1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 John Baldwin <jhb@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * This module holds the global variables and functions used to maintain 31 * lock_object structures. 32 */ 33 34 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_ddb.h" 38 #include "opt_mprof.h" 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/kernel.h> 43 #include <sys/ktr.h> 44 #include <sys/lock.h> 45 #include <sys/lock_profile.h> 46 #include <sys/malloc.h> 47 #include <sys/mutex.h> 48 #include <sys/pcpu.h> 49 #include <sys/proc.h> 50 #include <sys/sbuf.h> 51 #include <sys/sched.h> 52 #include <sys/smp.h> 53 #include <sys/sysctl.h> 54 55 #ifdef DDB 56 #include <ddb/ddb.h> 57 #endif 58 59 #include <machine/cpufunc.h> 60 61 SDT_PROVIDER_DEFINE(lock); 62 SDT_PROBE_DEFINE1(lock, , , starvation, "u_int"); 63 64 CTASSERT(LOCK_CLASS_MAX == 15); 65 66 struct lock_class *lock_classes[LOCK_CLASS_MAX + 1] = { 67 &lock_class_mtx_spin, 68 &lock_class_mtx_sleep, 69 &lock_class_sx, 70 &lock_class_rm, 71 &lock_class_rm_sleepable, 72 &lock_class_rw, 73 &lock_class_lockmgr, 74 }; 75 76 void 77 lock_init(struct lock_object *lock, struct lock_class *class, const char *name, 78 const char *type, int flags) 79 { 80 int i; 81 82 /* Check for double-init and zero object. */ 83 KASSERT(flags & LO_NEW || !lock_initialized(lock), 84 ("lock \"%s\" %p already initialized", name, lock)); 85 86 /* Look up lock class to find its index. */ 87 for (i = 0; i < LOCK_CLASS_MAX; i++) 88 if (lock_classes[i] == class) { 89 lock->lo_flags = i << LO_CLASSSHIFT; 90 break; 91 } 92 KASSERT(i < LOCK_CLASS_MAX, ("unknown lock class %p", class)); 93 94 /* Initialize the lock object. */ 95 lock->lo_name = name; 96 lock->lo_flags |= flags | LO_INITIALIZED; 97 LOCK_LOG_INIT(lock, 0); 98 WITNESS_INIT(lock, (type != NULL) ? type : name); 99 } 100 101 void 102 lock_destroy(struct lock_object *lock) 103 { 104 105 KASSERT(lock_initialized(lock), ("lock %p is not initialized", lock)); 106 WITNESS_DESTROY(lock); 107 LOCK_LOG_DESTROY(lock, 0); 108 lock->lo_flags &= ~LO_INITIALIZED; 109 } 110 111 static SYSCTL_NODE(_debug, OID_AUTO, lock, CTLFLAG_RD, NULL, "lock debugging"); 112 static SYSCTL_NODE(_debug_lock, OID_AUTO, delay, CTLFLAG_RD, NULL, 113 "lock delay"); 114 115 static u_int __read_mostly starvation_limit = 131072; 116 SYSCTL_INT(_debug_lock_delay, OID_AUTO, starvation_limit, CTLFLAG_RW, 117 &starvation_limit, 0, ""); 118 119 static u_int __read_mostly restrict_starvation = 0; 120 SYSCTL_INT(_debug_lock_delay, OID_AUTO, restrict_starvation, CTLFLAG_RW, 121 &restrict_starvation, 0, ""); 122 123 void 124 lock_delay(struct lock_delay_arg *la) 125 { 126 struct lock_delay_config *lc = la->config; 127 u_int i; 128 129 la->delay <<= 1; 130 if (__predict_false(la->delay > lc->max)) 131 la->delay = lc->max; 132 133 for (i = la->delay; i > 0; i--) 134 cpu_spinwait(); 135 136 la->spin_cnt += la->delay; 137 if (__predict_false(la->spin_cnt > starvation_limit)) { 138 SDT_PROBE1(lock, , , starvation, la->delay); 139 if (restrict_starvation) 140 la->delay = lc->base; 141 } 142 } 143 