STRING(s) \
52 do { if (verbose) pr_alert("%s" SCALE_FLAG " %s\n", scale_type, s); } while (0)
53 #define SCALEOUT_ERRSTRING(s) \
54 pr_alert("%s" SCALE_FLAG "!!! %s\n", scale_type, s)
55
56 /*
57 * The intended use cases for the nreaders and nwriters module parameters
58 * are as follows:
59 *
60 * 1. Specify only the nr_cpus kernel boot parameter. This will
61 * set both nreaders and nwriters to the value specified by
62 * nr_cpus for a mixed reader/writer test.
63 *
64 * 2. Specify the nr_cpus kernel boot parameter, but set
65 * rcuscale.nreaders to zero. This will set nwriters to the
66 * value specified by nr_cpus for an update-only test.
67 *
68 * 3. Specify the nr_cpus kernel boot parameter, but set
69 * rcuscale.nwriters to zero. This will set nreaders to the
70 * value specified by nr_cpus for a read-only test.
71 *
72 * Various other use cases may of course be specified.
73 *
74 * Note that this test's readers are intended only as a test load for
75 * the writers. The reader scalability statistics will be overly
76 * pessimistic due to the per-critical-section interrupt disabling,
77 * test-end checks, and the pair of calls through pointers.
78 */
79
80 #ifdef MODULE
81 # define RCUSCALE_SHUTDOWN 0
82 #else
83 # define RCUSCALE_SHUTDOWN 1
84 #endif
85
86 torture_param(bool, gp_async, false, "Use asynchronous GP wait primitives");
87 torture_param(int, gp_async_max, 1000, "Max # outstanding waits per reader");
88 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
89 torture_param(int, holdoff, 10, "Holdoff time before test start (s)");
90 torture_param(int, nreaders, -1, "Number of RCU reader threads");
91 torture_param(int, nwriters, -1, "Number of RCU updater threads");
92 torture_param(bool, shutdown, RCUSCALE_SHUTDOWN,
93 "Shutdown at end of scalability tests.");
94 torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
95 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
96 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() scale test?");
97 torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
98
99 static char *scale_type = "rcu";
100 module_param(scale_type, charp, 0444);
101 MODULE_PARM_DESC(scale_type, "Type of RCU to scalability-test (rcu, srcu, ...)");
102
103 static int nrealreaders;
104 static int nrealwriters;
105 static struct task_struct **writer_tasks;
106 static struct task_struct **reader_tasks;
107 static struct task_struct *shutdown_task;
108
109 static u64 **writer_durations;
110 static int *writer_n_durations;
111 static atomic_t n_rcu_scale_reader_started;
112 static atomic_t n_rcu_scale_writer_started;
113 static atomic_t n_rcu_scale_writer_finished;
114 static wait_queue_head_t shutdown_wq;
115 static u64 t_rcu_scale_writer_started;
116 static u64 t_rcu_scale_writer_finished;
117 static unsigned long b_rcu_gp_test_started;
118 static unsigned long b_rcu_gp_test_finished;
119 static DEFINE_PER_CPU(atomic_t, n_async_inflight);
120
121 #define MAX_MEAS 10000
122 #define MIN_MEAS 100
123
124 /*
125 * Operations vector for selecting different types of tests.
126 */
127
128 struct rcu_scale_ops {
129 int ptype;
130 void (*init)(void);
131 void (*cleanup)(void);
132 int (*readlock)(void);
133 void (*readunlock)(int idx);
134 unsigned long (*get_gp_seq)(void);
135 unsigned long (*gp_diff)(unsigned long new, unsigned long old);
136 unsigned long (*exp_completed)(void);
137 void (*async)(struct rcu_head *head, rcu_callback_t func);
138 void (*gp_barrier)(void);
139 void (*sync)(void);
140 void (*exp_sync)(void);
141 const char *name;
142 };
143
144 static struct rcu_scale_ops *cur_ops;
145
146 /*
147 * Definitions for rcu scalability testing.
