Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_lock.c
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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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