1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. 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 * 3. Berkeley Software Design Inc's name may not be used to endorse or 15 * promote products derived from this software without specific prior 16 * written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ 31 * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ 32 */ 33 34/* 35 * Machine independent bits of mutex implementation. 36 */ 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD$"); 40 41#include "opt_adaptive_mutexes.h" 42#include "opt_ddb.h" 43#include "opt_hwpmc_hooks.h" 44#include "opt_sched.h" 45 46#include <sys/param.h> 47#include <sys/systm.h> 48#include <sys/bus.h> 49#include <sys/conf.h> 50#include <sys/kdb.h> 51#include <sys/kernel.h> 52#include <sys/ktr.h> 53#include <sys/lock.h> 54#include <sys/malloc.h> 55#include <sys/mutex.h> 56#include <sys/proc.h> 57#include <sys/resourcevar.h> 58#include <sys/sched.h> 59#include <sys/sbuf.h> 60#include <sys/smp.h> 61#include <sys/sysctl.h> 62#include <sys/turnstile.h> 63#include <sys/vmmeter.h> 64#include <sys/lock_profile.h> 65 66#include <machine/atomic.h> 67#include <machine/bus.h> 68#include <machine/cpu.h> 69 70#include <ddb/ddb.h> 71 72#include <fs/devfs/devfs_int.h> 73 74#include <vm/vm.h> 75#include <vm/vm_extern.h> 76 77#if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES) 78#define ADAPTIVE_MUTEXES 79#endif 80 81#ifdef HWPMC_HOOKS 82#include <sys/pmckern.h> 83PMC_SOFT_DEFINE( , , lock, failed); 84#endif 85 86/* 87 * Return the mutex address when the lock cookie address is provided. 88 * This functionality assumes that struct mtx* have a member named mtx_lock. 89 */ 90#define mtxlock2mtx(c) (__containerof(c, struct mtx, mtx_lock)) 91 92/* 93 * Internal utility macros. 94 */ 95#define mtx_unowned(m) ((m)->mtx_lock == MTX_UNOWNED) 96 97#define mtx_destroyed(m) ((m)->mtx_lock == MTX_DESTROYED) 98 99static void assert_mtx(const struct lock_object *lock, int what); 100#ifdef DDB 101static void db_show_mtx(const struct lock_object *lock); 102#endif 103static void lock_mtx(struct lock_object *lock, uintptr_t how); 104static void lock_spin(struct lock_object *lock, uintptr_t how); 105#ifdef KDTRACE_HOOKS 106static int owner_mtx(const struct lock_object *lock, 107 struct thread **owner); 108#endif 109static uintptr_t unlock_mtx(struct lock_object *lock); 110static uintptr_t unlock_spin(struct lock_object *lock); 111 112/* 113 * Lock classes for sleep and spin mutexes. 114 */ 115struct lock_class lock_class_mtx_sleep = { 116 .lc_name = "sleep mutex", 117 .lc_flags = LC_SLEEPLOCK | LC_RECURSABLE, 118 .lc_assert = assert_mtx, 119#ifdef DDB 120 .lc_ddb_show = db_show_mtx, 121#endif 122 .lc_lock = lock_mtx, 123 .lc_unlock = unlock_mtx, 124#ifdef KDTRACE_HOOKS 125 .lc_owner = owner_mtx, 126#endif 127}; 128struct lock_class lock_class_mtx_spin = { 129 .lc_name = "spin mutex", 130 .lc_flags = LC_SPINLOCK | LC_RECURSABLE, 131 .lc_assert = assert_mtx, 132#ifdef DDB 133 .lc_ddb_show = db_show_mtx, 134#endif 135 .lc_lock = lock_spin, 136 .lc_unlock = unlock_spin, 137#ifdef KDTRACE_HOOKS 138 .lc_owner = owner_mtx, 139#endif 140}; 141 142#ifdef ADAPTIVE_MUTEXES 143static SYSCTL_NODE(_debug, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mtx debugging"); 144 145static struct lock_delay_config __read_frequently mtx_delay; 146 147SYSCTL_INT(_debug_mtx, OID_AUTO, delay_base, CTLFLAG_RW, &mtx_delay.base, 148 0, ""); 149SYSCTL_INT(_debug_mtx, OID_AUTO, delay_max, CTLFLAG_RW, &mtx_delay.max, 150 0, ""); 151 152LOCK_DELAY_SYSINIT_DEFAULT(mtx_delay); 153#endif 154 155static SYSCTL_NODE(_debug, OID_AUTO, mtx_spin, CTLFLAG_RD, NULL, 156 "mtx spin debugging"); 157 158static struct lock_delay_config __read_frequently mtx_spin_delay; 159 160SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_base, CTLFLAG_RW, 161 &mtx_spin_delay.base, 0, ""); 162SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_max, CTLFLAG_RW, 163 &mtx_spin_delay.max, 0, ""); 164 165LOCK_DELAY_SYSINIT_DEFAULT(mtx_spin_delay); 166 167/* 168 * System-wide mutexes 169 */ 170struct mtx blocked_lock; 171struct mtx __exclusive_cache_line Giant; 172 173static void _mtx_lock_indefinite_check(struct mtx *, struct lock_delay_arg *); 174 175void 176assert_mtx(const struct lock_object *lock, int what) 177{ 178 179 /* 180 * Treat LA_LOCKED as if LA_XLOCKED was asserted. 