1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * This module holds the global variables and functions used to maintain 30 * lock_object structures. 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "opt_ddb.h" 37 #include "opt_mprof.h" 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/kernel.h> 42 #include <sys/ktr.h> 43 #include <sys/lock.h> 44 #include <sys/lock_profile.h> 45 #include <sys/malloc.h> 46 #include <sys/mutex.h> 47 #include <sys/pcpu.h> 48 #include <sys/proc.h> 49 #include <sys/sbuf.h> 50 #include <sys/sched.h> 51 #include <sys/smp.h> 52 #include <sys/sysctl.h> 53 54 #ifdef DDB 55 #include <ddb/ddb.h> 56 #endif 57 58 #include <machine/cpufunc.h> 59 60 SDT_PROVIDER_DEFINE(lock); 61 SDT_PROBE_DEFINE1(lock, , , starvation, "u_int"); 62 63 CTASSERT(LOCK_CLASS_MAX == 15); 64 65 struct lock_class *lock_classes[LOCK_CLASS_MAX + 1] = { 66 &lock_class_mtx_spin, 67 &lock_class_mtx_sleep, 68 &lock_class_sx, 69 &lock_class_rm, 70 &lock_class_rm_sleepable, 71 &lock_class_rw, 72 &lock_class_lockmgr, 73 }; 74 75 void 76 lock_init(struct lock_object *lock, struct lock_class *class, const char *name, 77 const char *type, int flags) 78 { 79 int i; 80 81 /* Check for double-init and zero object. */ 82 KASSERT(flags & LO_NEW || !lock_initialized(lock), 83 ("lock \"%s\" %p already initialized", name, lock)); 84 85 /* Look up lock class to find its index. */ 86 for (i = 0; i < LOCK_CLASS_MAX; i++) 87 if (lock_classes[i] == class) { 88 lock->lo_flags = i << LO_CLASSSHIFT; 89 break; 90 } 91 KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class)); 92 93 /* Initialize the lock object. */ 94 lock->lo_name = name; 95 lock->lo_flags |= flags | LO_INITIALIZED; 96 LOCK_LOG_INIT(lock, 0); 97 WITNESS_INIT(lock, (type != NULL) ? type : name); 98 } 99 100 void 101 lock_destroy(struct lock_object *lock) 102 { 103 104 KASSERT(lock_initialized(lock), ("lock %p is not initialized", lock)); 105 WITNESS_DESTROY(lock); 106 LOCK_LOG_DESTROY(lock, 0); 107 lock->lo_flags &= ~LO_INITIALIZED; 108 } 109 110 static SYSCTL_NODE(_debug, OID_AUTO, lock, CTLFLAG_RD, NULL, "lock debugging"); 111 static SYSCTL_NODE(_debug_lock, OID_AUTO, delay, CTLFLAG_RD, NULL, 112 "lock delay"); 113 114 static u_int __read_mostly starvation_limit = 131072; 115 SYSCTL_INT(_debug_lock_delay, OID_AUTO, starvation_limit, CTLFLAG_RW, 116 &starvation_limit, 0, ""); 117 118 static u_int __read_mostly restrict_starvation = 0; 119 SYSCTL_INT(_debug_lock_delay, OID_AUTO, restrict_starvation, CTLFLAG_RW, 120 &restrict_starvation, 0, ""); 121 122 void 123 lock_delay(struct lock_delay_arg *la) 124 { 125 struct lock_delay_config *lc = la->config; 126 u_int i; 127 128 la->delay <<= 1; 129 if (__predict_false(la->delay > lc->max)) 130 la->delay = lc->max; 131 132 for (i = la->delay; i > 0; i--) 133 cpu_spinwait(); 134 135 la->spin_cnt += la->delay; 136 if (__predict_false(la->spin_cnt > starvation_limit)) { 137 SDT_PROBE1(lock, , , starvation, la->delay); 138 if (restrict_starvation) 139 la->delay = lc->base; 140 } 141 } 142 143 static u_int 144 lock_roundup_2(u_int val) 145 { 146 u_int