FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_lock.c
1 /*-
2 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 /*
28 * This module holds the global variables and functions used to maintain
29 * lock_object structures.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34
35 #include "opt_ddb.h"
36 #include "opt_mprof.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/ktr.h>
42 #include <sys/lock.h>
43 #include <sys/lock_profile.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/pcpu.h>
47 #include <sys/proc.h>
48 #include <sys/sbuf.h>
49 #include <sys/sched.h>
50 #include <sys/smp.h>
51 #include <sys/sysctl.h>
52
53 #ifdef DDB
54 #include <ddb/ddb.h>
55 #endif
56
57 #include <machine/cpufunc.h>
58
59 CTASSERT(LOCK_CLASS_MAX == 15);
60
61 struct lock_class *lock_classes[LOCK_CLASS_MAX + 1] = {
62 &lock_class_mtx_spin,
63 &lock_class_mtx_sleep,
64 &lock_class_sx,
65 &lock_class_rm,
66 &lock_class_rm_sleepable,
67 &lock_class_rw,
68 &lock_class_lockmgr,
69 };
70
71 void
72 lock_init(struct lock_object *lock, struct lock_class *class, const char *name,
73 const char *type, int flags)
74 {
75 int i;
76
77 /* Check for double-init and zero object. */
78 KASSERT(!lock_initalized(lock), ("lock \"%s\" %p already initialized",
79 name, lock));
80
81 /* Look up lock class to find its index. */
82 for (i = 0; i < LOCK_CLASS_MAX; i++)
83 if (lock_classes[i] == class) {
84 lock->lo_flags = i << LO_CLASSSHIFT;
85 break;
86 }
87 KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class));
88
89 /* Initialize the lock object. */
90 lock->lo_name = name;
91 lock->lo_flags |= flags | LO_INITIALIZED;
92 LOCK_LOG_INIT(lock, 0);
93 WITNESS_INIT(lock, (type != NULL) ? type : name);
94 }
95
96 void
97 lock_destroy(struct lock_object *lock)
98 {
99
100 KASSERT(lock_initalized(lock), ("lock %p is not initialized", lock));
101 WITNESS_DESTROY(lock);
102 LOCK_LOG_DESTROY(lock, 0);
103 lock->lo_flags &= ~LO_INITIALIZED;
104 }
105
106 #ifdef DDB
107 DB_SHOW_COMMAND(lock, db_show_lock)
108 {
109 struct lock_object *lock;
110 struct lock_class *class;
111
112 if (!have_addr)
113 return;
114 lock = (struct lock_object *)addr;
115 if (LO_CLASSINDEX(lock) > LOCK_CLASS_MAX) {
116 db_printf("Unknown lock class: %d\n", LO_CLASSINDEX(lock));
117 return;
118 }
119 class = LOCK_CLASS(lock);
120 db_printf(" class: %s\n", class->lc_name);
121 db_printf(" name: %s\n", lock->lo_name);
122 class->lc_ddb_show(lock);
123 }
124 #endif
125
126 #ifdef LOCK_PROFILING
127
128 /*
129 * One object per-thread for each lock the thread owns. Tracks individual
130 * lock instances.
131 */
132 struct lock_profile_object {
133 LIST_ENTRY(lock_profile_object) lpo_link;
134 struct lock_object *lpo_obj;
135 const char *lpo_file;
136 int lpo_line;
137 uint16_t lpo_ref;
138 uint16_t lpo_cnt;
139 uint64_t lpo_acqtime;
140 uint64_t lpo_waittime;
141 u_int lpo_contest_locking;
142 };
143
144 /*
145 * One lock_prof for each (file, line, lock object) triple.
146 */
147 struct lock_prof {
148 SLIST_ENTRY(lock_prof) link;
149 struct lock_class *class;
150 const char *file;
151 const char *name;
152 int line;
153 int ticks;
154 uintmax_t cnt_wait_max;
155 uintmax_t cnt_max;
156 uintmax_t cnt_tot;
157 uintmax_t cnt_wait;
158 uintmax_t cnt_cur;
159 uintmax_t cnt_contest_locking;
160 };
161
162 SLIST_HEAD(lphead, lock_prof);
163
164 #define LPROF_HASH_SIZE 4096
165 #define LPROF_HASH_MASK (LPROF_HASH_SIZE - 1)
166 #define LPROF_CACHE_SIZE 4096
167
168 /*
169 * Array of objects and profs for each type of object for each cpu. Spinlocks
170 * are handled separately because a thread may be preempted and acquire a
171 * spinlock while in the lock profiling code of a non-spinlock. In this way
172 * we only need a critical section to protect the per-cpu lists.