181 * 182 * Some callers of lc_assert uses LA_LOCKED to indicate that either 183 * a shared lock or write lock was held, while other callers uses 184 * the more strict LA_XLOCKED (used as MA_OWNED). 185 * 186 * Mutex is the only lock class that can not be shared, as a result, 187 * we can reasonably consider the caller really intends to assert 188 * LA_XLOCKED when they are asserting LA_LOCKED on a mutex object. 189 */ 190 if (what & LA_LOCKED) { 191 what &= ~LA_LOCKED; 192 what |= LA_XLOCKED; 193 } 194 mtx_assert((const struct mtx *)lock, what); 195} 196 197void 198lock_mtx(struct lock_object *lock, uintptr_t how) 199{ 200 201 mtx_lock((struct mtx *)lock); 202} 203 204void 205lock_spin(struct lock_object *lock, uintptr_t how) 206{ 207 208 panic("spin locks can only use msleep_spin"); 209} 210 211uintptr_t 212unlock_mtx(struct lock_object *lock) 213{ 214 struct mtx *m; 215 216 m = (struct mtx *)lock; 217 mtx_assert(m, MA_OWNED | MA_NOTRECURSED); 218 mtx_unlock(m); 219 return (0); 220} 221 222uintptr_t 223unlock_spin(struct lock_object *lock) 224{ 225 226 panic("spin locks can only use msleep_spin"); 227} 228 229#ifdef KDTRACE_HOOKS 230int 231owner_mtx(const struct lock_object *lock, struct thread **owner) 232{ 233 const struct mtx *m; 234 uintptr_t x; 235 236 m = (const struct mtx *)lock; 237 x = m->mtx_lock; 238 *owner = (struct thread *)(x & ~MTX_FLAGMASK); 239 return (*owner != NULL); 240} 241#endif 242 243/* 244 * Function versions of the inlined __mtx_* macros. These are used by 245 * modules and can also be called from assembly language if needed. 246 */ 247void 248__mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line) 249{ 250 struct mtx *m; 251 uintptr_t tid, v; 252 253 m = mtxlock2mtx(c); 254 255 KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() || 256 !TD_IS_IDLETHREAD(curthread), 257 ("mtx_lock() by idle thread %p on sleep mutex %s @ %s:%d", 258 curthread, m->lock_object.lo_name, file, line)); 259 KASSERT(m->mtx_lock != MTX_DESTROYED, 260 ("mtx_lock() of destroyed mutex @ %s:%d", file, line)); 261 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 262 ("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 263 file, line)); 264 WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) | 265 LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); 266 267 tid = (uintptr_t)curthread; 268 v = MTX_UNOWNED; 269 if (!_mtx_obtain_lock_fetch(m, &v, tid)) 270 _mtx_lock_sleep(m, v, opts, file, line); 271 else 272 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, 273 m, 0, 0, file, line); 274 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 275 line); 276 WITNESS_LOCK(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_EXCLUSIVE, 277 file, line); 278 TD_LOCKS_INC(curthread); 279} 280 281void 282__mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line) 283{ 284 struct mtx *m; 285 286 m = mtxlock2mtx(c); 287 288 KASSERT(m->mtx_lock != MTX_DESTROYED, 289 ("mtx_unlock() of destroyed mutex @ %s:%d", file, line)); 290 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 291 ("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 292 file, line)); 293 WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 294 LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, 295 line); 296 mtx_assert(m, MA_OWNED); 297 298#ifdef LOCK_PROFILING 299 __mtx_unlock_sleep(c, (uintptr_t)curthread, opts, file, line); 300#else 301 __mtx_unlock(m, curthread, opts, file, line); 302#endif 303 TD_LOCKS_DEC(curthread); 304} 305 306void 307__mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 308 int line) 309{ 310 struct mtx *m; 311#ifdef SMP 312 uintptr_t tid, v; 313#endif 314 315 m = mtxlock2mtx(c); 316 317 KASSERT(m->mtx_lock != MTX_DESTROYED, 318 ("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line)); 319 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 320 ("mtx_lock_spin() of sleep mutex %s @ %s:%d", 321 m->lock_object.lo_name, file, line)); 322 if (mtx_owned(m)) 323 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 324 (opts & MTX_RECURSE) != 0, 325 ("mtx_lock_spin: recursed on non-recursive mutex %s @ %s:%d\n", 326 m->lock_object.lo_name, file, line)); 327 opts &= ~MTX_RECURSE; 328 WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, 329 file, line, NULL); 330#ifdef SMP 331 spinlock_enter(); 332 tid = (uintptr_t)curthread; 333 v = MTX_UNOWNED; 334 if (!