res; 147 148 for (res = 1; res <= val; res <<= 1) 149 continue; 150 151 return (res); 152 } 153 154 void 155 lock_delay_default_init(struct lock_delay_config *lc) 156 { 157 158 lc->base = 1; 159 lc->max = lock_roundup_2(mp_ncpus) * 256; 160 if (lc->max > 32678) 161 lc->max = 32678; 162 } 163 164 #ifdef DDB 165 DB_SHOW_COMMAND(lock, db_show_lock) 166 { 167 struct lock_object *lock; 168 struct lock_class *class; 169 170 if (!have_addr) 171 return; 172 lock = (struct lock_object *)addr; 173 if (LO_CLASSINDEX(lock) > LOCK_CLASS_MAX) { 174 db_printf("Unknown lock class: %d\n", LO_CLASSINDEX(lock)); 175 return; 176 } 177 class = LOCK_CLASS(lock); 178 db_printf(" class: %s\n", class->lc_name); 179 db_printf(" name: %s\n", lock->lo_name); 180 class->lc_ddb_show(lock); 181 } 182 #endif 183 184 #ifdef LOCK_PROFILING 185 186 /* 187 * One object per-thread for each lock the thread owns. Tracks individual 188 * lock instances. 189 */ 190 struct lock_profile_object { 191 LIST_ENTRY(lock_profile_object) lpo_link; 192 struct lock_object *lpo_obj; 193 const char *lpo_file; 194 int lpo_line; 195 uint16_t lpo_ref; 196 uint16_t lpo_cnt; 197 uint64_t lpo_acqtime; 198 uint64_t lpo_waittime; 199 u_int lpo_contest_locking; 200 }; 201 202 /* 203 * One lock_prof for each (file, line, lock object) triple. 204 */ 205 struct lock_prof { 206 SLIST_ENTRY(lock_prof) link; 207 struct lock_class *class; 208 const char *file; 209 const char *name; 210 int line; 211 int ticks; 212 uintmax_t cnt_wait_max; 213 uintmax_t cnt_max; 214 uintmax_t cnt_tot; 215 uintmax_t cnt_wait; 216 uintmax_t cnt_cur; 217 uintmax_t cnt_contest_locking; 218 }; 219 220 SLIST_HEAD(lphead, lock_prof); 221 222 #define LPROF_HASH_SIZE 4096 223 #define LPROF_HASH_MASK (LPROF_HASH_SIZE - 1) 224 #define LPROF_CACHE_SIZE 4096 225 226 /* 227 * Array of objects and profs for each type of object for each cpu. Spinlocks 228 * are handled separately because a thread may be preempted and acquire a 229 * spinlock while in the lock profiling code of a non-spinlock. In this way 230 * we only need a critical section to protect the per-cpu lists. 231 */ 232 struct lock_prof_type { 233 struct lphead lpt_lpalloc; 234 struct lpohead lpt_lpoalloc; 235 struct lphead lpt_hash[LPROF_HASH_SIZE]; 236 struct lock_prof lpt_prof[LPROF_CACHE_SIZE]; 237 struct lock_profile_object lpt_objs[LPROF_CACHE_SIZE]; 238 }; 239 240 struct lock_prof_cpu { 241 struct lock_prof_type lpc_types[2]; /* One for spin one for other. */ 242 }; 243 244 struct lock_prof_cpu *lp_cpu[MAXCPU]; 245 246 volatile int __read_mostly lock_prof_enable; 247 static volatile int lock_prof_resetting; 248 249 #define LPROF_SBUF_SIZE 256 250 251 static int lock_prof_rejected; 252 static int lock_prof_skipspin; 253 static int lock_prof_skipcount; 254 255 #ifndef USE_CPU_NANOSECONDS 256 uint64_t 257 nanoseconds(void) 258 { 259 struct bintime bt; 260 uint64_t ns; 261 262 binuptime(&bt); 263 /* From bintime2timespec */ 264 ns = bt.sec * (uint64_t)1000000000; 265 ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32; 266 return (ns); 267 } 268 #endif 269 270 static void 271 