1/*- 2 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 */ 25 26/* 27 * This module holds the global variables and functions used to maintain 28 * lock_object structures. 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: stable/11/sys/kern/subr_lock.c 367457 2020-11-07 18:10:59Z dim $"); 33 34#include "opt_ddb.h" 35#include "opt_mprof.h" 36 37#include <sys/param.h> 38#include <sys/systm.h> 39#include <sys/kernel.h> 40#include <sys/ktr.h> 41#include <sys/lock.h> 42#include <sys/lock_profile.h> 43#include <sys/malloc.h> 44#include <sys/mutex.h> 45#include <sys/pcpu.h> 46#include <sys/proc.h> 47#include <sys/sbuf.h> 48#include <sys/sched.h> 49#include <sys/smp.h> 50#include <sys/sysctl.h> 51 52#ifdef DDB 53#include <ddb/ddb.h> 54#endif 55 56#include <machine/cpufunc.h> 57 58SDT_PROVIDER_DEFINE(lock); 59SDT_PROBE_DEFINE1(lock, , , starvation, "u_int"); 60 61CTASSERT(LOCK_CLASS_MAX == 15); 62 63struct lock_class *lock_classes[LOCK_CLASS_MAX + 1] = { 64 &lock_class_mtx_spin, 65 &lock_class_mtx_sleep, 66 &lock_class_sx, 67 &lock_class_rm, 68 &lock_class_rm_sleepable, 69 &lock_class_rw, 70 &lock_class_lockmgr, 71}; 72 73void 74lock_init(struct lock_object *lock, struct lock_class *class, const char *name, 75 const char *type, int flags) 76{ 77 int i; 78 79 /* Check for double-init and zero object. */ 80 KASSERT(flags & LO_NEW || !lock_initialized(lock), 81 ("lock \"%s\" %p already initialized", name, lock)); 82 83 /* Look up lock class to find its index. */ 84 for (i = 0; i < LOCK_CLASS_MAX; i++) 85 if (lock_classes[i] == class) { 86 lock->lo_flags = i << LO_CLASSSHIFT; 87 break; 88 } 89 KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class)); 90 91 /* Initialize the lock object. */ 92 lock->lo_name = name; 93 lock->lo_flags |= flags | LO_INITIALIZED; 94 LOCK_LOG_INIT(lock, 0); 95 WITNESS_INIT(lock, (type != NULL) ? type : name); 96} 97 98void 99lock_destroy(struct lock_object *lock) 100{ 101 102 KASSERT(lock_initialized(lock), ("lock %p is not initialized", lock)); 103 WITNESS_DESTROY(lock); 104 LOCK_LOG_DESTROY(lock, 0); 105 lock->lo_flags &= ~LO_INITIALIZED; 106} 107 108static SYSCTL_NODE(_debug, OID_AUTO, lock, CTLFLAG_RD, NULL, "lock debugging"); 109static SYSCTL_NODE(_debug_lock, OID_AUTO, delay, CTLFLAG_RD, NULL, 110 "lock delay"); 111 112static u_int __read_mostly starvation_limit = 131072; 113SYSCTL_INT(_debug_lock_delay, OID_AUTO, starvation_limit, CTLFLAG_RW, 114 &starvation_limit, 0, ""); 115 116static u_int __read_mostly restrict_starvation = 0; 117SYSCTL_INT(_debug_lock_delay, OID_AUTO, restrict_starvation, CTLFLAG_RW, 118 &restrict_starvation, 0, ""); 119 120void 121lock_delay(struct lock_delay_arg *la) 122{ 123 struct lock_delay_config *lc = la->config; 124 u_int i; 125 126 la->delay <<= 1; 127 if (__predict_false(la->delay > lc->max)) 128 la->delay = lc->max; 129 130 for (i = la->delay; i > 0; i--) 131 cpu_spinwait(); 132 133 la->spin_cnt += la->delay; 134 if (__predict_false(la->spin_cnt > starvation_limit)) { 135 SDT_PROBE1(lock, , , starvation, la->delay); 136 if (restrict_starvation) 137 la->delay = lc->base; 138 } 139} 140 141static u_int 142lock_roundup_2(u_int val) 143{ 144 u_int res; 145 146 for (res = 1; res <= val; res <<= 1) 147 continue; 148 149 return (res); 150} 151 152void 153lock_delay_default_init(struct lock_delay_config *lc) 154{ 155 156 lc->base = lock_roundup_2(mp_ncpus) / 4; 157 lc->max = lc->base * 1024; 158} 159 160#ifdef DDB 161DB_SHOW_COMMAND(lock, db_show_lock) 162{ 163 struct lock_object *lock; 164 struct lock_class *class; 165 166 if (!have_addr) 167 return; 168 lock = (struct lock_object *)addr; 169 if (LO_CLASSINDEX(lock) > LOCK_CLASS_MAX) { 170 db_printf("Unknown lock class: %d\n", LO_CLASSINDEX(lock)); 171 return; 172 } 173 class = LOCK_CLASS(lock); 174 db_printf(" class: %s\n", class->lc_name); 175 db_printf(" name: %s\n", lock->lo_name); 176 class->lc_ddb_show(lock); 177} 178#endif 179 180#ifdef LOCK_PROFILING 181 182/* 183 * One object per-thread for each lock the thread owns. Tracks individual 184 * lock instances. 185 */ 186struct lock_profile_object { 187 LIST_ENTRY(lock_profile_object) lpo_link; 188 struct lock_object *lpo_obj; 189 const char *lpo_file; 190 int lpo_line; 191 uint16_t lpo_ref; 192 uint16_t lpo_cnt; 193 uint64_t lpo_acqtime; 194 uint64_t lpo_waittime; 195 u_int lpo_contest_locking; 196}; 197 198/* 199 * One lock_prof for each (file, line, lock object) triple. 200 */ 201struct lock_prof { 202 SLIST_ENTRY(lock_prof) link; 203 struct lock_class *class; 204 const char *file; 205 const char *name; 206 int line; 207 int ticks; 208 uintmax_t cnt_wait_max; 209 uintmax_t cnt_max; 210 uintmax_t cnt_tot; 211 uintmax_t cnt_wait; 212 uintmax_t cnt_cur; 213 uintmax_t cnt_contest_locking; 214}; 215 216SLIST_HEAD(lphead, lock_prof); 217 218#define LPROF_HASH_SIZE 4096 219#define LPROF_HASH_MASK (LPROF_HASH_SIZE - 1) 220#define LPROF_CACHE_SIZE 4096 221 222/* 223 * Array of objects and profs for each type of object for each cpu. Spinlocks 224 * are handled separately because a thread may be preempted and acquire a 225 * spinlock while in the lock profiling code of a non-spinlock. In this way 226 * we only need a critical section to protect the per-cpu lists. 227 */ 228struct lock_prof_type { 229 struct lphead lpt_lpalloc; 230 struct lpohead lpt_lpoalloc; 231 struct lphead lpt_hash[LPROF_HASH_SIZE]; 232 struct lock_prof lpt_prof[LPROF_CACHE_SIZE]; 233 struct lock_profile_object lpt_objs[LPROF_CACHE_SIZE]; 234}; 235 236struct lock_prof_cpu { 237 struct lock_prof_type lpc_types[2]; /* One for spin one for other. */ 238}; 239 240struct lock_prof_cpu *lp_cpu[MAXCPU]; 241 242volatile int __read_mostly lock_prof_enable; 243static volatile int lock_prof_resetting; 244 245#define LPROF_SBUF_SIZE 256 246 247static int lock_prof_rejected; 248static int lock_prof_skipspin; 249static int lock_prof_skipcount; 250 251#ifndef USE_CPU_NANOSECONDS 252uint64_t 253nanoseconds(void) 254{ 255 struct bintime bt; 256 uint64_t ns; 257 258 binuptime(&bt); 259 /* From bintime2timespec */ 260 ns = bt.sec * (uint64_t)1000000000; 261 ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32; 262 return (ns); 263} 264#endif 265 266static void 