_mtx_obtain_lock_fetch(m, &v, tid)) 335 _mtx_lock_spin(m, v, opts, file, line); 336 else 337 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, 338 m, 0, 0, file, line); 339#else 340 __mtx_lock_spin(m, curthread, opts, file, line); 341#endif 342 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 343 line); 344 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 345} 346 347int 348__mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 349 int line) 350{ 351 struct mtx *m; 352 353 if (SCHEDULER_STOPPED()) 354 return (1); 355 356 m = mtxlock2mtx(c); 357 358 KASSERT(m->mtx_lock != MTX_DESTROYED, 359 ("mtx_trylock_spin() of destroyed mutex @ %s:%d", file, line)); 360 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 361 ("mtx_trylock_spin() of sleep mutex %s @ %s:%d", 362 m->lock_object.lo_name, file, line)); 363 KASSERT((opts & MTX_RECURSE) == 0, 364 ("mtx_trylock_spin: unsupp. opt MTX_RECURSE on mutex %s @ %s:%d\n", 365 m->lock_object.lo_name, file, line)); 366 if (__mtx_trylock_spin(m, curthread, opts, file, line)) { 367 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 1, file, line); 368 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 369 return (1); 370 } 371 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 0, file, line); 372 return (0); 373} 374 375void 376__mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 377 int line) 378{ 379 struct mtx *m; 380 381 m = mtxlock2mtx(c); 382 383 KASSERT(m->mtx_lock != MTX_DESTROYED, 384 ("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line)); 385 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 386 ("mtx_unlock_spin() of sleep mutex %s @ %s:%d", 387 m->lock_object.lo_name, file, line)); 388 WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 389 LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, 390 line); 391 mtx_assert(m, MA_OWNED); 392 393 __mtx_unlock_spin(m); 394} 395 396/* 397 * The important part of mtx_trylock{,_flags}() 398 * Tries to acquire lock `m.' If this function is called on a mutex that 399 * is already owned, it will recursively acquire the lock. 400 */ 401int 402_mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF) 403{ 404 struct thread *td; 405 uintptr_t tid, v; 406#ifdef LOCK_PROFILING 407 uint64_t waittime = 0; 408 int contested = 0; 409#endif 410 int rval; 411 bool recursed; 412 413 td = curthread; 414 tid = (uintptr_t)td; 415 if (SCHEDULER_STOPPED_TD(td)) 416 return (1); 417 418 KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td), 419 ("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d", 420 curthread, m->lock_object.lo_name, file, line)); 421 KASSERT(m->mtx_lock != MTX_DESTROYED, 422 ("mtx_trylock() of destroyed mutex @ %s:%d", file, line)); 423 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 424 ("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 425 file, line)); 426 427 rval = 1; 428 recursed = false; 429 v = MTX_UNOWNED; 430 for (;;) { 431 if (_mtx_obtain_lock_fetch(m, &v, tid)) 432 break; 433 if (v == MTX_UNOWNED) 434 continue; 435 if (v == tid && 436 ((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 437 (opts & MTX_RECURSE) != 0)) { 438 m->mtx_recurse++; 439 atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); 440 recursed = true; 441 break; 442 } 443 rval = 0; 444 break; 445 } 446 447 opts &= ~MTX_RECURSE; 448 449 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line); 450 if (rval) { 451 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK, 452 file, line); 453 TD_LOCKS_INC(curthread); 454 if (!recursed) 455 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, 456 m, contested, waittime, file, line); 457 } 458 459 return (rval); 460} 461 462int 463_mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, int line) 464{ 465 struct mtx *m; 466 467 m = mtxlock2mtx(c); 468 return (_mtx_trylock_flags_int(m, opts LOCK_FILE_LINE_ARG)); 469} 470 471/* 472 * __mtx_lock_sleep: the tougher part of acquiring an MTX_DEF lock. 473 * 474 * We call this if the lock is either contested (i.e. we need to go to 475 * sleep waiting for it), or if we need to recurse on it. 476 */ 477#if LOCK_DEBUG > 0 478void 479__mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, const char *file, 480 int line) 481#else 482void 483__mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v) 484#endif 485{ 486 struct thread *td; 487 struct mtx *m; 488 struct turnstile *ts; 489 uintptr_t tid; 490 struct thread *owner; 491#ifdef LOCK_PROFILING 492 int contested = 0; 493 uint64_t