173 */
174 struct lock_prof_type {
175 struct lphead lpt_lpalloc;
176 struct lpohead lpt_lpoalloc;
177 struct lphead lpt_hash[LPROF_HASH_SIZE];
178 struct lock_prof lpt_prof[LPROF_CACHE_SIZE];
179 struct lock_profile_object lpt_objs[LPROF_CACHE_SIZE];
180 };
181
182 struct lock_prof_cpu {
183 struct lock_prof_type lpc_types[2]; /* One for spin one for other. */
184 };
185
186 struct lock_prof_cpu *lp_cpu[MAXCPU];
187
188 volatile int lock_prof_enable = 0;
189 static volatile int lock_prof_resetting;
190
191 #define LPROF_SBUF_SIZE 256
192
193 static int lock_prof_rejected;
194 static int lock_prof_skipspin;
195 static int lock_prof_skipcount;
196
197 #ifndef USE_CPU_NANOSECONDS
198 uint64_t
199 nanoseconds(void)
200 {
201 struct bintime bt;
202 uint64_t ns;
203
204 binuptime(&bt);
205 /* From bintime2timespec */
206 ns = bt.sec * (uint64_t)1000000000;
207 ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32;
208 return (ns);
209 }
210 #endif
211
212 static void
213 lock_prof_init_type(struct lock_prof_type *type)
214 {
215 int i;
216
217 SLIST_INIT(&type->lpt_lpalloc);
218 LIST_INIT(&type->lpt_lpoalloc);
219 for (i = 0; i < LPROF_CACHE_SIZE; i++) {
220 SLIST_INSERT_HEAD(&type->lpt_lpalloc, &type->lpt_prof[i],
221 link);
222 LIST_INSERT_HEAD(&type->lpt_lpoalloc, &type->lpt_objs[i],
223 lpo_link);
224 }
225 }
226
227 static void
228 lock_prof_init(void *arg)
229 {
230 int cpu;
231
232 for (cpu = 0; cpu <= mp_maxid; cpu++) {
233 lp_cpu[cpu] = malloc(sizeof(*lp_cpu[cpu]), M_DEVBUF,
234 M_WAITOK | M_ZERO);
235 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[0]);
236 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[1]);
237 }
238 }
239 SYSINIT(lockprof, SI_SUB_SMP, SI_ORDER_ANY, lock_prof_init, NULL);
240
241 /*
242 * To be certain that lock profiling has idled on all cpus before we
243 * reset, we schedule the resetting thread on all active cpus. Since
244 * all operations happen within critical sections we can be sure that
245 * it is safe to zero the profiling structures.
246 */
247 static void
248 lock_prof_idle(void)
249 {
250 struct thread *td;
251 int cpu;
252
253 td = curthread;
254 thread_lock(td);
255 CPU_FOREACH(cpu) {
256 sched_bind(td, cpu);
257 }
258 sched_unbind(td);
259 thread_unlock(td);
260 }
261
262 static void
263 lock_prof_reset_wait(void)
264 {
265
266 /*
267 * Spin relinquishing our cpu so that lock_prof_idle may
268 * run on it.
269 */
270 while (lock_prof_resetting)
271 sched_relinquish(curthread);
272 }
273
274 static void
275 lock_prof_reset(void)
276 {
277 struct lock_prof_cpu *lpc;
278 int enabled, i, cpu;
279
280 /*
281 * We not only race with acquiring and releasing locks but also
282 * thread exit. To be certain that threads exit without valid head
283 * pointers they must see resetting set before enabled is cleared.
284 * Otherwise a lock may not be removed from a per-thread list due
285 * to disabled being set but not wait for reset() to remove it below.
286 */
287 atomic_store_rel_int(&lock_prof_resetting, 1);
288 enabled = lock_prof_enable;
289 lock_prof_enable = 0;
290 lock_prof_idle();
291 /*
292 * Some objects may have migrated between CPUs. Clear all links
293 * before we zero the structures. Some items may still be linked
294 * into per-thread lists as well.