lock_prof_init_type(struct lock_prof_type *type) 272 { 273 int i; 274 275 SLIST_INIT(&type->lpt_lpalloc); 276 LIST_INIT(&type->lpt_lpoalloc); 277 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 278 SLIST_INSERT_HEAD(&type->lpt_lpalloc, &type->lpt_prof[i], 279 link); 280 LIST_INSERT_HEAD(&type->lpt_lpoalloc, &type->lpt_objs[i], 281 lpo_link); 282 } 283 } 284 285 static void 286 lock_prof_init(void *arg) 287 { 288 int cpu; 289 290 for (cpu = 0; cpu <= mp_maxid; cpu++) { 291 lp_cpu[cpu] = malloc(sizeof(*lp_cpu[cpu]), M_DEVBUF, 292 M_WAITOK | M_ZERO); 293 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[0]); 294 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[1]); 295 } 296 } 297 SYSINIT(lockprof, SI_SUB_SMP, SI_ORDER_ANY, lock_prof_init, NULL); 298 299 static void 300 lock_prof_reset_wait(void) 301 { 302 303 /* 304 * Spin relinquishing our cpu so that quiesce_all_cpus may 305 * complete. 306 */ 307 while (lock_prof_resetting) 308 sched_relinquish(curthread); 309 } 310 311 static void 312 lock_prof_reset(void) 313 { 314 struct lock_prof_cpu *lpc; 315 int enabled, i, cpu; 316 317 /* 318 * We not only race with acquiring and releasing locks but also 319 * thread exit. To be certain that threads exit without valid head 320 * pointers they must see resetting set before enabled is cleared. 321 * Otherwise a lock may not be removed from a per-thread list due 322 * to disabled being set but not wait for reset() to remove it below. 323 */ 324 atomic_store_rel_int(&lock_prof_resetting, 1); 325 enabled = lock_prof_enable; 326 lock_prof_enable = 0; 327 quiesce_all_cpus("profreset", 0); 328 /* 329 * Some objects may have migrated between CPUs. Clear all links 330 * before we zero the structures. Some items may still be linked 331 * into per-thread lists as well. 332 */ 333 for (cpu = 0; cpu <= mp_maxid; cpu++) { 334 lpc = lp_cpu[cpu]; 335 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 336 LIST_REMOVE(&lpc->lpc_types[0].lpt_objs[i], lpo_link); 337 LIST_REMOVE(&lpc->lpc_types[1].lpt_objs[i], lpo_link); 338 } 339 } 340 for (cpu = 0; cpu <= mp_maxid; cpu++) { 341 lpc = lp_cpu[cpu]; 342 bzero(lpc, sizeof(*lpc)); 343 lock_prof_init_type(&lpc->lpc_types[0]); 344 lock_prof_init_type(&lpc->lpc_types[1]); 345 } 346 atomic_store_rel_int(&lock_prof_resetting, 0); 347 lock_prof_enable = enabled; 348 } 349 350 static void 351 lock_prof_output(struct lock_prof *lp, struct sbuf *sb) 352 { 353 const char *p; 354 355 for (p = lp->file; p != NULL && strncmp(p, "../", 3) == 0; p += 3); 356 sbuf_printf(sb, 357 "%8ju %9ju %11ju %11ju %11ju %6ju %6ju %2ju %6ju %s:%d (%s:%s)\n", 358 lp->cnt_max / 1000, lp->cnt_wait_max / 1000, lp->cnt_tot / 1000, 359 lp->cnt_wait / 1000, lp->cnt_cur, 360 lp->cnt_cur == 0 ? (uintmax_t)0 : 361 lp->cnt_tot / (lp->cnt_cur * 1000), 362 lp->cnt_cur == 0 ? (uintmax_t)0 : 363 lp->cnt_wait / (lp->cnt_cur * 1000), 364 (uintmax_t)0, lp->cnt_contest_locking, 365 p, lp->line, lp->class->lc_name, lp->name); 366 } 367 368 static void 369 lock_prof_sum(struct lock_prof *match, struct lock_prof *dst, int hash, 370 int spin, int t) 371 { 