144 static u_int 145 lock_roundup_2(u_int val) 146 { 147 u_int res; 148 149 for (res = 1; res <= val; res <<= 1) 150 continue; 151 152 return (res); 153 } 154 155 void 156 lock_delay_default_init(struct lock_delay_config *lc) 157 { 158 159 lc->base = lock_roundup_2(mp_ncpus) / 4; 160 lc->max = lc->base * 1024; 161 } 162 163 #ifdef DDB 164 DB_SHOW_COMMAND(lock, db_show_lock) 165 { 166 struct lock_object *lock; 167 struct lock_class *class; 168 169 if (!have_addr) 170 return; 171 lock = (struct lock_object *)addr; 172 if (LO_CLASSINDEX(lock) > LOCK_CLASS_MAX) { 173 db_printf("Unknown lock class: %d\n", LO_CLASSINDEX(lock)); 174 return; 175 } 176 class = LOCK_CLASS(lock); 177 db_printf(" class: %s\n", class->lc_name); 178 db_printf(" name: %s\n", lock->lo_name); 179 class->lc_ddb_show(lock); 180 } 181 #endif 182 183 #ifdef LOCK_PROFILING 184 185 /* 186 * One object per-thread for each lock the thread owns. Tracks individual 187 * lock instances. 188 */ 189 struct lock_profile_object { 190 LIST_ENTRY(lock_profile_object) lpo_link; 191 struct lock_object *lpo_obj; 192 const char *lpo_file; 193 int lpo_line; 194 uint16_t lpo_ref; 195 uint16_t lpo_cnt; 196 uint64_t lpo_acqtime; 197 uint64_t lpo_waittime; 198 u_int lpo_contest_locking; 199 }; 200 201 /* 202 * One lock_prof for each (file, line, lock object) triple. 203 */ 204 struct lock_prof { 205 SLIST_ENTRY(lock_prof) link; 206 struct lock_class *class; 207 const char *file; 208 const char *name; 209 int line; 210 int ticks; 211 uintmax_t cnt_wait_max; 212 uintmax_t cnt_max; 213 uintmax_t cnt_tot; 214 uintmax_t cnt_wait; 215 uintmax_t cnt_cur; 216 uintmax_t cnt_contest_locking; 217 }; 218 219 SLIST_HEAD(lphead, lock_prof); 220 221 #define LPROF_HASH_SIZE 4096 222 #define LPROF_HASH_MASK (LPROF_HASH_SIZE - 1) 223 #define LPROF_CACHE_SIZE 4096 224 225 /* 226 * Array of objects and profs for each type of object for each cpu. Spinlocks 227 * are handled separately because a thread may be preempted and acquire a 228 * spinlock while in the lock profiling code of a non-spinlock. In this way 229 * we only need a critical section to protect the per-cpu lists. 230 */ 231 struct lock_prof_type { 232 struct lphead lpt_lpalloc; 233 struct lpohead lpt_lpoalloc; 234 struct lphead lpt_hash[LPROF_HASH_SIZE]; 235 struct lock_prof lpt_prof[LPROF_CACHE_SIZE]; 236 struct lock_profile_object lpt_objs[LPROF_CACHE_SIZE]; 237 }; 238 239 struct lock_prof_cpu { 240 struct lock_prof_type lpc_types[2]; /* One for spin one for other. */ 241 }; 242 243 struct lock_prof_cpu *lp_cpu[MAXCPU]; 244 245 volatile int __read_mostly lock_prof_enable; 246 static volatile int lock_prof_resetting; 247 248 #define LPROF_SBUF_SIZE 256 249 250 static int lock_prof_rejected; 251 static int lock_prof_skipspin; 252 static int lock_prof_skipcount; 253 254 #ifndef USE_CPU_NANOSECONDS 255 uint64_t 256 nanoseconds(void) 257 { 258 struct bintime bt; 259 uint64_t ns; 260 261 binuptime(&bt); 262 /* From bintime2timespec */ 263 ns = bt.sec * (uint64_t)1000000000; 264 ns += ((uint64_t)1000000000 * (uint32_t)(bt.frac >> 32)) >> 32; 265 return (ns); 266 } 267 #endif 