295 */
296 for (cpu = 0; cpu <= mp_maxid; cpu++) {
297 lpc = lp_cpu[cpu];
298 for (i = 0; i < LPROF_CACHE_SIZE; i++) {
299 LIST_REMOVE(&lpc->lpc_types[0].lpt_objs[i], lpo_link);
300 LIST_REMOVE(&lpc->lpc_types[1].lpt_objs[i], lpo_link);
301 }
302 }
303 for (cpu = 0; cpu <= mp_maxid; cpu++) {
304 lpc = lp_cpu[cpu];
305 bzero(lpc, sizeof(*lpc));
306 lock_prof_init_type(&lpc->lpc_types[0]);
307 lock_prof_init_type(&lpc->lpc_types[1]);
308 }
309 atomic_store_rel_int(&lock_prof_resetting, 0);
310 lock_prof_enable = enabled;
311 }
312
313 static void
314 lock_prof_output(struct lock_prof *lp, struct sbuf *sb)
315 {
316 const char *p;
317
318 for (p = lp->file; p != NULL && strncmp(p, "../", 3) == 0; p += 3);
319 sbuf_printf(sb,
320 "%8ju %9ju %11ju %11ju %11ju %6ju %6ju %2ju %6ju %s:%d (%s:%s)\n",
321 lp->cnt_max / 1000, lp->cnt_wait_max / 1000, lp->cnt_tot / 1000,
322 lp->cnt_wait / 1000, lp->cnt_cur,
323 lp->cnt_cur == 0 ? (uintmax_t)0 :
324 lp->cnt_tot / (lp->cnt_cur * 1000),
325 lp->cnt_cur == 0 ? (uintmax_t)0 :
326 lp->cnt_wait / (lp->cnt_cur * 1000),
327 (uintmax_t)0, lp->cnt_contest_locking,
328 p, lp->line, lp->class->lc_name, lp->name);
329 }
330
331 static void
332 lock_prof_sum(struct lock_prof *match, struct lock_prof *dst, int hash,
333 int spin, int t)
334 {
335 struct lock_prof_type *type;
336 struct lock_prof *l;
337 int cpu;
338
339 dst->file = match->file;
340 dst->line = match->line;
341 dst->class = match->class;
342 dst->name = match->name;
343
344 for (cpu = 0; cpu <= mp_maxid; cpu++) {
345 if (lp_cpu[cpu] == NULL)
346 continue;
347 type = &lp_cpu[cpu]->lpc_types[spin];
348 SLIST_FOREACH(l, &type->lpt_hash[hash], link) {
349 if (l->ticks == t)
350 continue;
351 if (l->file != match->file || l->line != match->line ||
352 l->name != match->name)
353 continue;
354 l->ticks = t;
355 if (l->cnt_max > dst->cnt_max)
356 dst->cnt_max = l->cnt_max;
357 if (l->cnt_wait_max > dst->cnt_wait_max)
358 dst->cnt_wait_max = l->cnt_wait_max;
359 dst->cnt_tot += l->cnt_tot;
360 dst->cnt_wait += l->cnt_wait;
361 dst->cnt_cur += l->cnt_cur;
362 dst->cnt_contest_locking += l->cnt_contest_locking;
363 }
364 }
365
366 }
367
368 static void
369 lock_prof_type_stats(struct lock_prof_type *type, struct sbuf *sb, int spin,
370 int t)
371 {
372 struct lock_prof *l;
373 int i;
374
375 for (i = 0; i < LPROF_HASH_SIZE; ++i) {
376 SLIST_FOREACH(l, &type->lpt_hash[i], link) {
377 struct lock_prof lp = {};
378
379 if (l->ticks == t)
380 continue;
381 lock_prof_sum(l, &lp, i, spin, t);
382 lock_prof_output(&lp, sb);
383 }
384 }
385 }
386
387 static int
388 dump_lock_prof_stats(SYSCTL_HANDLER_ARGS)
389 {
390 struct sbuf *sb;
391 int error, cpu, t;
392 int enabled;
393
394 error = sysctl_wire_old_buffer(req, 0);
395 if (error != 0)
396 return (error);
397 sb = sbuf_new_for_sysctl(NULL, NULL, LPROF_SBUF_SIZE, req);
398 sbuf_printf(sb, "\n%8s %9s %11s %11s %11s %6s %6s %2s %6s %s\n",
399 "max", "wait_max", "total", "wait_total", "count", "avg", "wait_avg", "cnt_hold", "cnt_lock", "name");
400 enabled = lock_prof_enable;
401 lock_prof_enable = 0;
402 lock_prof_idle();
403 t = ticks;
404 for (cpu = 0; cpu <= mp_maxid; cpu++) {
405 if (lp_cpu[cpu] == NULL)
406 continue;
407 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[0], sb, 0, t);
408 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[1], sb, 1, t);
409 }
410 lock_prof_enable = enabled;
411
412 error = sbuf_finish(sb);
413 /* Output a trailing NUL. */
414 if (error == 0)
415 error = SYSCTL_OUT(req, "", 1);
416 sbuf_delete(sb);
417 return (error);
418 }
419
420 static int
421 enable_lock_prof(SYSCTL_HANDLER_ARGS)
422 {
423 int error, v;
424
425 v = lock_prof_enable;
426 error = sysctl_handle_int(oidp, &v, v, req);
427 if (error)
428 return (error);