148 */
149
rcu_scale_read_lock(void)150 static int rcu_scale_read_lock(void) __acquires(RCU)
151 {
152 rcu_read_lock();
153 return 0;
154 }
155
rcu_scale_read_unlock(int idx)156 static void rcu_scale_read_unlock(int idx) __releases(RCU)
157 {
158 rcu_read_unlock();
159 }
160
rcu_no_completed(void)161 static unsigned long __maybe_unused rcu_no_completed(void)
162 {
163 return 0;
164 }
165
rcu_sync_scale_init(void)166 static void rcu_sync_scale_init(void)
167 {
168 }
169
170 static struct rcu_scale_ops rcu_ops = {
171 .ptype = RCU_FLAVOR,
172 .init = rcu_sync_scale_init,
173 .readlock = rcu_scale_read_lock,
174 .readunlock = rcu_scale_read_unlock,
175 .get_gp_seq = rcu_get_gp_seq,
176 .gp_diff = rcu_seq_diff,
177 .exp_completed = rcu_exp_batches_completed,
178 .async = call_rcu_hurry,
179 .gp_barrier = rcu_barrier,
180 .sync = synchronize_rcu,
181 .exp_sync = synchronize_rcu_expedited,
182 .name = "rcu"
183 };
184
185 /*
186 * Definitions for srcu scalability testing.
187 */
188
189 DEFINE_STATIC_SRCU(srcu_ctl_scale);
190 static struct srcu_struct *srcu_ctlp = &srcu_ctl_scale;
191
srcu_scale_read_lock(void)192 static int srcu_scale_read_lock(void) __acquires(srcu_ctlp)
193 {
194 return srcu_read_lock(srcu_ctlp);
195 }
196
srcu_scale_read_unlock(int idx)197 static void srcu_scale_read_unlock(int idx) __releases(srcu_ctlp)
198 {
199 srcu_read_unlock(srcu_ctlp, idx);
200 }
201
srcu_scale_completed(void)202 static unsigned long srcu_scale_completed(void)
203 {
204 return srcu_batches_completed(srcu_ctlp);
205 }
206
srcu_call_rcu(struct rcu_head * head,rcu_callback_t func)207 static void srcu_call_rcu(struct rcu_head *head, rcu_callback_t func)
208 {
209 call_srcu(srcu_ctlp, head, func);
210 }
211
srcu_rcu_barrier(void)212 static void srcu_rcu_barrier(void)
213 {
214 srcu_barrier(srcu_ctlp);
215 }
216
srcu_scale_synchronize(void)217 static void srcu_scale_synchronize(void)
218 {
219 synchronize_srcu(srcu_ctlp);
220 }
221
srcu_scale_synchronize_expedited(void)222 static void srcu_scale_synchronize_expedited(void)
223 {
224 synchronize_srcu_expedited(srcu_ctlp);
225 }
226
227 static struct rcu_scale_ops srcu_ops = {
228 .ptype = SRCU_FLAVOR,
229 .init = rcu_sync_scale_init,
230 .readlock = srcu_scale_read_lock,
231 .readunlock = srcu_scale_read_unlock,
232 .get_gp_seq = srcu_scale_completed,
233 .gp_diff = rcu_seq_diff,
234 .exp_completed = srcu_scale_completed,
235 .async = srcu_call_rcu,
236 .gp_barrier = srcu_rcu_barrier,
237 .sync = srcu_scale_synchronize,
238 .exp_sync = srcu_scale_synchronize_expedited,
239 .name = "srcu"
240 };
241
242 static struct srcu_struct srcud;
243
srcu_sync_scale_init(void)244 static void srcu_sync_scale_init(void)
245 {
246 srcu_ctlp = &srcud;
247 init_srcu_struct(srcu_ctlp);
248 }
249
srcu_sync_scale_cleanup(void)250 static void srcu_sync_scale_cleanup(void)
251 {
252 cleanup_srcu_struct(srcu_ctlp);
253 }
254
255 static struct rcu_scale_ops srcud_ops = {
256 .ptype = SRCU_FLAVOR,
257 .init = srcu_sync_scale_init,
258 .cleanup = srcu_sync_scale_cleanup,
259 .readlock = srcu_scale_read_lock,
260 .readunlock = srcu_scale_read_unlock,
261 .get_gp_seq = srcu_scale_completed,
262 .gp_diff = rcu_seq_diff,
263 .exp_completed = srcu_scale_completed,
264 .async = srcu_call_rcu,
265 .gp_barrier = srcu_rcu_barrier,
266 .sync = srcu_scale_synchronize,
267 .exp_sync = srcu_scale_synchronize_expedited,
268 .name = "srcud"
269 };
270
271 #ifdef CONFIG_TASKS_RCU
272
273 /*
274 * Definitions for RCU-tasks scalability testing.