268 269 static void 270 lock_prof_init_type(struct lock_prof_type *type) 271 { 272 int i; 273 274 SLIST_INIT(&type->lpt_lpalloc); 275 LIST_INIT(&type->lpt_lpoalloc); 276 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 277 SLIST_INSERT_HEAD(&type->lpt_lpalloc, &type->lpt_prof[i], 278 link); 279 LIST_INSERT_HEAD(&type->lpt_lpoalloc, &type->lpt_objs[i], 280 lpo_link); 281 } 282 } 283 284 static void 285 lock_prof_init(void *arg) 286 { 287 int cpu; 288 289 for (cpu = 0; cpu <= mp_maxid; cpu++) { 290 lp_cpu[cpu] = malloc(sizeof(*lp_cpu[cpu]), M_DEVBUF, 291 M_WAITOK | M_ZERO); 292 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[0]); 293 lock_prof_init_type(&lp_cpu[cpu]->lpc_types[1]); 294 } 295 } 296 SYSINIT(lockprof, SI_SUB_SMP, SI_ORDER_ANY, lock_prof_init, NULL); 297 298 static void 299 lock_prof_reset_wait(void) 300 { 301 302 /* 303 * Spin relinquishing our cpu so that quiesce_all_cpus may 304 * complete. 305 */ 306 while (lock_prof_resetting) 307 sched_relinquish(curthread); 308 } 309 310 static void 311 lock_prof_reset(void) 312 { 313 struct lock_prof_cpu *lpc; 314 int enabled, i, cpu; 315 316 /* 317 * We not only race with acquiring and releasing locks but also 318 * thread exit. To be certain that threads exit without valid head 319 * pointers they must see resetting set before enabled is cleared. 320 * Otherwise a lock may not be removed from a per-thread list due 321 * to disabled being set but not wait for reset() to remove it below. 322 */ 323 atomic_store_rel_int(&lock_prof_resetting, 1); 324 enabled = lock_prof_enable; 325 lock_prof_enable = 0; 326 quiesce_all_cpus("profreset", 0); 327 /* 328 * Some objects may have migrated between CPUs. Clear all links 329 * before we zero the structures. Some items may still be linked 330 * into per-thread lists as well. 331 */ 332 for (cpu = 0; cpu <= mp_maxid; cpu++) { 333 lpc = lp_cpu[cpu]; 334 for (i = 0; i < LPROF_CACHE_SIZE; i++) { 335 LIST_REMOVE(&lpc->lpc_types[0].lpt_objs[i], lpo_link); 336 LIST_REMOVE(&lpc->lpc_types[1].lpt_objs[i], lpo_link); 337 } 338 } 339 for (cpu = 0; cpu <= mp_maxid; cpu++) { 340 lpc = lp_cpu[cpu]; 341 bzero(lpc, sizeof(*lpc)); 342 lock_prof_init_type(&lpc->lpc_types[0]); 343 lock_prof_init_type(&lpc->lpc_types[1]); 344 } 345 atomic_store_rel_int(&lock_prof_resetting, 0); 346 lock_prof_enable = enabled; 347 } 348 349 static void 350 lock_prof_output(struct lock_prof *lp, struct sbuf *sb) 351 { 352 const char *p; 353 354 for (p = lp->file; p != NULL && strncmp(p, "../", 3) == 0; p += 3); 355 sbuf_printf(sb, 356 "%8ju %9ju %11ju %11ju %11ju %6ju %6ju %2ju %6ju %s:%d (%s:%s)\n", 357 lp->cnt_max / 1000, lp->cnt_wait_max / 1000, lp->cnt_tot / 1000, 358 lp->cnt_wait / 1000, lp->cnt_cur, 359 lp->cnt_cur == 0 ? (uintmax_t)0 : 360 lp->cnt_tot / (lp->cnt_cur * 1000), 361 lp->cnt_cur == 0 ? (uintmax_t)0 : 362 lp->cnt_wait / (lp->cnt_cur * 1000), 363 (uintmax_t)0, lp->cnt_contest_locking, 364 p, lp->line, lp->class->lc_name, lp->name); 365 } 366 367 static void 368 lock_prof_sum(struct lock_prof *match, struct lock_prof *dst, int hash, 369 int spin, int t) 370 { 371 struct