waittime = 0; 494#endif 495#if defined(ADAPTIVE_MUTEXES) || defined(KDTRACE_HOOKS) 496 struct lock_delay_arg lda; 497#endif 498#ifdef KDTRACE_HOOKS 499 u_int sleep_cnt = 0; 500 int64_t sleep_time = 0; 501 int64_t all_time = 0; 502#endif 503#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 504 int doing_lockprof = 0; 505#endif 506 507 td = curthread; 508 tid = (uintptr_t)td; 509 m = mtxlock2mtx(c); 510 511#ifdef KDTRACE_HOOKS 512 if (LOCKSTAT_PROFILE_ENABLED(adaptive__acquire)) { 513 while (v == MTX_UNOWNED) { 514 if (_mtx_obtain_lock_fetch(m, &v, tid)) 515 goto out_lockstat; 516 } 517 doing_lockprof = 1; 518 all_time -= lockstat_nsecs(&m->lock_object); 519 } 520#endif 521#ifdef LOCK_PROFILING 522 doing_lockprof = 1; 523#endif 524 525 if (SCHEDULER_STOPPED_TD(td)) 526 return; 527 528#if defined(ADAPTIVE_MUTEXES) 529 lock_delay_arg_init(&lda, &mtx_delay); 530#elif defined(KDTRACE_HOOKS) 531 lock_delay_arg_init(&lda, NULL); 532#endif 533 534 if (__predict_false(v == MTX_UNOWNED)) 535 v = MTX_READ_VALUE(m); 536 537 if (__predict_false(lv_mtx_owner(v) == td)) { 538 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 539 (opts & MTX_RECURSE) != 0, 540 ("_mtx_lock_sleep: recursed on non-recursive mutex %s @ %s:%d\n", 541 m->lock_object.lo_name, file, line)); 542#if LOCK_DEBUG > 0 543 opts &= ~MTX_RECURSE; 544#endif 545 m->mtx_recurse++; 546 atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); 547 if (LOCK_LOG_TEST(&m->lock_object, opts)) 548 CTR1(KTR_LOCK, "_mtx_lock_sleep: %p recursing", m); 549 return; 550 } 551#if LOCK_DEBUG > 0 552 opts &= ~MTX_RECURSE; 553#endif 554 555#ifdef HWPMC_HOOKS 556 PMC_SOFT_CALL( , , lock, failed); 557#endif 558 lock_profile_obtain_lock_failed(&m->lock_object, 559 &contested, &waittime); 560 if (LOCK_LOG_TEST(&m->lock_object, opts)) 561 CTR4(KTR_LOCK, 562 "_mtx_lock_sleep: %s contested (lock=%p) at %s:%d", 563 m->lock_object.lo_name, (void *)m->mtx_lock, file, line); 564 565 for (;;) { 566 if (v == MTX_UNOWNED) { 567 if (_mtx_obtain_lock_fetch(m, &v, tid)) 568 break; 569 continue; 570 } 571#ifdef KDTRACE_HOOKS 572 lda.spin_cnt++; 573#endif 574#ifdef ADAPTIVE_MUTEXES 575 /* 576 * If the owner is running on another CPU, spin until the 577 * owner stops running or the state of the lock changes. 578 */ 579 owner = lv_mtx_owner(v); 580 if (TD_IS_RUNNING(owner)) { 581 if (LOCK_LOG_TEST(&m->lock_object, 0)) 582 CTR3(KTR_LOCK, 583 "%s: spinning on %p held by %p", 584 __func__, m, owner); 585 KTR_STATE1(KTR_SCHED, "thread", 586 sched_tdname((struct thread *)tid), 587 "spinning", "lockname:\"%s\"", 588 m->lock_object.lo_name); 589 do { 590 lock_delay(&lda); 591 v = MTX_READ_VALUE(m); 592 owner = lv_mtx_owner(v); 593 } while (v != MTX_UNOWNED && TD_IS_RUNNING(owner)); 594 KTR_STATE0(KTR_SCHED, "thread", 595 sched_tdname((struct thread *)tid), 596 "running"); 597 continue; 598 } 599#endif 600 601 ts = turnstile_trywait(&m->lock_object); 602 v = MTX_READ_VALUE(m); 603retry_turnstile: 604 605 /* 606 * Check if the lock has been released while spinning for 607 * the turnstile chain lock. 608 */ 609 if (v == MTX_UNOWNED) { 610 turnstile_cancel(ts); 611 continue; 612 } 613 614#ifdef ADAPTIVE_MUTEXES 615 /* 616 * The current lock owner might have started executing 617 * on another CPU (or the lock could have changed 618 * owners) while we were waiting on the turnstile 619 * chain lock. If so, drop the turnstile lock and try 620 * again. 621 */ 622 owner = lv_mtx_owner(v); 623 if (TD_IS_RUNNING(owner)) { 624 turnstile_cancel(ts); 625 continue; 626 } 627#endif 628 629 /* 630 * If the mutex isn't already contested and a failure occurs 631 * setting the contested bit, the mutex was either released 632 * or the state of the MTX_RECURSED bit changed. 633 */ 634 if ((v & MTX_CONTESTED) == 0 && 635 !atomic_fcmpset_ptr(&m->mtx_lock, &v, v | MTX_CONTESTED)) { 636 goto retry_turnstile; 637 } 638 639 /* 640 * We definitely must sleep for this lock. 641 */ 642 mtx_assert(m, MA_NOTOWNED); 643 644 /* 645 * Block on the turnstile. 646 */ 647#ifdef KDTRACE_HOOKS 648 sleep_time -= lockstat_nsecs(&m->lock_object); 649#endif 650#ifndef ADAPTIVE_MUTEXES 651 owner = mtx_owner(m); 652#endif 653 MPASS(owner == mtx_owner(m)); 654 turnstile_wait(ts, owner, TS_EXCLUSIVE_QUEUE); 655#ifdef KDTRACE_HOOKS 656 sleep_time += lockstat_nsecs(&m->lock_object); 657 sleep_cnt++; 658#endif 659 v = MTX_READ_VALUE(m); 660 } 661#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 662 if (__predict_true(!doing_lockprof)) 663 return; 664#endif 665#ifdef KDTRACE_HOOKS 666 all_time += lockstat_nsecs(&m->lock_object); 667 if (sleep_time) 668 LOCKSTAT_RECORD1(adaptive__block, m, sleep_time); 669 670 /* 671 * Only record the loops spinning and not sleeping. 