275 */
276
tasks_scale_read_lock(void)277 static int tasks_scale_read_lock(void)
278 {
279 return 0;
280 }
281
tasks_scale_read_unlock(int idx)282 static void tasks_scale_read_unlock(int idx)
283 {
284 }
285
286 static struct rcu_scale_ops tasks_ops = {
287 .ptype = RCU_TASKS_FLAVOR,
288 .init = rcu_sync_scale_init,
289 .readlock = tasks_scale_read_lock,
290 .readunlock = tasks_scale_read_unlock,
291 .get_gp_seq = rcu_no_completed,
292 .gp_diff = rcu_seq_diff,
293 .async = call_rcu_tasks,
294 .gp_barrier = rcu_barrier_tasks,
295 .sync = synchronize_rcu_tasks,
296 .exp_sync = synchronize_rcu_tasks,
297 .name = "tasks"
298 };
299
300 #define TASKS_OPS &tasks_ops,
301
302 #else // #ifdef CONFIG_TASKS_RCU
303
304 #define TASKS_OPS
305
306 #endif // #else // #ifdef CONFIG_TASKS_RCU
307
308 #ifdef CONFIG_TASKS_TRACE_RCU
309
310 /*
311 * Definitions for RCU-tasks-trace scalability testing.
312 */
313
tasks_trace_scale_read_lock(void)314 static int tasks_trace_scale_read_lock(void)
315 {
316 rcu_read_lock_trace();
317 return 0;
318 }
319
tasks_trace_scale_read_unlock(int idx)320 static void tasks_trace_scale_read_unlock(int idx)
321 {
322 rcu_read_unlock_trace();
323 }
324
325 static struct rcu_scale_ops tasks_tracing_ops = {
326 .ptype = RCU_TASKS_FLAVOR,
327 .init = rcu_sync_scale_init,
328 .readlock = tasks_trace_scale_read_lock,
329 .readunlock = tasks_trace_scale_read_unlock,
330 .get_gp_seq = rcu_no_completed,
331 .gp_diff = rcu_seq_diff,
332 .async = call_rcu_tasks_trace,
333 .gp_barrier = rcu_barrier_tasks_trace,
334 .sync = synchronize_rcu_tasks_trace,
335 .exp_sync = synchronize_rcu_tasks_trace,
336 .name = "tasks-tracing"
337 };
338
339 #define TASKS_TRACING_OPS &tasks_tracing_ops,
340
341 #else // #ifdef CONFIG_TASKS_TRACE_RCU
342
343 #define TASKS_TRACING_OPS
344
345 #endif // #else // #ifdef CONFIG_TASKS_TRACE_RCU
346
rcuscale_seq_diff(unsigned long new,unsigned long old)347 static unsigned long rcuscale_seq_diff(unsigned long new, unsigned long old)
348 {
349 if (!cur_ops->gp_diff)
350 return new - old;
351 return cur_ops->gp_diff(new, old);
352 }
353
354 /*
355 * If scalability tests complete, wait for shutdown to commence.
356 */
rcu_scale_wait_shutdown(void)357 static void rcu_scale_wait_shutdown(void)
358 {
359 cond_resched_tasks_rcu_qs();
360 if (atomic_read(&n_rcu_scale_writer_finished) < nrealwriters)
361 return;
362 while (!torture_must_stop())
363 schedule_timeout_uninterruptible(1);
364 }
365
366 /*
367 * RCU scalability reader kthread. Repeatedly does empty RCU read-side
368 * critical section, minimizing update-side interference. However, the
369 * point of this test is not to evaluate reader scalability, but instead
370 * to serve as a test load for update-side scalability testing.