lock_prof_type *type; 372 struct lock_prof *l; 373 int cpu; 374 375 dst->file = match->file; 376 dst->line = match->line; 377 dst->class = match->class; 378 dst->name = match->name; 379 380 for (cpu = 0; cpu <= mp_maxid; cpu++) { 381 if (lp_cpu[cpu] == NULL) 382 continue; 383 type = &lp_cpu[cpu]->lpc_types[spin]; 384 SLIST_FOREACH(l, &type->lpt_hash[hash], link) { 385 if (l->ticks == t) 386 continue; 387 if (l->file != match->file || l->line != match->line || 388 l->name != match->name) 389 continue; 390 l->ticks = t; 391 if (l->cnt_max > dst->cnt_max) 392 dst->cnt_max = l->cnt_max; 393 if (l->cnt_wait_max > dst->cnt_wait_max) 394 dst->cnt_wait_max = l->cnt_wait_max; 395 dst->cnt_tot += l->cnt_tot; 396 dst->cnt_wait += l->cnt_wait; 397 dst->cnt_cur += l->cnt_cur; 398 dst->cnt_contest_locking += l->cnt_contest_locking; 399 } 400 } 401 402 } 403 404 static void 405 lock_prof_type_stats(struct lock_prof_type *type, struct sbuf *sb, int spin, 406 int t) 407 { 408 struct lock_prof *l; 409 int i; 410 411 for (i = 0; i < LPROF_HASH_SIZE; ++i) { 412 SLIST_FOREACH(l, &type->lpt_hash[i], link) { 413 struct lock_prof lp = {}; 414 415 if (l->ticks == t) 416 continue; 417 lock_prof_sum(l, &lp, i, spin, t); 418 lock_prof_output(&lp, sb); 419 } 420 } 421 } 422 423 static int 424 dump_lock_prof_stats(SYSCTL_HANDLER_ARGS) 425 { 426 struct sbuf *sb; 427 int error, cpu, t; 428 int enabled; 429 430 error = sysctl_wire_old_buffer(req, 0); 431 if (error != 0) 432 return (error); 433 sb = sbuf_new_for_sysctl(NULL, NULL, LPROF_SBUF_SIZE, req); 434 sbuf_printf(sb, "\n%8s %9s %11s %11s %11s %6s %6s %2s %6s %s\n", 435 "max", "wait_max", "total", "wait_total", "count", "avg", "wait_avg", "cnt_hold", "cnt_lock", "name"); 436 enabled = lock_prof_enable; 437 lock_prof_enable = 0; 438 quiesce_all_cpus("profstat", 0); 439 t = ticks; 440 for (cpu = 0; cpu <= mp_maxid; cpu++) { 441 if (lp_cpu[cpu] == NULL) 442 continue; 443 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[0], sb, 0, t); 444 lock_prof_type_stats(&lp_cpu[cpu]->lpc_types[1], sb, 1, t); 445 } 446 lock_prof_enable = enabled; 447 448 error = sbuf_finish(sb); 449 /* Output a trailing NUL. */ 450 if (error == 0) 451 error = SYSCTL_OUT(req, "", 1); 452 sbuf_delete(sb); 453 return (error); 454 } 455 456 static int 457 enable_lock_prof(SYSCTL_HANDLER_ARGS) 458 { 459 int error, v; 460 461 v = lock_prof_enable; 462 error = sysctl_handle_int(oidp, &v, v, req); 463 if (error) 464 return (error); 465 if (req->newptr == NULL) 466 return (error); 467 if (v == lock_prof_enable) 468 return (0); 469 if (v == 1) 470 lock_prof_reset(); 471 lock_prof_enable = !!v; 472 473 return (0); 474 } 475 476 static int 477 reset_lock_prof_stats(SYSCTL_HANDLER_ARGS) 478 { 479 int error, v; 480 481 v = 0; 482 error = sysctl_handle_int(oidp, &v, 0, req); 483 if (error) 484 return (error); 485 if (req->newptr == NULL) 486 return (error); 487 if (v == 0) 488 return (0); 489 lock_prof_reset(); 490 491 return (0); 492 } 493 494 static struct lock_prof * 495 lock_profile_lookup(struct lock_object *lo, int spin, const char *file, 496 int line) 497 { 498 const char *unknown = "(unknown)"; 499 struct lock_prof_type *type; 500 struct lock_prof *lp; 501 struct lphead *head; 502 const char *p; 503 u_int hash; 504 505 p = file; 506 if (p == NULL || *p == '\0') 507 p = unknown; 508 hash = (uintptr_t)lo->lo_name * 31 + (uintptr_t)p * 31 + line; 509 hash &= LPROF_HASH_MASK; 510 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 511 head = &type->lpt_hash[hash]; 512 SLIST_FOREACH(lp, head, link) { 513 if (lp->line == line && lp->file == p && 514 lp->name == lo->lo_name) 515 return (lp); 516 517 } 518 lp = SLIST_FIRST(&type->lpt_lpalloc); 519 if (lp == NULL) { 520 lock_prof_rejected++; 521 return (lp); 522 } 523 SLIST_REMOVE_HEAD(&type->lpt_lpalloc, link); 524 lp->file = p; 525 lp->line = line; 526 lp->class = LOCK_CLASS(lo); 527 lp->name = lo->lo_name; 528 SLIST_INSERT_HEAD(&type->lpt_hash[hash], lp, link); 529 return (lp); 530 } 531 532 static struct lock_profile_object * 533 lock_profile_object_lookup(struct lock_object *lo, int spin, const char *file, 534 int line) 535 { 536 struct lock_profile_object *l; 537 struct lock_prof_type *type; 538 struct lpohead *head; 539 540 head = &curthread->td_lprof[spin]; 541 LIST_FOREACH(l, head, lpo_link) 542 if (l->lpo_obj == lo && l->lpo_file == file && 543 l->lpo_line == line) 544 return (l); 545 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 546 l = LIST_FIRST(&type->lpt_lpoalloc); 547 if (l == NULL) { 548 lock_prof_rejected++; 549 return (NULL); 550 } 551 LIST_REMOVE(l, lpo_link); 552 l->lpo_obj = lo; 553 l->lpo_file = file; 554 l->lpo_line = line; 555 l->lpo_cnt = 0; 556 LIST_INSERT_HEAD(head, l, lpo_link); 557 558 return (l); 559 } 560 561 void 562 lock_profile_obtain_lock_success(struct lock_object *lo, int contested, 563 uint64_t waittime, const char *file, int line) 564 { 565 static int lock_prof_count; 566 struct lock_profile_object *l; 567 int spin; 568 569 if (SCHEDULER_STOPPED()) 570 return; 571 572 /* don't reset the timer when/if recursing */ 573 if (!lock_prof_enable || (lo->lo_flags & LO_NOPROFILE)) 574 return; 575 if (lock_prof_skipcount && 576 (++lock_prof_count % lock_prof_skipcount) != 0) 577 return; 578 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 579 if (spin && lock_prof_skipspin == 1) 580 return; 581 critical_enter(); 582 /* Recheck enabled now that we're in a critical section. */ 583 if (lock_prof_enable == 0) 584 goto out; 585 l = lock_profile_object_lookup(lo, spin, file, line); 586 if (l == NULL) 587 goto out; 588 l->lpo_cnt++; 589 if (++l->lpo_ref > 1) 590 goto out; 591 l->lpo_contest_locking = contested; 592 l->lpo_acqtime = nanoseconds(); 593 if (waittime && (l->lpo_acqtime > waittime)) 594 l->lpo_waittime = l->lpo_acqtime - waittime; 595 else 596 l->lpo_waittime = 0; 597 out: 598 critical_exit(); 599 } 600 601 void 602 lock_profile_thread_exit(struct thread *td) 603 { 604 #ifdef INVARIANTS 605 struct lock_profile_object *l; 606 607 MPASS(curthread->td_critnest == 0); 608 #endif 609 /* 610 * If lock profiling was disabled we have to wait for reset to 611 * clear our pointers before we can exit safely. 