672 */ 673 if (lda.spin_cnt > sleep_cnt) 674 LOCKSTAT_RECORD1(adaptive__spin, m, all_time - sleep_time); 675out_lockstat: 676#endif 677 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, m, contested, 678 waittime, file, line); 679} 680 681#ifdef SMP 682/* 683 * _mtx_lock_spin_cookie: the tougher part of acquiring an MTX_SPIN lock. 684 * 685 * This is only called if we need to actually spin for the lock. Recursion 686 * is handled inline. 687 */ 688#if LOCK_DEBUG > 0 689void 690_mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts, 691 const char *file, int line) 692#else 693void 694_mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v) 695#endif 696{ 697 struct mtx *m; 698 struct lock_delay_arg lda; 699 uintptr_t tid; 700#ifdef LOCK_PROFILING 701 int contested = 0; 702 uint64_t waittime = 0; 703#endif 704#ifdef KDTRACE_HOOKS 705 int64_t spin_time = 0; 706#endif 707#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 708 int doing_lockprof = 0; 709#endif 710 711 tid = (uintptr_t)curthread; 712 m = mtxlock2mtx(c); 713 714#ifdef KDTRACE_HOOKS 715 if (LOCKSTAT_PROFILE_ENABLED(adaptive__acquire)) { 716 while (v == MTX_UNOWNED) { 717 if (_mtx_obtain_lock_fetch(m, &v, tid)) 718 goto out_lockstat; 719 } 720 doing_lockprof = 1; 721 spin_time -= lockstat_nsecs(&m->lock_object); 722 } 723#endif 724#ifdef LOCK_PROFILING 725 doing_lockprof = 1; 726#endif 727 728 if (__predict_false(v == MTX_UNOWNED)) 729 v = MTX_READ_VALUE(m); 730 731 if (__predict_false(v == tid)) { 732 m->mtx_recurse++; 733 return; 734 } 735 736 if (SCHEDULER_STOPPED()) 737 return; 738 739 lock_delay_arg_init(&lda, &mtx_spin_delay); 740 741 if (LOCK_LOG_TEST(&m->lock_object, opts)) 742 CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); 743 KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), 744 "spinning", "lockname:\"%s\"", m->lock_object.lo_name); 745 746#ifdef HWPMC_HOOKS 747 PMC_SOFT_CALL( , , lock, failed); 748#endif 749 lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); 750 751 for (;;) { 752 if (v == MTX_UNOWNED) { 753 if (_mtx_obtain_lock_fetch(m, &v, tid)) 754 break; 755 continue; 756 } 757 /* Give interrupts a chance while we spin. */ 758 spinlock_exit(); 759 do { 760 if (__predict_true(lda.spin_cnt < 10000000)) { 761 lock_delay(&lda); 762 } else { 763 _mtx_lock_indefinite_check(m, &lda); 764 } 765 v = MTX_READ_VALUE(m); 766 } while (v != MTX_UNOWNED); 767 spinlock_enter(); 768 } 769 770 if (LOCK_LOG_TEST(&m->lock_object, opts)) 771 CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); 772 KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), 773 "running"); 774 775#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 776 if (__predict_true(!doing_lockprof)) 777 return; 778#endif 779#ifdef KDTRACE_HOOKS 780 spin_time += lockstat_nsecs(&m->lock_object); 781 if (lda.spin_cnt != 0) 782 LOCKSTAT_RECORD1(spin__spin, m, spin_time); 783out_lockstat: 784#endif 785 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, 786 contested, waittime, file, line); 787} 788#endif /* SMP */ 789 790#ifdef INVARIANTS 791static void 792thread_lock_validate(struct mtx *m, int opts, const char *file, int line) 793{ 794 795 KASSERT(m->mtx_lock != MTX_DESTROYED, 796 ("thread_lock() of destroyed mutex @ %s:%d", file, line)); 797 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 798 ("thread_lock() of sleep mutex %s @ %s:%d", 799 m->lock_object.lo_name, file, line)); 800 if (mtx_owned(m)) 801 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, 802 ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", 803 m->lock_object.lo_name, file, line)); 804 WITNESS_CHECKORDER(&m->lock_object, 805 opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); 806} 807#else 808#define thread_lock_validate(m, opts, file, line) do { } while (0) 809#endif 810 811#ifndef LOCK_PROFILING 812#if LOCK_DEBUG > 0 813void 814_thread_lock(struct thread *td, int opts, const char *file, int line) 815#else 816void 817_thread_lock(struct thread *td) 818#endif 819{ 820 struct mtx *m; 821 uintptr_t tid, v; 822 823 tid = (uintptr_t)curthread; 824 825 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire))) 826 goto slowpath_noirq; 827 spinlock_enter(); 828 m = td->td_lock; 829 thread_lock_validate(m, 0, file, line); 830 v = MTX_READ_VALUE(m); 831 if (__predict_true(v == MTX_UNOWNED)) { 832 if (__predict_false(!