372 struct lock_prof_type *type; 373 struct lock_prof *l; 374 int cpu; 375 376 dst->file = match->file; 377 dst->line = match->line; 378 dst->class = match->class; 379 dst->name = match->name; 380 381 for (cpu = 0; cpu <= mp_maxid; cpu++) { 382 if (lp_cpu[cpu] == NULL) 383 continue; 384 type = &lp_cpu[cpu]->lpc_types[spin]; 385 SLIST_FOREACH(l, &type->lpt_hash[hash], link) { 386 if (l->ticks == t) 387 continue; 388 if (l->file != match->file || l->line != match->line || 389 l->name != match->name) 390 continue; 391 l->ticks = t; 392 if (l->cnt_max > dst->cnt_max) 393 dst->cnt_max = l->cnt_max; 394 if (l->cnt_wait_max > dst->cnt_wait_max) 395 dst->cnt_wait_max = l->cnt_wait_max; 396 dst->cnt_tot += l->cnt_tot; 397 dst->cnt_wait += l->cnt_wait; 398 dst->cnt_cur += l->cnt_cur; 399 dst->cnt_contest_locking += l->cnt_contest_locking; 400 } 401 } 402 403 } 404 405 static void 406 lock_prof_type_stats(struct lock_prof_type *type, struct sbuf *sb, int spin, 407 int t) 408 { 409 struct lock_prof *l; 410 int i; 411 412 for (i = 0; i < LPROF_HASH_SIZE; ++i) { 413 SLIST_FOREACH(l, &type->lpt_hash[i], link) { 414 struct lock_prof lp = {}; 415 416 if (l->ticks == t) 417 continue; 418 lock_prof_sum(l, &lp, i, spin, t); 419 lock_prof_output(&lp, sb); 420 } 421 } 422 } 423 424 static int 425 dump_lock_prof_stats(SYSCTL_HANDLER_ARGS) 426 { 427 struct sbuf *sb; 428 int error, cpu, t; 429 int enabled; 430 431 error = sysctl_wire_old_buffer(req, 0); 432 if (error != 0) 433 return (error); 434 sb = sbuf_new_for_sysctl(NULL, NULL, LPROF_SBUF_SIZE, req); 435 sbuf_printf(sb, "\n%8s %9s %11s %11s %11s %6s %6s %2s %6s %s\n", 436 "max", "wait_max", "total", "wait_total", "count", "avg", "wait_avg", "cnt_hold", "cnt_lock", "name"); 437 enabled = lock_prof_enable; 438 lock_prof_enable = 0; 439 quiesce_all_cpus("profstat", 0); 440 t = ticks; 441 for (cpu = 0; cpu <= mp_maxid; cpu++) { 442 if (lp_cpu[cpu] == NULL) 443 continue; 444 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[0], sb, 0, t); 445 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[1], sb, 1, t); 446 } 447 lock_prof_enable = enabled; 448 449 error = sbuf_finish(sb); 450 /* Output a trailing NUL. */ 451 if (error == 0) 452 error = SYSCTL_OUT(req, "", 1); 453 sbuf_delete(sb); 454 return (error); 455 } 456 457 static int 458 enable_lock_prof(SYSCTL_HANDLER_ARGS) 459 { 460 int error, v; 461 462 v = lock_prof_enable; 463 error = sysctl_handle_int(oidp, &v, v, req); 464 if (error) 465 return (error); 466 if (req->newptr == NULL) 467 return (error); 468 if (v == lock_prof_enable) 469 return (0); 470 if (v == 1) 471 lock_prof_reset(); 472 lock_prof_enable = !!v; 473 474 return (0); 475 } 476 477 static int 478 reset_lock_prof_stats(SYSCTL_HANDLER_ARGS) 479 { 480 int error, v; 481 482 v = 0; 483 error = sysctl_handle_int(oidp, &v, 0, req); 484 if (error) 485 return (error); 486 if (req->newptr == NULL) 487 return (error); 488 if (v == 0) 489 return (0); 490 lock_prof_reset(); 491 492 return (0); 493 } 494 495 static struct lock_prof * 496 lock_profile_lookup(struct lock_object *lo, int spin, const char *file, 497 int line) 498 { 499 const char *unknown = "(unknown)"; 500 struct lock_prof_type *type; 501 struct lock_prof *lp; 502 struct lphead *head; 503 const char *p; 504 u_int hash; 505 506 p = file; 507 if (p == NULL || *p == '\0') 508 p = unknown; 509 hash = (uintptr_t)lo->lo_name * 31 + (uintptr_t)p * 31 + line; 510 hash &= LPROF_HASH_MASK; 511 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 512 head = &type->lpt_hash[hash]; 513 SLIST_FOREACH(lp, head, link) { 514 if (lp->line == line && lp->file == p && 515 lp->name == lo->lo_name) 516 return (lp); 517 518 } 519 lp = SLIST_FIRST(&type->lpt_lpalloc); 520 if (lp == NULL) { 521 lock_prof_rejected++; 522 return (lp); 523 } 524 SLIST_REMOVE_HEAD(&type->lpt_lpalloc, link); 525 lp->file = p; 526 lp->line = line; 527 lp->class = LOCK_CLASS(lo); 528 lp->name = lo->lo_name; 529 SLIST_INSERT_HEAD(&type->lpt_hash[hash], lp, link); 530 return (lp); 531 } 532 533 static struct lock_profile_object * 534 lock_profile_object_lookup(struct lock_object *lo, int spin, const char *file, 535 int line) 536 { 537 struct lock_profile_object *l; 538 struct lock_prof_type *type; 539 struct lpohead *head; 540 541 head = &curthread->td_lprof[spin]; 542 LIST_FOREACH(l, head, lpo_link) 543 if (l->lpo_obj == lo && l->lpo_file == file && 544 l->lpo_line == line) 545 return (l); 546 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 547 l = LIST_FIRST(&type->lpt_lpoalloc); 548 if (l == NULL) { 549 lock_prof_rejected++; 550 return (NULL); 551 } 552 LIST_REMOVE(l, lpo_link); 553 l->lpo_obj = lo; 554 l->lpo_file = file; 555 l->lpo_line = line; 556 l->lpo_cnt = 0; 557 LIST_INSERT_HEAD(head, l, lpo_link); 558 559 return (l); 560 } 561 562 void 563 lock_profile_obtain_lock_success(struct lock_object *lo, int contested, 564 uint64_t waittime, const char *file, int line) 565 { 566 static int lock_prof_count; 567 struct lock_profile_object *l; 568 int spin; 569 570 if (SCHEDULER_STOPPED()) 571 return; 572 573 /* don't reset the timer when/if recursing */ 574 if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE)) 575 return; 576 if (lock_prof_skipcount && 577 (++lock_prof_count % lock_prof_skipcount) != 0) 578 return; 579 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 580 if (spin && lock_prof_skipspin == 1) 581 return; 582 critical_enter(); 583 /* Recheck enabled now that we're in a critical section. */ 584 if (lock_prof_enable == 0) 585 goto out; 586 l = lock_profile_object_lookup(lo, spin, file, line); 587 if (l == NULL) 588 goto out; 589 l->lpo_cnt++; 590 if (++l->lpo_ref > 1) 591 goto out; 592 l->lpo_contest_locking = contested; 593 l->lpo_acqtime = nanoseconds(); 594 if (waittime && (l->lpo_acqtime > waittime)) 595 l->lpo_waittime = l->lpo_acqtime - waittime; 596 else 597 l->lpo_waittime = 0; 598 out: 599 critical_exit(); 600 } 601 602 void 603 lock_profile_thread_exit(struct thread *td) 604 { 605 #ifdef INVARIANTS 606 struct lock_profile_object *l; 607 608 MPASS(curthread->td_critnest == 0); 609 #endif 610 /* 611 * If lock profiling was disabled we have to wait for reset to 612 * clear our pointers before we can exit safely. 