371 */
372 static int
rcu_scale_reader(void * arg)373 rcu_scale_reader(void *arg)
374 {
375 unsigned long flags;
376 int idx;
377 long me = (long)arg;
378
379 VERBOSE_SCALEOUT_STRING("rcu_scale_reader task started");
380 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
381 set_user_nice(current, MAX_NICE);
382 atomic_inc(&n_rcu_scale_reader_started);
383
384 do {
385 local_irq_save(flags);
386 idx = cur_ops->readlock();
387 cur_ops->readunlock(idx);
388 local_irq_restore(flags);
389 rcu_scale_wait_shutdown();
390 } while (!torture_must_stop());
391 torture_kthread_stopping("rcu_scale_reader");
392 return 0;
393 }
394
395 /*
396 * Callback function for asynchronous grace periods from rcu_scale_writer().
397 */
rcu_scale_async_cb(struct rcu_head * rhp)398 static void rcu_scale_async_cb(struct rcu_head *rhp)
399 {
400 atomic_dec(this_cpu_ptr(&n_async_inflight));
401 kfree(rhp);
402 }
403
404 /*
405 * RCU scale writer kthread. Repeatedly does a grace period.
406 */
407 static int
rcu_scale_writer(void * arg)408 rcu_scale_writer(void *arg)
409 {
410 int i = 0;
411 int i_max;
412 long me = (long)arg;
413 struct rcu_head *rhp = NULL;
414 bool started = false, done = false, alldone = false;
415 u64 t;
416 u64 *wdp;
417 u64 *wdpp = writer_durations[me];
418
419 VERBOSE_SCALEOUT_STRING("rcu_scale_writer task started");
420 WARN_ON(!wdpp);
421 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
422 current->flags |= PF_NO_SETAFFINITY;
423 sched_set_fifo_low(current);
424
425 if (holdoff)
426 schedule_timeout_idle(holdoff * HZ);
427
428 /*
429 * Wait until rcu_end_inkernel_boot() is called for normal GP tests
430 * so that RCU is not always expedited for normal GP tests.
431 * The system_state test is approximate, but works well in practice.
432 */
433 while (!gp_exp && system_state != SYSTEM_RUNNING)
434 schedule_timeout_uninterruptible(1);
435
436 t = ktime_get_mono_fast_ns();
437 if (atomic_inc_return(&n_rcu_scale_writer_started) >= nrealwriters) {
438 t_rcu_scale_writer_started = t;
439 if (gp_exp) {
440 b_rcu_gp_test_started =
441 cur_ops->exp_completed() / 2;
442 } else {
443 b_rcu_gp_test_started = cur_ops->get_gp_seq();
444 }
445 }
446
447 do {
448 if (writer_holdoff)
449 udelay(writer_holdoff);
450 wdp = &wdpp[i];
451 *wdp = ktime_get_mono_fast_ns();
452 if (gp_async) {
453 retry:
454 if (!rhp)
455 rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
456 if (rhp && atomic_read(this_cpu_ptr(&n_async_inflight)) < gp_async_max) {
457 atomic_inc(this_cpu_ptr(&n_async_inflight));
458 cur_ops->async(rhp, rcu_scale_async_cb);
459 rhp = NULL;
460 } else if (!kthread_should_stop()) {
461 cur_ops->gp_barrier();
462 goto retry;
463 } else {
464 kfree(rhp); /* Because we are stopping. */
465 }
466 } else if (gp_exp) {
467 cur_ops->exp_sync();
468 } else {
469 cur_ops->sync();
470 }
471 t = ktime_get_mono_fast_ns();
472 *wdp = t - *wdp;
473 i_max = i;
474 if (!started &&
475 atomic_read(&n_rcu_scale_writer_started) >= nrealwriters)
476 started = true;
477 if (!done && i >= MIN_MEAS) {
478 done = true;
479 sched_set_normal(current, 0);
480 pr_alert("%s%s rcu_scale_writer %ld has %d measurements\n",
481 scale_type, SCALE_FLAG, me, MIN_MEAS);
482 if (atomic_inc_return(&n_rcu_scale_writer_finished) >=
483 nrealwriters) {
484 schedule_timeout_interruptible(10);
485 rcu_ftrace_dump(DUMP_ALL);
486 SCALEOUT_STRING("Test complete");
487 t_rcu_scale_writer_finished = t;
488 if (gp_exp) {
489 b_rcu_gp_test_finished =
490 cur_ops->exp_completed() / 2;
491 } else {
492 b_rcu_gp_test_finished =
493 cur_ops->get_gp_seq();
494 }
495 if (shutdown) {