_mtx_obtain_lock(m, tid))) 833 goto slowpath_unlocked; 834 } else if (v == tid) { 835 m->mtx_recurse++; 836 } else 837 goto slowpath_unlocked; 838 if (__predict_true(m == td->td_lock)) { 839 WITNESS_LOCK(&m->lock_object, LOP_EXCLUSIVE, file, line); 840 return; 841 } 842 MPASS(m->mtx_recurse == 0); 843 _mtx_release_lock_quick(m); 844slowpath_unlocked: 845 spinlock_exit(); 846slowpath_noirq: 847#if LOCK_DEBUG > 0 848 thread_lock_flags_(td, opts, file, line); 849#else 850 thread_lock_flags_(td, 0, 0, 0); 851#endif 852} 853#endif 854 855void 856thread_lock_flags_(struct thread *td, int opts, const char *file, int line) 857{ 858 struct mtx *m; 859 uintptr_t tid, v; 860 struct lock_delay_arg lda; 861#ifdef LOCK_PROFILING 862 int contested = 0; 863 uint64_t waittime = 0; 864#endif 865#ifdef KDTRACE_HOOKS 866 int64_t spin_time = 0; 867#endif 868#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 869 int doing_lockprof = 1; 870#endif 871 872 tid = (uintptr_t)curthread; 873 874 if (SCHEDULER_STOPPED()) { 875 /* 876 * Ensure that spinlock sections are balanced even when the 877 * scheduler is stopped, since we may otherwise inadvertently 878 * re-enable interrupts while dumping core. 879 */ 880 spinlock_enter(); 881 return; 882 } 883 884 lock_delay_arg_init(&lda, &mtx_spin_delay); 885 886#ifdef HWPMC_HOOKS 887 PMC_SOFT_CALL( , , lock, failed); 888#endif 889 890#ifdef LOCK_PROFILING 891 doing_lockprof = 1; 892#elif defined(KDTRACE_HOOKS) 893 doing_lockprof = lockstat_enabled; 894 if (__predict_false(doing_lockprof)) 895 spin_time -= lockstat_nsecs(&td->td_lock->lock_object); 896#endif 897 spinlock_enter(); 898 899 for (;;) { 900retry: 901 m = td->td_lock; 902 thread_lock_validate(m, opts, file, line); 903 v = MTX_READ_VALUE(m); 904 for (;;) { 905 if (v == MTX_UNOWNED) { 906 if (_mtx_obtain_lock_fetch(m, &v, tid)) 907 break; 908 continue; 909 } 910 if (v == tid) { 911 m->mtx_recurse++; 912 MPASS(m == td->td_lock); 913 break; 914 } 915 lock_profile_obtain_lock_failed(&m->lock_object, 916 &contested, &waittime); 917 /* Give interrupts a chance while we spin. */ 918 spinlock_exit(); 919 do { 920 if (__predict_true(lda.spin_cnt < 10000000)) { 921 lock_delay(&lda); 922 } else { 923 _mtx_lock_indefinite_check(m, &lda); 924 } 925 if (m != td->td_lock) { 926 spinlock_enter(); 927 goto retry; 928 } 929 v = MTX_READ_VALUE(m); 930 } while (v != MTX_UNOWNED); 931 spinlock_enter(); 932 } 933 if (m == td->td_lock) 934 break; 935 MPASS(m->mtx_recurse == 0); 936 _mtx_release_lock_quick(m); 937 } 938 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 939 line); 940 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 941 942#if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 943 if (__predict_true(!doing_lockprof)) 944 return; 945#endif 946#ifdef KDTRACE_HOOKS 947 spin_time += lockstat_nsecs(&m->lock_object); 948#endif 949 if (m->mtx_recurse == 0) 950 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, 951 contested, waittime, file, line); 952#ifdef KDTRACE_HOOKS 953 if (lda.spin_cnt != 0) 954 LOCKSTAT_RECORD1(thread__spin, m, spin_time); 955#endif 956} 957 958struct mtx * 959thread_lock_block(struct thread *td) 960{ 961 struct mtx *lock; 962 963 THREAD_LOCK_ASSERT(td, MA_OWNED); 964 lock = td->td_lock; 965 td->td_lock = &blocked_lock; 966 mtx_unlock_spin(lock); 967 968 return (lock); 969} 970 971void 972thread_lock_unblock(struct thread *td, struct mtx *new) 973{ 974 mtx_assert(new, MA_OWNED); 975 MPASS(td->td_lock == &blocked_lock); 976 atomic_store_rel_ptr((volatile void *)&td->td_lock, (uintptr_t)new); 977} 978 979void 980thread_lock_set(struct thread *td, struct mtx *new) 981{ 982 struct mtx *lock; 983 984 mtx_assert(new, MA_OWNED); 985 THREAD_LOCK_ASSERT(td, MA_OWNED); 986 lock = td->td_lock; 987 td->td_lock = new; 988 mtx_unlock_spin(lock); 989} 990 991/* 992 * __mtx_unlock_sleep: the tougher part of releasing an MTX_DEF lock. 993 * 994 * We are only called here if the lock is recursed, contested (i.e. we 995 * need to wake up a blocked thread) or lockstat probe is active. 