613 */ 614 lock_prof_reset_wait(); 615 #ifdef INVARIANTS 616 LIST_FOREACH(l, &td->td_lprof[0], lpo_link) 617 printf("thread still holds lock acquired at %s:%d\n", 618 l->lpo_file, l->lpo_line); 619 LIST_FOREACH(l, &td->td_lprof[1], lpo_link) 620 printf("thread still holds lock acquired at %s:%d\n", 621 l->lpo_file, l->lpo_line); 622 #endif 623 MPASS(LIST_FIRST(&td->td_lprof[0]) == NULL); 624 MPASS(LIST_FIRST(&td->td_lprof[1]) == NULL); 625 } 626 627 void 628 lock_profile_release_lock(struct lock_object *lo) 629 { 630 struct lock_profile_object *l; 631 struct lock_prof_type *type; 632 struct lock_prof *lp; 633 uint64_t curtime, holdtime; 634 struct lpohead *head; 635 int spin; 636 637 if (SCHEDULER_STOPPED()) 638 return; 639 if (lo->lo_flags & LO_NOPROFILE) 640 return; 641 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 642 head = &curthread->td_lprof[spin]; 643 if (LIST_FIRST(head) == NULL) 644 return; 645 critical_enter(); 646 /* Recheck enabled now that we're in a critical section. */ 647 if (lock_prof_enable == 0 && lock_prof_resetting == 1) 648 goto out; 649 /* 650 * If lock profiling is not enabled we still want to remove the 651 * lpo from our queue. 652 */ 653 LIST_FOREACH(l, head, lpo_link) 654 if (l->lpo_obj == lo) 655 break; 656 if (l == NULL) 657 goto out; 658 if (--l->lpo_ref > 0) 659 goto out; 660 lp = lock_profile_lookup(lo, spin, l->lpo_file, l->lpo_line); 661 if (lp == NULL) 662 goto release; 663 curtime = nanoseconds(); 664 if (curtime < l->lpo_acqtime) 665 goto release; 666 holdtime = curtime - l->lpo_acqtime; 667 668 /* 669 * Record if the lock has been held longer now than ever 670 * before. 671 */ 672 if (holdtime > lp->cnt_max) 673 lp->cnt_max = holdtime; 674 if (l->lpo_waittime > lp->cnt_wait_max) 675 lp->cnt_wait_max = l->lpo_waittime; 676 lp->cnt_tot += holdtime; 677 lp->cnt_wait += l->lpo_waittime; 678 lp->cnt_contest_locking += l->lpo_contest_locking; 679 lp->cnt_cur += l->lpo_cnt; 680 release: 681 LIST_REMOVE(l, lpo_link); 682 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 683 LIST_INSERT_HEAD(&type->lpt_lpoalloc, l, lpo_link); 684 out: 685 critical_exit(); 686 } 687 688 static SYSCTL_NODE(_debug_lock, OID_AUTO, prof, CTLFLAG_RD, NULL, 689 "lock profiling"); 690 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipspin, CTLFLAG_RW, 691 &lock_prof_skipspin, 0, "Skip profiling on spinlocks."); 692 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipcount, CTLFLAG_RW, 693 &lock_prof_skipcount, 0, "Sample approximately every N lock acquisitions."); 694 SYSCTL_INT(_debug_lock_prof, OID_AUTO, rejected, CTLFLAG_RD, 695 &lock_prof_rejected, 0, "Number of rejected profiling records"); 696 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 697 NULL, 0, dump_lock_prof_stats, "A", "Lock profiling statistics"); 698 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 699 NULL, 0, reset_lock_prof_stats, "I", "Reset lock profiling statistics"); 700 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 701 NULL, 0, enable_lock_prof, "I", "Enable lock profiling"); 702 703 #endif 704