496 smp_mb(); /* Assign before wake. */
497 wake_up(&shutdown_wq);
498 }
499 }
500 }
501 if (done && !alldone &&
502 atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters)
503 alldone = true;
504 if (started && !alldone && i < MAX_MEAS - 1)
505 i++;
506 rcu_scale_wait_shutdown();
507 } while (!torture_must_stop());
508 if (gp_async) {
509 cur_ops->gp_barrier();
510 }
511 writer_n_durations[me] = i_max + 1;
512 torture_kthread_stopping("rcu_scale_writer");
513 return 0;
514 }
515
516 static void
rcu_scale_print_module_parms(struct rcu_scale_ops * cur_ops,const char * tag)517 rcu_scale_print_module_parms(struct rcu_scale_ops *cur_ops, const char *tag)
518 {
519 pr_alert("%s" SCALE_FLAG
520 "--- %s: nreaders=%d nwriters=%d verbose=%d shutdown=%d\n",
521 scale_type, tag, nrealreaders, nrealwriters, verbose, shutdown);
522 }
523
524 /*
525 * Return the number if non-negative. If -1, the number of CPUs.
526 * If less than -1, that much less than the number of CPUs, but
527 * at least one.
528 */
compute_real(int n)529 static int compute_real(int n)
530 {
531 int nr;
532
533 if (n >= 0) {
534 nr = n;
535 } else {
536 nr = num_online_cpus() + 1 + n;
537 if (nr <= 0)
538 nr = 1;
539 }
540 return nr;
541 }
542
543 /*
544 * kfree_rcu() scalability tests: Start a kfree_rcu() loop on all CPUs for number
545 * of iterations and measure total time and number of GP for all iterations to complete.
546 */
547
548 torture_param(int, kfree_nthreads, -1, "Number of threads running loops of kfree_rcu().");
549 torture_param(int, kfree_alloc_num, 8000, "Number of allocations and frees done in an iteration.");
550 torture_param(int, kfree_loops, 10, "Number of loops doing kfree_alloc_num allocations and frees.");
551 torture_param(bool, kfree_rcu_test_double, false, "Do we run a kfree_rcu() double-argument scale test?");
552 torture_param(bool, kfree_rcu_test_single, false, "Do we run a kfree_rcu() single-argument scale test?");
553
554 static struct task_struct **kfree_reader_tasks;
555 static int kfree_nrealthreads;
556 static atomic_t n_kfree_scale_thread_started;
557 static atomic_t n_kfree_scale_thread_ended;
558
559 struct kfree_obj {
560 char kfree_obj[8];
561 struct rcu_head rh;
562 };
563
564 static int
kfree_scale_thread(void * arg)565 kfree_scale_thread(void *arg)
566 {
567 int i, loop = 0;
568 long me = (long)arg;
569 struct kfree_obj *alloc_ptr;
570 u64 start_time, end_time;
571 long long mem_begin, mem_during = 0;
572 bool kfree_rcu_test_both;
573 DEFINE_TORTURE_RANDOM(tr);
574
575 VERBOSE_SCALEOUT_STRING("kfree_scale_thread task started");
576 set_cpus_allowed_ptr(current, cpumask_of(me % nr_cpu_ids));
577 set_user_nice(current, MAX_NICE);
578 kfree_rcu_test_both = (kfree_rcu_test_single == kfree_rcu_test_double);
579
580 start_time = ktime_get_mono_fast_ns();
581
582 if (atomic_inc_return(&n_kfree_scale_thread_started) >= kfree_nrealthreads) {
583 if (gp_exp)
584 b_rcu_gp_test_started = cur_ops->exp_completed() / 2;
585 else
586 b_rcu_gp_test_started = cur_ops->get_gp_seq();
587 }
588
589 do {
590 if (!mem_during) {
591 mem_during = mem_begin = si_mem_available();
592 } else if (loop % (kfree_loops / 4) == 0) {
593 mem_during = (mem_during + si_mem_available()) / 2;
594 }
595
596 for (i = 0; i < kfree_alloc_num; i++) {
597 alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
598 if (!alloc_ptr)
599 return -ENOMEM;
600
601 // By default kfree_rcu_test_single and kfree_rcu_test_double are
602 // initialized to false. If both have the same value (false or true)
603 // both are randomly tested, otherwise only the one with value true
604 // is tested.