996 */ 997#if LOCK_DEBUG > 0 998void 999__mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, 1000 const char *file, int line) 1001#else 1002void 1003__mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v) 1004#endif 1005{ 1006 struct mtx *m; 1007 struct turnstile *ts; 1008 uintptr_t tid; 1009 1010 if (SCHEDULER_STOPPED()) 1011 return; 1012 1013 tid = (uintptr_t)curthread; 1014 m = mtxlock2mtx(c); 1015 1016 if (__predict_false(v == tid)) 1017 v = MTX_READ_VALUE(m); 1018 1019 if (__predict_false(v & MTX_RECURSED)) { 1020 if (--(m->mtx_recurse) == 0) 1021 atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED); 1022 if (LOCK_LOG_TEST(&m->lock_object, opts)) 1023 CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p unrecurse", m); 1024 return; 1025 } 1026 1027 LOCKSTAT_PROFILE_RELEASE_LOCK(adaptive__release, m); 1028 if (v == tid && _mtx_release_lock(m, tid)) 1029 return; 1030 1031 /* 1032 * We have to lock the chain before the turnstile so this turnstile 1033 * can be removed from the hash list if it is empty. 1034 */ 1035 turnstile_chain_lock(&m->lock_object); 1036 _mtx_release_lock_quick(m); 1037 ts = turnstile_lookup(&m->lock_object); 1038 MPASS(ts != NULL); 1039 if (LOCK_LOG_TEST(&m->lock_object, opts)) 1040 CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m); 1041 turnstile_broadcast(ts, TS_EXCLUSIVE_QUEUE); 1042 1043 /* 1044 * This turnstile is now no longer associated with the mutex. We can 1045 * unlock the chain lock so a new turnstile may take it's place. 1046 */ 1047 turnstile_unpend(ts); 1048 turnstile_chain_unlock(&m->lock_object); 1049} 1050 1051/* 1052 * All the unlocking of MTX_SPIN locks is done inline. 1053 * See the __mtx_unlock_spin() macro for the details. 1054 */ 1055 1056/* 1057 * The backing function for the INVARIANTS-enabled mtx_assert() 1058 */ 1059#ifdef INVARIANT_SUPPORT 1060void 1061__mtx_assert(const volatile uintptr_t *c, int what, const char *file, int line) 1062{ 1063 const struct mtx *m; 1064 1065 if (panicstr != NULL || dumping || SCHEDULER_STOPPED()) 1066 return; 1067 1068 m = mtxlock2mtx(c); 1069 1070 switch (what) { 1071 case MA_OWNED: 1072 case MA_OWNED | MA_RECURSED: 1073 case MA_OWNED | MA_NOTRECURSED: 1074 if (!mtx_owned(m)) 1075 panic("mutex %s not owned at %s:%d", 1076 m->lock_object.lo_name, file, line); 1077 if (mtx_recursed(m)) { 1078 if ((what & MA_NOTRECURSED) != 0) 1079 panic("mutex %s recursed at %s:%d", 1080 m->lock_object.lo_name, file, line); 1081 } else if ((what & MA_RECURSED) != 0) { 1082 panic("mutex %s unrecursed at %s:%d", 1083 m->lock_object.lo_name, file, line); 1084 } 1085 break; 1086 case MA_NOTOWNED: 1087 if (mtx_owned(m)) 1088 panic("mutex %s owned at %s:%d", 1089 m->lock_object.lo_name, file, line); 1090 break; 1091 default: 1092 panic("unknown mtx_assert at %s:%d", file, line); 1093 } 1094} 1095#endif 1096 1097/* 1098 * General init routine used by the MTX_SYSINIT() macro. 1099 */ 1100void 1101mtx_sysinit(void *arg) 1102{ 1103 struct mtx_args *margs = arg; 1104 1105 mtx_init((struct mtx *)margs->ma_mtx, margs->ma_desc, NULL, 1106 margs->ma_opts); 1107} 1108 1109/* 1110 * Mutex initialization routine; initialize lock `m' of type contained in 1111 * `opts' with options contained in `opts' and name `name.' The optional 1112 * lock type `type' is used as a general lock category name for use with 1113 * witness. 1114 */ 1115void 1116_mtx_init(volatile uintptr_t *c, const char *name, const char *type, int opts) 1117{ 1118 struct mtx *m; 1119 struct lock_class *class; 1120 int flags; 1121 1122 m = mtxlock2mtx(c); 1123 1124 MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE | 1125 MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE | MTX_NEW)) == 0); 1126 ASSERT_ATOMIC_LOAD_PTR(m->mtx_lock, 1127 ("%s: mtx_lock not aligned for %s: %p", __func__, name, 1128 &m->mtx_lock)); 1129 1130 /* Determine lock class and lock flags. */ 1131 if (opts & MTX_SPIN) 1132 class = &lock_class_mtx_spin; 1133 else 1134 class = &lock_class_mtx_sleep; 1135 flags = 0; 1136 if (opts & MTX_QUIET) 1137 flags |= LO_QUIET; 1138 if (opts & MTX_RECURSE) 1139 flags |= LO_RECURSABLE; 1140 if ((opts & MTX_NOWITNESS) == 0) 1141 flags |= LO_WITNESS; 1142 if (opts & MTX_DUPOK) 1143 flags |= LO_DUPOK; 1144 if (opts & MTX_NOPROFILE) 1145 flags |= LO_NOPROFILE; 1146 if (opts & MTX_NEW) 1147 flags |= LO_NEW; 1148 1149 /* Initialize mutex. */ 1150 lock_init(&m->lock_object, class, name, type, flags); 1151 1152 m->mtx_lock = MTX_UNOWNED; 1153 m->mtx_recurse = 0; 1154} 1155 1156/* 1157 * Remove lock `m' from all_mtx queue. We don't allow MTX_QUIET to be 1158 * passed in as a flag here because if the corresponding mtx_init() was 1159 * called with MTX_QUIET set, then it will already be set in the mutex's 1160 * flags. 