429 if (req->newptr == NULL)
430 return (error);
431 if (v == lock_prof_enable)
432 return (0);
433 if (v == 1)
434 lock_prof_reset();
435 lock_prof_enable = !!v;
436
437 return (0);
438 }
439
440 static int
441 reset_lock_prof_stats(SYSCTL_HANDLER_ARGS)
442 {
443 int error, v;
444
445 v = 0;
446 error = sysctl_handle_int(oidp, &v, 0, req);
447 if (error)
448 return (error);
449 if (req->newptr == NULL)
450 return (error);
451 if (v == 0)
452 return (0);
453 lock_prof_reset();
454
455 return (0);
456 }
457
458 static struct lock_prof *
459 lock_profile_lookup(struct lock_object *lo, int spin, const char *file,
460 int line)
461 {
462 const char *unknown = "(unknown)";
463 struct lock_prof_type *type;
464 struct lock_prof *lp;
465 struct lphead *head;
466 const char *p;
467 u_int hash;
468
469 p = file;
470 if (p == NULL || *p == '\0')
471 p = unknown;
472 hash = (uintptr_t)lo->lo_name * 31 + (uintptr_t)p * 31 + line;
473 hash &= LPROF_HASH_MASK;
474 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin];
475 head = &type->lpt_hash[hash];
476 SLIST_FOREACH(lp, head, link) {
477 if (lp->line == line && lp->file == p &&
478 lp->name == lo->lo_name)
479 return (lp);
480
481 }
482 lp = SLIST_FIRST(&type->lpt_lpalloc);
483 if (lp == NULL) {
484 lock_prof_rejected++;
485 return (lp);
486 }
487 SLIST_REMOVE_HEAD(&type->lpt_lpalloc, link);
488 lp->file = p;
489 lp->line = line;
490 lp->class = LOCK_CLASS(lo);
491 lp->name = lo->lo_name;
492 SLIST_INSERT_HEAD(&type->lpt_hash[hash], lp, link);
493 return (lp);
494 }
495
496 static struct lock_profile_object *
497 lock_profile_object_lookup(struct lock_object *lo, int spin, const char *file,
498 int line)
499 {
500 struct lock_profile_object *l;
501 struct lock_prof_type *type;
502 struct lpohead *head;
503
504 head = &curthread->td_lprof[spin];
505 LIST_FOREACH(l, head, lpo_link)
506 if (l->lpo_obj == lo && l->lpo_file == file &&
507 l->lpo_line == line)
508 return (l);
509 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin];
510 l = LIST_FIRST(&type->lpt_lpoalloc);
511 if (l == NULL) {
512 lock_prof_rejected++;
513 return (NULL);
514 }
515 LIST_REMOVE(l, lpo_link);
516 l->lpo_obj = lo;
517 l->lpo_file = file;
518 l->lpo_line = line;
519 l->lpo_cnt = 0;
520 LIST_INSERT_HEAD(head, l, lpo_link);
521
522 return (l);
523 }
524
525 void
526 lock_profile_obtain_lock_success(struct lock_object *lo, int contested,
527 uint64_t waittime, const char *file, int line)
528 {
529 static int lock_prof_count;
530 struct lock_profile_object *l;
531 int spin;
532
533 if (SCHEDULER_STOPPED())
534 return;
535
536 /* don't reset the timer when/if recursing */
537 if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE))
538 return;
539 if (lock_prof_skipcount &&
540 (++lock_prof_count % lock_prof_skipcount) != 0)
541 return;
542 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0;
543 if (spin && lock_prof_skipspin == 1)
544 return;
545 critical_enter();
546 /* Recheck enabled now that we're in a critical section. */
547 if (lock_prof_enable == 0)
548 goto out;
549 l = lock_profile_object_lookup(lo, spin, file, line);
550 if (l == NULL)
551 goto out;
552 l->lpo_cnt++;
553 if (++l->lpo_ref > 1)
554 goto out;
555 l->lpo_contest_locking = contested;
556 l->lpo_acqtime = nanoseconds();
557 if (waittime && (l->lpo_acqtime > waittime))
558 l->lpo_waittime = l->lpo_acqtime - waittime;
559 else
560 l->lpo_waittime = 0;
561 out:
562 critical_exit();
563 }
564
565 void
566 lock_profile_thread_exit(struct thread *td)
567 {
568 #ifdef INVARIANTS
569 struct lock_profile_object *l;
570
571 MPASS(curthread->td_critnest == 0);
572 #endif
573 /*
574 * If lock profiling was disabled we have to wait for reset to
575 * clear our pointers before we can exit safely.