605 if ((kfree_rcu_test_single && !kfree_rcu_test_double) ||
606 (kfree_rcu_test_both && torture_random(&tr) & 0x800))
607 kfree_rcu(alloc_ptr);
608 else
609 kfree_rcu(alloc_ptr, rh);
610 }
611
612 cond_resched();
613 } while (!torture_must_stop() && ++loop < kfree_loops);
614
615 if (atomic_inc_return(&n_kfree_scale_thread_ended) >= kfree_nrealthreads) {
616 end_time = ktime_get_mono_fast_ns();
617
618 if (gp_exp)
619 b_rcu_gp_test_finished = cur_ops->exp_completed() / 2;
620 else
621 b_rcu_gp_test_finished = cur_ops->get_gp_seq();
622
623 pr_alert("Total time taken by all kfree'ers: %llu ns, loops: %d, batches: %ld, memory footprint: %lldMB\n",
624 (unsigned long long)(end_time - start_time), kfree_loops,
625 rcuscale_seq_diff(b_rcu_gp_test_finished, b_rcu_gp_test_started),
626 (mem_begin - mem_during) >> (20 - PAGE_SHIFT));
627
628 if (shutdown) {
629 smp_mb(); /* Assign before wake. */
630 wake_up(&shutdown_wq);
631 }
632 }
633
634 torture_kthread_stopping("kfree_scale_thread");
635 return 0;
636 }
637
638 static void
kfree_scale_cleanup(void)639 kfree_scale_cleanup(void)
640 {
641 int i;
642
643 if (torture_cleanup_begin())
644 return;
645
646 if (kfree_reader_tasks) {
647 for (i = 0; i < kfree_nrealthreads; i++)
648 torture_stop_kthread(kfree_scale_thread,
649 kfree_reader_tasks[i]);
650 kfree(kfree_reader_tasks);
651 }
652
653 torture_cleanup_end();
654 }
655
656 /*
657 * shutdown kthread. Just waits to be awakened, then shuts down system.
658 */
659 static int
kfree_scale_shutdown(void * arg)660 kfree_scale_shutdown(void *arg)
661 {
662 wait_event_idle(shutdown_wq,
663 atomic_read(&n_kfree_scale_thread_ended) >= kfree_nrealthreads);
664
665 smp_mb(); /* Wake before output. */
666
667 kfree_scale_cleanup();
668 kernel_power_off();
669 return -EINVAL;
670 }
671
672 static int __init
kfree_scale_init(void)673 kfree_scale_init(void)
674 {
675 long i;
676 int firsterr = 0;
677
678 kfree_nrealthreads = compute_real(kfree_nthreads);
679 /* Start up the kthreads. */
680 if (shutdown) {
681 init_waitqueue_head(&shutdown_wq);
682 firsterr = torture_create_kthread(kfree_scale_shutdown, NULL,
683 shutdown_task);
684 if (torture_init_error(firsterr))
685 goto unwind;
686 schedule_timeout_uninterruptible(1);
687 }
688
689 pr_alert("kfree object size=%zu\n", kfree_mult * sizeof(struct kfree_obj));
690
691 kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
692 GFP_KERNEL);
693 if (kfree_reader_tasks == NULL) {
694 firsterr = -ENOMEM;
695 goto unwind;
696 }
697
698 for (i = 0; i < kfree_nrealthreads; i++) {
699 firsterr = torture_create_kthread(kfree_scale_thread, (void *)i,
700 kfree_reader_tasks[i]);
701 if (torture_init_error(firsterr))
702 goto unwind;
703 }
704
705 while (atomic_read(&n_kfree_scale_thread_started) < kfree_nrealthreads)
706 schedule_timeout_uninterruptible(1);
707
708 torture_init_end();
709 return 0;
710
711 unwind:
712 torture_init_end();
713 kfree_scale_cleanup();
714 return firsterr;
715 }
716
717 static void
rcu_scale_cleanup(void)718 rcu_scale_cleanup(void)
719 {
720 int i;
721 int j;
722 int ngps = 0;
723 u64 *wdp;
724 u64 *wdpp;
725
726 /*
727 * Would like warning at start, but everything is expedited
728 * during the mid-boot phase, so have to wait till the end.
