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