576 */
577 lock_prof_reset_wait();
578 #ifdef INVARIANTS
579 LIST_FOREACH(l, &td->td_lprof[0], lpo_link)
580 printf("thread still holds lock acquired at %s:%d\n",
581 l->lpo_file, l->lpo_line);
582 LIST_FOREACH(l, &td->td_lprof[1], lpo_link)
583 printf("thread still holds lock acquired at %s:%d\n",
584 l->lpo_file, l->lpo_line);
585 #endif
586 MPASS(LIST_FIRST(&td->td_lprof[0]) == NULL);
587 MPASS(LIST_FIRST(&td->td_lprof[1]) == NULL);
588 }
589
590 void
591 lock_profile_release_lock(struct lock_object *lo)
592 {
593 struct lock_profile_object *l;
594 struct lock_prof_type *type;
595 struct lock_prof *lp;
596 uint64_t curtime, holdtime;
597 struct lpohead *head;
598 int spin;
599
600 if (SCHEDULER_STOPPED())
601 return;
602 if (lo->lo_flags & LO_NOPROFILE)
603 return;
604 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0;
605 head = &curthread->td_lprof[spin];
606 if (LIST_FIRST(head) == NULL)
607 return;
608 critical_enter();
609 /* Recheck enabled now that we're in a critical section. */
610 if (lock_prof_enable == 0 && lock_prof_resetting == 1)
611 goto out;
612 /*
613 * If lock profiling is not enabled we still want to remove the
614 * lpo from our queue.
615 */
616 LIST_FOREACH(l, head, lpo_link)
617 if (l->lpo_obj == lo)
618 break;
619 if (l == NULL)
620 goto out;
621 if (--l->lpo_ref > 0)
622 goto out;
623 lp = lock_profile_lookup(lo, spin, l->lpo_file, l->lpo_line);
624 if (lp == NULL)
625 goto release;
626 curtime = nanoseconds();
627 if (curtime < l->lpo_acqtime)
628 goto release;
629 holdtime = curtime - l->lpo_acqtime;
630
631 /*
632 * Record if the lock has been held longer now than ever
633 * before.
634 */
635 if (holdtime > lp->cnt_max)
636 lp->cnt_max = holdtime;
637 if (l->lpo_waittime > lp->cnt_wait_max)
638 lp->cnt_wait_max = l->lpo_waittime;
639 lp->cnt_tot += holdtime;
640 lp->cnt_wait += l->lpo_waittime;
641 lp->cnt_contest_locking += l->lpo_contest_locking;
642 lp->cnt_cur += l->lpo_cnt;
643 release:
644 LIST_REMOVE(l, lpo_link);
645 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin];
646 LIST_INSERT_HEAD(&type->lpt_lpoalloc, l, lpo_link);
647 out:
648 critical_exit();
649 }
650
651 static SYSCTL_NODE(_debug, OID_AUTO, lock, CTLFLAG_RD, NULL, "lock debugging");
652 static SYSCTL_NODE(_debug_lock, OID_AUTO, prof, CTLFLAG_RD, NULL,
653 "lock profiling");
654 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipspin, CTLFLAG_RW,
655 &lock_prof_skipspin, 0, "Skip profiling on spinlocks.");
656 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipcount, CTLFLAG_RW,
657 &lock_prof_skipcount, 0, "Sample approximately every N lock acquisitions.");
658 SYSCTL_INT(_debug_lock_prof, OID_AUTO, rejected, CTLFLAG_RD,
659 &lock_prof_rejected, 0, "Number of rejected profiling records");
660 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD,
661 NULL, 0, dump_lock_prof_stats, "A", "Lock profiling statistics");
662 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW,
663 NULL, 0, reset_lock_prof_stats, "I", "Reset lock profiling statistics");
664 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW,
665 NULL, 0, enable_lock_prof, "I", "Enable lock profiling");
666
667 #endif
Cache object: 3034064bb9e1e48b6360d11530ba371a
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