729 */
730 if (rcu_gp_is_expedited() && !rcu_gp_is_normal() && !gp_exp)
731 SCALEOUT_ERRSTRING("All grace periods expedited, no normal ones to measure!");
732 if (rcu_gp_is_normal() && gp_exp)
733 SCALEOUT_ERRSTRING("All grace periods normal, no expedited ones to measure!");
734 if (gp_exp && gp_async)
735 SCALEOUT_ERRSTRING("No expedited async GPs, so went with async!");
736
737 if (kfree_rcu_test) {
738 kfree_scale_cleanup();
739 return;
740 }
741
742 if (torture_cleanup_begin())
743 return;
744 if (!cur_ops) {
745 torture_cleanup_end();
746 return;
747 }
748
749 if (reader_tasks) {
750 for (i = 0; i < nrealreaders; i++)
751 torture_stop_kthread(rcu_scale_reader,
752 reader_tasks[i]);
753 kfree(reader_tasks);
754 }
755
756 if (writer_tasks) {
757 for (i = 0; i < nrealwriters; i++) {
758 torture_stop_kthread(rcu_scale_writer,
759 writer_tasks[i]);
760 if (!writer_n_durations)
761 continue;
762 j = writer_n_durations[i];
763 pr_alert("%s%s writer %d gps: %d\n",
764 scale_type, SCALE_FLAG, i, j);
765 ngps += j;
766 }
767 pr_alert("%s%s start: %llu end: %llu duration: %llu gps: %d batches: %ld\n",
768 scale_type, SCALE_FLAG,
769 t_rcu_scale_writer_started, t_rcu_scale_writer_finished,
770 t_rcu_scale_writer_finished -
771 t_rcu_scale_writer_started,
772 ngps,
773 rcuscale_seq_diff(b_rcu_gp_test_finished,
774 b_rcu_gp_test_started));
775 for (i = 0; i < nrealwriters; i++) {
776 if (!writer_durations)
777 break;
778 if (!writer_n_durations)
779 continue;
780 wdpp = writer_durations[i];
781 if (!wdpp)
782 continue;
783 for (j = 0; j < writer_n_durations[i]; j++) {
784 wdp = &wdpp[j];
785 pr_alert("%s%s %4d writer-duration: %5d %llu\n",
786 scale_type, SCALE_FLAG,
787 i, j, *wdp);
788 if (j % 100 == 0)
789 schedule_timeout_uninterruptible(1);
790 }
791 kfree(writer_durations[i]);
792 }
793 kfree(writer_tasks);
794 kfree(writer_durations);
795 kfree(writer_n_durations);
796 }
797
798 /* Do torture-type-specific cleanup operations. */
799 if (cur_ops->cleanup != NULL)
800 cur_ops->cleanup();
801
802 torture_cleanup_end();
803 }
804
805 /*
806 * RCU scalability shutdown kthread. Just waits to be awakened, then shuts
807 * down system.