267lock_prof_init_type(struct lock_prof_type *type) 268{ 269 int i; 270 271 SLIST_INIT(&type->lpt_lpalloc); 272 LIST_INIT(&type->lpt_lpoalloc); 273 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 274 SLIST_INSERT_HEAD(&type->lpt_lpalloc, &type->lpt_prof[i], 275 link); 276 LIST_INSERT_HEAD(&type->lpt_lpoalloc, &type->lpt_objs[i], 277 lpo_link); 278 } 279} 280 281static void 282lock_prof_init(void *arg) 283{ 284 int cpu; 285 286 for (cpu = 0; cpu <= mp_maxid; cpu++) { 287 lp_cpu[cpu] = malloc(sizeof(*lp_cpu[cpu]), M_DEVBUF, 288 M_WAITOK | M_ZERO); 289 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[0]); 290 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[1]); 291 } 292} 293SYSINIT(lockprof, SI_SUB_SMP, SI_ORDER_ANY, lock_prof_init, NULL); 294 295static void 296lock_prof_reset_wait(void) 297{ 298 299 /* 300 * Spin relinquishing our cpu so that quiesce_all_cpus may 301 * complete. 302 */ 303 while (lock_prof_resetting) 304 sched_relinquish(curthread); 305} 306 307static void 308lock_prof_reset(void) 309{ 310 struct lock_prof_cpu *lpc; 311 int enabled, i, cpu; 312 313 /* 314 * We not only race with acquiring and releasing locks but also 315 * thread exit. To be certain that threads exit without valid head 316 * pointers they must see resetting set before enabled is cleared. 317 * Otherwise a lock may not be removed from a per-thread list due 318 * to disabled being set but not wait for reset() to remove it below. 319 */ 320 atomic_store_rel_int(&lock_prof_resetting, 1); 321 enabled = lock_prof_enable; 322 lock_prof_enable = 0; 323 quiesce_all_cpus("profreset", 0); 324 /* 325 * Some objects may have migrated between CPUs. Clear all links 326 * before we zero the structures. Some items may still be linked 327 * into per-thread lists as well. 328 */ 329 for (cpu = 0; cpu <= mp_maxid; cpu++) { 330 lpc = lp_cpu[cpu]; 331 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 332 LIST_REMOVE(&lpc->lpc_types[0].lpt_objs[i], lpo_link); 333 LIST_REMOVE(&lpc->lpc_types[1].lpt_objs[i], lpo_link); 334 } 335 } 336 for (cpu = 0; cpu <= mp_maxid; cpu++) { 337 lpc = lp_cpu[cpu]; 338 bzero(lpc, sizeof(*lpc)); 339 lock_prof_init_type(&lpc->lpc_types[0]); 340 lock_prof_init_type(&lpc->lpc_types[1]); 341 } 342 atomic_store_rel_int(&lock_prof_resetting, 0); 343 lock_prof_enable = enabled; 344} 345 346static void 347lock_prof_output(struct lock_prof *lp, struct sbuf *sb) 348{ 349 const char *p; 350 351 for (p = lp->file; p != NULL && strncmp(p, "../", 3) == 0; p += 3); 352 sbuf_printf(sb, 353 "%8ju %9ju %11ju %11ju %11ju %6ju %6ju %2ju %6ju %s:%d (%s:%s)\n", 354 lp->cnt_max / 1000, lp->cnt_wait_max / 1000, lp->cnt_tot / 1000, 355 lp->cnt_wait / 1000, lp->cnt_cur, 356 lp->cnt_cur == 0 ? (uintmax_t)0 : 357 lp->cnt_tot / (lp->cnt_cur * 1000), 358 lp->cnt_cur == 0 ? (uintmax_t)0 : 359 lp->cnt_wait / (lp->cnt_cur * 1000), 360 (uintmax_t)0, lp->cnt_contest_locking, 361 p, lp->line, lp->class->lc_name, lp->name); 362} 363 364static void 365lock_prof_sum(struct lock_prof *match, struct lock_prof *dst, int hash, 366 int spin, int t) 367{ 368 struct lock_prof_type *type; 369 struct lock_prof *l; 370 int cpu; 371 372 dst->file = match->file; 373 dst->line = match->line; 374 dst->class = match->class; 375 dst->name = match->name; 376 377 for (cpu = 0; cpu <= mp_maxid; cpu++) { 378 if (lp_cpu[cpu] == NULL) 379 continue; 380 type = &lp_cpu[cpu]->lpc_types[spin]; 381 SLIST_FOREACH(l, &type->lpt_hash[hash], link) { 382 if (l->ticks == t) 383 continue; 384 if (l->file != match->file || l->line != match->line || 385 l->name != match->name) 386 continue; 387 l->ticks = t; 388 if (l->cnt_max > dst->cnt_max) 389 dst->cnt_max = l->cnt_max; 390 if (l->cnt_wait_max > dst->cnt_wait_max) 391 dst->cnt_wait_max = l->cnt_wait_max; 392 dst->cnt_tot += l->cnt_tot; 393 dst->cnt_wait += l->cnt_wait; 394 dst->cnt_cur += l->cnt_cur; 395 dst->cnt_contest_locking += l->cnt_contest_locking; 396 } 397 } 398 399} 400 401static void 402lock_prof_type_stats(struct lock_prof_type *type, struct sbuf *sb, int spin, 403 int t) 404{ 405 struct lock_prof *l; 406 int i; 407 408 for (i = 0; i < LPROF_HASH_SIZE; ++i) { 409 SLIST_FOREACH(l, &type->lpt_hash[i], link) { 410 struct lock_prof lp = {}; 411 412 if (l->ticks == t) 413 continue; 414 lock_prof_sum(l, &lp, i, spin, t); 415 lock_prof_output(&lp, sb); 416 } 417 } 418} 419 420static int 421dump_lock_prof_stats(SYSCTL_HANDLER_ARGS) 422{ 423 struct sbuf *sb; 424 int error, cpu, t; 425 int enabled; 426 427 error = sysctl_wire_old_buffer(req, 0); 428 if (error != 0) 429 return (error); 430 sb = sbuf_new_for_sysctl(NULL, NULL, LPROF_SBUF_SIZE, req); 431 sbuf_printf(sb, "\n%8s %9s %11s %11s %11s %6s %6s %2s %6s %s\n", 432 "max", "wait_max", "total", "wait_total", "count", "avg", "wait_avg", "cnt_hold", "cnt_lock", "name"); 433 enabled = lock_prof_enable; 434 lock_prof_enable = 0; 435 quiesce_all_cpus("profstat", 0); 436 t = ticks; 437 for (cpu = 0; cpu <= mp_maxid; cpu++) { 438 if (lp_cpu[cpu] == NULL) 439 continue; 440 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[0], sb, 0, t); 441 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[1], sb, 1, t); 442 } 443 lock_prof_enable = enabled; 444 445 error = sbuf_finish(sb); 446 /* Output a trailing NUL. */ 447 if (error == 0) 448 error = SYSCTL_OUT(req, "", 1); 449 sbuf_delete(sb); 450 return (error); 451} 452 453static int 454enable_lock_prof(SYSCTL_HANDLER_ARGS) 455{ 456 int error, v; 457 458 v = lock_prof_enable; 459 error = sysctl_handle_int(oidp, &v, v, req); 460 if (error) 461 return (error); 462 if (req->newptr == NULL) 463 return (error); 464 if (v == lock_prof_enable) 465 return (0); 466 if (v == 1) 467 lock_prof_reset(); 468 lock_prof_enable = !!v; 469 470 return (0); 471} 472 473static int 474reset_lock_prof_stats(SYSCTL_HANDLER_ARGS) 475{ 476 int error, v; 477 478 v = 0; 479 error = sysctl_handle_int(oidp, &v, 0, req); 480 if (error) 481 return (error); 482 if (req->newptr == NULL) 483 return (error); 484 if (v == 0) 485 return (0); 486 lock_prof_reset(); 487 488 return (0); 489} 490 491static struct lock_prof * 492lock_profile_lookup(struct lock_object *lo, int spin, const char *file, 493 int line) 494{ 495 const char *unknown = "(unknown)"; 496 struct lock_prof_type *type; 497 struct lock_prof *lp; 498 struct lphead *head; 499 const char *p; 500 u_int hash; 501 502 p = file; 503 if (p == NULL || *p == '\0') 504 p = unknown; 505 hash = (uintptr_t)lo->lo_name * 31 + (uintptr_t)p * 31 + line; 506 hash &= LPROF_HASH_MASK; 507 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 508 head = &type->lpt_hash[hash]; 509 SLIST_FOREACH(lp, head, link) { 510 if (lp->line == line && lp->file == p && 511 lp->name == lo->lo_name) 512 return (lp); 513 514 } 515 lp = SLIST_FIRST(&type->lpt_lpalloc); 516 if (lp == NULL) { 517 lock_prof_rejected++; 518 return (lp); 519 } 520 SLIST_REMOVE_HEAD(&type->lpt_lpalloc, link); 521 lp->file = p; 522 lp->line = line; 523 lp->class = LOCK_CLASS(lo); 524 lp->name = lo->lo_name; 525 SLIST_INSERT_HEAD(&type->lpt_hash[hash], lp, link); 526 return (lp); 527} 528 529static struct lock_profile_object * 530lock_profile_object_lookup(struct lock_object *lo, int spin, const char *file, 531 int line) 532{ 533 struct lock_profile_object *l; 534 struct lock_prof_type *type; 535 struct lpohead *head; 536 537 head = &curthread->td_lprof[spin]; 538 LIST_FOREACH(l, head, lpo_link) 539 if (l->lpo_obj == lo && l->lpo_file == file && 540 l->lpo_line == line) 541 return (l); 542 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 543 l = LIST_FIRST(&type->lpt_lpoalloc); 544 if (l == NULL) { 545 lock_prof_rejected++; 546 return (NULL); 547 } 548 LIST_REMOVE(l, lpo_link); 549 l->lpo_obj = lo; 550 l->lpo_file = file; 551 l->lpo_line = line; 552 l->lpo_cnt = 0; 553 LIST_INSERT_HEAD(head, l, lpo_link); 554 555 return (l); 556} 557 558void 559lock_profile_obtain_lock_success(struct lock_object *lo, int contested, 560 uint64_t waittime, const char *file, int line) 561{ 562 static int lock_prof_count; 563 struct lock_profile_object *l; 564 int spin; 565 566 if (SCHEDULER_STOPPED()) 567 return; 568 569 /* don't reset the timer when/if recursing */ 570 if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE)) 571 return; 572 if (lock_prof_skipcount && 573 (++lock_prof_count % lock_prof_skipcount) != 0) 574 return; 575 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 576 if (spin && lock_prof_skipspin == 1) 577 return; 578 critical_enter(); 579 /* Recheck enabled now that we're in a critical section. */ 580 if (lock_prof_enable == 0) 581 goto out; 582 l = lock_profile_object_lookup(lo, spin, file, line); 583 if (l == NULL) 584 goto out; 585 l->lpo_cnt++; 586 if (++l->lpo_ref > 1) 587 goto out; 588 l->lpo_contest_locking = contested; 589 l->lpo_acqtime = nanoseconds(); 590 if (waittime && (l->lpo_acqtime > waittime)) 591 l->lpo_waittime = l->lpo_acqtime - waittime; 592 else 593 l->lpo_waittime = 0; 594out: 595 critical_exit(); 596} 597 598void 599lock_profile_thread_exit(struct thread *td) 600{ 601#ifdef INVARIANTS 602 struct lock_profile_object *l; 603 604 MPASS(curthread->td_critnest == 0); 605#endif 606 /* 607 * If lock profiling was disabled we have to wait for reset to 608 * clear our pointers before we can exit safely. 