612 */ 613 lock_prof_reset_wait(); 614 #ifdef INVARIANTS 615 LIST_FOREACH(l, &td->td_lprof[0], lpo_link) 616 printf("thread still holds lock acquired at %s:%d\n", 617 l->lpo_file, l->lpo_line); 618 LIST_FOREACH(l, &td->td_lprof[1], lpo_link) 619 printf("thread still holds lock acquired at %s:%d\n", 620 l->lpo_file, l->lpo_line); 621 #endif 622 MPASS(LIST_FIRST(&td->td_lprof[0]) == NULL); 623 MPASS(LIST_FIRST(&td->td_lprof[1]) == NULL); 624 } 625 626 void 627 lock_profile_release_lock(struct lock_object *lo) 628 { 629 struct lock_profile_object *l; 630 struct lock_prof_type *type; 631 struct lock_prof *lp; 632 uint64_t curtime, holdtime; 633 struct lpohead *head; 634 int spin; 635 636 if (SCHEDULER_STOPPED()) 637 return; 638 if (lo->lo_flags & LO_NOPROFILE) 639 return; 640 spin = (LOCK_CLASS(lo)->lc_flags & LC_SPINLOCK) ? 1 : 0; 641 head = &curthread->td_lprof[spin]; 642 if (LIST_FIRST(head) == NULL) 643 return; 644 critical_enter(); 645 /* Recheck enabled now that we're in a critical section. */ 646 if (lock_prof_enable == 0 && lock_prof_resetting == 1) 647 goto out; 648 /* 649 * If lock profiling is not enabled we still want to remove the 650 * lpo from our queue. 651 */ 652 LIST_FOREACH(l, head, lpo_link) 653 if (l->lpo_obj == lo) 654 break; 655 if (l == NULL) 656 goto out; 657 if (--l->lpo_ref > 0) 658 goto out; 659 lp = lock_profile_lookup(lo, spin, l->lpo_file, l->lpo_line); 660 if (lp == NULL) 661 goto release; 662 curtime = nanoseconds(); 663 if (curtime < l->lpo_acqtime) 664 goto release; 665 holdtime = curtime - l->lpo_acqtime; 666 667 /* 668 * Record if the lock has been held longer now than ever 669 * before. 670 */ 671 if (holdtime > lp->cnt_max) 672 lp->cnt_max = holdtime; 673 if (l->lpo_waittime > lp->cnt_wait_max) 674 lp->cnt_wait_max = l->lpo_waittime; 675 lp->cnt_tot += holdtime; 676 lp->cnt_wait += l->lpo_waittime; 677 lp->cnt_contest_locking += l->lpo_contest_locking; 678 lp->cnt_cur += l->lpo_cnt; 679 release: 680 LIST_REMOVE(l, lpo_link); 681 type = &lp_cpu[PCPU_GET(cpuid)]->lpc_types[spin]; 682 LIST_INSERT_HEAD(&type->lpt_lpoalloc, l, lpo_link); 683 out: 684 critical_exit(); 685 } 686 687 static SYSCTL_NODE(_debug_lock, OID_AUTO, prof, CTLFLAG_RD, NULL, 688 "lock profiling"); 689 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipspin, CTLFLAG_RW, 690 &lock_prof_skipspin, 0, "Skip profiling on spinlocks."); 691 SYSCTL_INT(_debug_lock_prof, OID_AUTO, skipcount, CTLFLAG_RW, 692 &lock_prof_skipcount, 0, "Sample approximately every N lock acquisitions."); 693 SYSCTL_INT(_debug_lock_prof, OID_AUTO, rejected, CTLFLAG_RD, 694 &lock_prof_rejected, 0, "Number of rejected profiling records"); 695 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, stats, CTLTYPE_STRING | CTLFLAG_RD, 696 NULL, 0, dump_lock_prof_stats, "A", "Lock profiling statistics"); 697 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, reset, CTLTYPE_INT | CTLFLAG_RW, 698 NULL, 0, reset_lock_prof_stats, "I", "Reset lock profiling statistics"); 699 SYSCTL_PROC(_debug_lock_prof, OID_AUTO, enable, CTLTYPE_INT | CTLFLAG_RW, 700 NULL, 0, enable_lock_prof, "I", "Enable lock profiling"); 701 702 #endif 703