808 */
809 static int
rcu_scale_shutdown(void * arg)810 rcu_scale_shutdown(void *arg)
811 {
812 wait_event_idle(shutdown_wq, atomic_read(&n_rcu_scale_writer_finished) >= nrealwriters);
813 smp_mb(); /* Wake before output. */
814 rcu_scale_cleanup();
815 kernel_power_off();
816 return -EINVAL;
817 }
818
819 static int __init
rcu_scale_init(void)820 rcu_scale_init(void)
821 {
822 long i;
823 int firsterr = 0;
824 static struct rcu_scale_ops *scale_ops[] = {
825 &rcu_ops, &srcu_ops, &srcud_ops, TASKS_OPS TASKS_TRACING_OPS
826 };
827
828 if (!torture_init_begin(scale_type, verbose))
829 return -EBUSY;
830
831 /* Process args and announce that the scalability'er is on the job. */
832 for (i = 0; i < ARRAY_SIZE(scale_ops); i++) {
833 cur_ops = scale_ops[i];
834 if (strcmp(scale_type, cur_ops->name) == 0)
835 break;
836 }
837 if (i == ARRAY_SIZE(scale_ops)) {
838 pr_alert("rcu-scale: invalid scale type: \"%s\"\n", scale_type);
839 pr_alert("rcu-scale types:");
840 for (i = 0; i < ARRAY_SIZE(scale_ops); i++)
841 pr_cont(" %s", scale_ops[i]->name);
842 pr_cont("\n");
843 firsterr = -EINVAL;
844 cur_ops = NULL;
845 goto unwind;
846 }
847 if (cur_ops->init)
848 cur_ops->init();
849
850 if (kfree_rcu_test)
851 return kfree_scale_init();
852
853 nrealwriters = compute_real(nwriters);
854 nrealreaders = compute_real(nreaders);
855 atomic_set(&n_rcu_scale_reader_started, 0);
856 atomic_set(&n_rcu_scale_writer_started, 0);
857 atomic_set(&n_rcu_scale_writer_finished, 0);
858 rcu_scale_print_module_parms(cur_ops, "Start of test");
859
860 /* Start up the kthreads. */
861
862 if (shutdown) {
863 init_waitqueue_head(&shutdown_wq);
864 firsterr = torture_create_kthread(rcu_scale_shutdown, NULL,
865 shutdown_task);
866 if (torture_init_error(firsterr))
867 goto unwind;
868 schedule_timeout_uninterruptible(1);
869 }
870 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
871 GFP_KERNEL);
872 if (reader_tasks == NULL) {
873 SCALEOUT_ERRSTRING("out of memory");
874 firsterr = -ENOMEM;
875 goto unwind;
876 }
877 for (i = 0; i < nrealreaders; i++) {
878 firsterr = torture_create_kthread(rcu_scale_reader, (void *)i,
879 reader_tasks[i]);
880 if (torture_init_error(firsterr))
881 goto unwind;
882 }
883 while (atomic_read(&n_rcu_scale_reader_started) < nrealreaders)
884 schedule_timeout_uninterruptible(1);
885 writer_tasks = kcalloc(nrealwriters, sizeof(reader_tasks[0]),
886 GFP_KERNEL);
887 writer_durations = kcalloc(nrealwriters, sizeof(*writer_durations),
888 GFP_KERNEL);
889 writer_n_durations =
890 kcalloc(nrealwriters, sizeof(*writer_n_durations),
891 GFP_KERNEL);
892 if (!writer_tasks || !writer_durations || !writer_n_durations) {
893 SCALEOUT_ERRSTRING("out of memory");
894 firsterr = -ENOMEM;
895 goto unwind;
896 }
897 for (i = 0; i < nrealwriters; i++) {
898 writer_durations[i] =
899 kcalloc(MAX_MEAS, sizeof(*writer_durations[i]),
900 GFP_KERNEL);
901 if (!writer_durations[i]) {
902 firsterr = -ENOMEM;
903 goto unwind;
904 }
905 firsterr = torture_create_kthread(rcu_scale_writer, (void *)i,
906 writer_tasks[i]);
907 if (torture_init_error(firsterr))
908 goto unwind;
909 }
910 torture_init_end();
911 return 0;
912
913 unwind:
914 torture_init_end();
915 rcu_scale_cleanup();
916 if (shutdown) {
917 WARN_ON(!IS_MODULE(CONFIG_RCU_SCALE_TEST));
918 kernel_power_off();
919 }
920 return firsterr;
921 }
922
923 module_init(rcu_scale_init);
924 module_exit(rcu_scale_cleanup);
925