1161 */ 1162void 1163_mtx_destroy(volatile uintptr_t *c) 1164{ 1165 struct mtx *m; 1166 1167 m = mtxlock2mtx(c); 1168 1169 if (!mtx_owned(m)) 1170 MPASS(mtx_unowned(m)); 1171 else { 1172 MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0); 1173 1174 /* Perform the non-mtx related part of mtx_unlock_spin(). */ 1175 if (LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin) 1176 spinlock_exit(); 1177 else 1178 TD_LOCKS_DEC(curthread); 1179 1180 lock_profile_release_lock(&m->lock_object); 1181 /* Tell witness this isn't locked to make it happy. */ 1182 WITNESS_UNLOCK(&m->lock_object, LOP_EXCLUSIVE, __FILE__, 1183 __LINE__); 1184 } 1185 1186 m->mtx_lock = MTX_DESTROYED; 1187 lock_destroy(&m->lock_object); 1188} 1189 1190/* 1191 * Intialize the mutex code and system mutexes. This is called from the MD 1192 * startup code prior to mi_startup(). The per-CPU data space needs to be 1193 * setup before this is called. 1194 */ 1195void 1196mutex_init(void) 1197{ 1198 1199 /* Setup turnstiles so that sleep mutexes work. */ 1200 init_turnstiles(); 1201 1202 /* 1203 * Initialize mutexes. 1204 */ 1205 mtx_init(&Giant, "Giant", NULL, MTX_DEF | MTX_RECURSE); 1206 mtx_init(&blocked_lock, "blocked lock", NULL, MTX_SPIN); 1207 blocked_lock.mtx_lock = 0xdeadc0de; /* Always blocked. */ 1208 mtx_init(&proc0.p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK); 1209 mtx_init(&proc0.p_slock, "process slock", NULL, MTX_SPIN); 1210 mtx_init(&proc0.p_statmtx, "pstatl", NULL, MTX_SPIN); 1211 mtx_init(&proc0.p_itimmtx, "pitiml", NULL, MTX_SPIN); 1212 mtx_init(&proc0.p_profmtx, "pprofl", NULL, MTX_SPIN); 1213 mtx_init(&devmtx, "cdev", NULL, MTX_DEF); 1214 mtx_lock(&Giant); 1215} 1216 1217static void __noinline 1218_mtx_lock_indefinite_check(struct mtx *m, struct lock_delay_arg *ldap) 1219{ 1220 struct thread *td; 1221 1222 ldap->spin_cnt++; 1223 if (ldap->spin_cnt < 60000000 || kdb_active || panicstr != NULL) 1224 cpu_lock_delay(); 1225 else { 1226 td = mtx_owner(m); 1227 1228 /* If the mutex is unlocked, try again. */ 1229 if (td == NULL) 1230 return; 1231 1232 printf( "spin lock %p (%s) held by %p (tid %d) too long\n", 1233 m, m->lock_object.lo_name, td, td->td_tid); 1234#ifdef WITNESS 1235 witness_display_spinlock(&m->lock_object, td, printf); 1236#endif 1237 panic("spin lock held too long"); 1238 } 1239 cpu_spinwait(); 1240} 1241 1242void 1243mtx_spin_wait_unlocked(struct mtx *m) 1244{ 1245 struct lock_delay_arg lda; 1246 1247 KASSERT(m->mtx_lock != MTX_DESTROYED, 1248 ("%s() of destroyed mutex %p", __func__, m)); 1249 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 1250 ("%s() of sleep mutex %p (%s)", __func__, m, 1251 m->lock_object.lo_name)); 1252 KASSERT(!mtx_owned(m), ("%s() waiting on myself on lock %p (%s)", __func__, m, 1253 m->lock_object.lo_name)); 1254 1255 lda.spin_cnt = 0; 1256 1257 while (atomic_load_acq_ptr(&m->mtx_lock) != MTX_UNOWNED) { 1258 if (__predict_true(lda.spin_cnt < 10000000)) { 1259 cpu_spinwait(); 1260 lda.spin_cnt++; 1261 } else { 1262 _mtx_lock_indefinite_check(m, &lda); 1263 } 1264 } 1265} 1266 1267#ifdef DDB 1268void 1269db_show_mtx(const struct lock_object *lock) 1270{ 1271 struct thread *td; 1272 const struct mtx *m; 1273 1274 m = (const struct mtx *)lock; 1275 1276 db_printf(" flags: {"); 1277 if (LOCK_CLASS(lock) == &lock_class_mtx_spin) 1278 db_printf("SPIN"); 1279 else 1280 db_printf("DEF"); 1281 if (m->lock_object.lo_flags & LO_RECURSABLE) 1282 db_printf(", RECURSE"); 1283 if (m->lock_object.lo_flags & LO_DUPOK) 1284 db_printf(", DUPOK"); 1285 db_printf("}\n"); 1286 db_printf(" state: {"); 1287 if (mtx_unowned(m)) 1288 db_printf("UNOWNED"); 1289 else if (mtx_destroyed(m)) 1290 db_printf("DESTROYED"); 1291 else { 1292 db_printf("OWNED"); 1293 if (m->mtx_lock & MTX_CONTESTED) 1294 db_printf(", CONTESTED"); 1295 if (m->mtx_lock & MTX_RECURSED) 1296 db_printf(", RECURSED"); 1297 } 1298 db_printf("}\n"); 1299 if (!mtx_unowned(m) && !mtx_destroyed(m)) { 1300 td = mtx_owner(m); 1301 db_printf(" owner: %p (tid %d, pid %d, \"%s\")\n", td, 1302 td->td_tid, td->td_proc->p_pid, td->td_name); 1303 if (mtx_recursed(m)) 1304 db_printf(" recursed: %d\n", m->mtx_recurse); 1305 } 1306} 1307#endif 1308