609 */ 610 lock_prof_reset_wait(); 611#ifdef INVARIANTS 612 LIST_FOREACH(l, &td->td_lprof[0], lpo_link) 613 printf("thread still holds lock acquired at %s:%d\n", 614 l->lpo_file, l->lpo_line); 615 LIST_FOREACH(l, &td->td_lprof[1], lpo_link) 616 printf("thread still holds lock acquired at %s:%d\n", 617 l->lpo_file, l->lpo_line); 618#endif 619 MPASS(LIST_FIRST(&td->td_lprof[0]) == NULL); 620 MPASS(LIST_FIRST(&td->td_lprof[1]) == NULL); 621} 622 623void 624lock_profile_release_lock(struct lock_object *lo) 625{ 626 struct lock_profile_object *l; 627 struct lock_prof_type *type; 628 struct lock_prof *lp; 629 uint64_t curtime, holdtime; 630 struct lpohead *head; 631 int spin; 632 633 if (SCHEDULER_STOPPED()) 634 return; 635 if (lo->lo_flags & LO_NOPROFILE) 636 return; 637 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 638 head = &curthread->td_lprof[spin]; 639 if (LIST_FIRST(head) == NULL) 640 return; 641 critical_enter(); 642 /* Recheck enabled now that we're in a critical section. */ 643 if (lock_prof_enable == 0 && lock_prof_resetting == 1) 644 goto out; 645 /* 646 * If lock profiling is not enabled we still want to remove the 647 * lpo from our queue. 648 */ 649 LIST_FOREACH(l, head, lpo_link) 650 if (l->lpo_obj == lo) 651 break; 652 if (l == NULL) 653 goto out; 654 if (--l->lpo_ref > 0) 655 goto out; 656 lp = lock_profile_lookup(lo, spin, l->lpo_file, l->lpo_line); 657 if (lp == NULL) 658 goto release; 659 curtime = nanoseconds(); 660 if (curtime < l->lpo_acqtime) 661 goto release; 662 holdtime = curtime - l->lpo_acqtime; 663 664 /* 665 * Record if the lock has been held longer now than ever 666 * before. 667 */ 668 if (holdtime > lp->cnt_max) 669 lp->cnt_max = holdtime; 670 if (l->lpo_waittime > lp->cnt_wait_max) 671 lp->cnt_wait_max = l->lpo_waittime; 672 lp->cnt_tot += holdtime; 673 lp->cnt_wait += l->lpo_waittime; 674 lp->cnt_contest_locking += l->lpo_contest_locking; 675 lp->cnt_cur += l->lpo_cnt; 676release: 677 LIST_REMOVE(l, lpo_link); 678 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 679 LIST_INSERT_HEAD(&type->lpt_lpoalloc, l, lpo_link); 680out: 681 critical_exit(); 682} 683 684static SYSCTL_NODE(_debug_lock, OID_AUTO, prof, CTLFLAG_RD, NULL, 685 "lock profiling"); 686SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipspin, CTLFLAG_RW, 687 &lock_prof_skipspin, 0, "Skip profiling on spinlocks."); 688SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipcount, CTLFLAG_RW, 689 &lock_prof_skipcount, 0, "Sample approximately every N lock acquisitions."); 690SYSCTL_INT(_debug_lock_prof, OID_AUTO, rejected, CTLFLAG_RD, 691 &lock_prof_rejected, 0, "Number of rejected profiling records"); 692SYSCTL_PROC(_debug_lock_prof, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 693 NULL, 0, dump_lock_prof_stats, "A", "Lock profiling statistics"); 694SYSCTL_PROC(_debug_lock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 695 NULL, 0, reset_lock_prof_stats, "I", "Reset lock profiling statistics"); 696SYSCTL_PROC(_debug_lock_prof, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 697 NULL, 0, enable_lock_prof, "I", "Enable lock profiling"); 698 699#endif 700