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> 83 PMC_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 99 static void assert_mtx(const struct lock_object *lock, int what); 100 #ifdef DDB 101 static void db_show_mtx(const struct lock_object *lock); 102 #endif 103 static void lock_mtx(struct lock_object *lock, uintptr_t how); 104 static void lock_spin(struct lock_object *lock, uintptr_t how); 105 #ifdef KDTRACE_HOOKS 106 static int owner_mtx(const struct lock_object *lock, 107 struct thread **owner); 108 #endif 109 static uintptr_t unlock_mtx(struct lock_object *lock); 110 static uintptr_t unlock_spin(struct lock_object *lock); 111 112 /* 113 * Lock classes for sleep and spin mutexes. 114 */ 115 struct 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 }; 128 struct 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 143 static SYSCTL_NODE(_debug, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mtx debugging"); 144 145 static struct lock_delay_config __read_frequently mtx_delay; 146 147 SYSCTL_INT(_debug_mtx, OID_AUTO, delay_base, CTLFLAG_RW, &mtx_delay.base, 148 0, ""); 149 SYSCTL_INT(_debug_mtx, OID_AUTO, delay_max, CTLFLAG_RW, &mtx_delay.max, 150 0, ""); 151 152 LOCK_DELAY_SYSINIT_DEFAULT(mtx_delay); 153 #endif 154 155 static SYSCTL_NODE(_debug, OID_AUTO, mtx_spin, CTLFLAG_RD, NULL, 156 "mtx spin debugging"); 157 158 static struct lock_delay_config __read_frequently mtx_spin_delay; 159 160 SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_base, CTLFLAG_RW, 161 &mtx_spin_delay.base, 0, ""); 162 SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_max, CTLFLAG_RW, 163 &mtx_spin_delay.max, 0, ""); 164 165 LOCK_DELAY_SYSINIT_DEFAULT(mtx_spin_delay); 166 167 /* 168 * System-wide mutexes 169 */ 170 struct mtx blocked_lock; 171 struct mtx __exclusive_cache_line Giant; 172 173 static void _mtx_lock_indefinite_check(struct mtx *, struct lock_delay_arg *); 174 175 void 176 assert_mtx(const struct lock_object *lock, int what) 177 { 178 179 mtx_assert((const struct mtx *)lock, what); 180 } 181 182 void 183 lock_mtx(struct lock_object *lock, uintptr_t how) 184 { 185 186 mtx_lock((struct mtx *)lock); 187 } 188 189 void 190 lock_spin(struct lock_object *lock, uintptr_t how) 191 { 192 193 panic("spin locks can only use msleep_spin"); 194 } 195 196 uintptr_t 197 unlock_mtx(struct lock_object *lock) 198 { 199 struct mtx *m; 200 201 m = (struct mtx *)lock; 202 mtx_assert(m, MA_OWNED | MA_NOTRECURSED); 203 mtx_unlock(m); 204 return (0); 205 } 206 207 uintptr_t 208 unlock_spin(struct lock_object *lock) 209 { 210 211 panic("spin locks can only use msleep_spin"); 212 } 213 214 #ifdef KDTRACE_HOOKS 215 int 216 owner_mtx(const struct lock_object *lock, struct thread **owner) 217 { 218 const struct mtx *m; 219 uintptr_t x; 220 221 m = (const struct mtx *)lock; 222 x = m->mtx_lock; 223 *owner = (struct thread *)(x & ~MTX_FLAGMASK); 224 return (*owner != NULL); 225 } 226 #endif 227 228 /* 229 * Function versions of the inlined __mtx_* macros. These are used by 230 * modules and can also be called from assembly language if needed. 231 */ 232 void 233 __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line) 234 { 235 struct mtx *m; 236 uintptr_t tid, v; 237 238 m = mtxlock2mtx(c); 239 240 KASSERT(kdb_active != 0 || SCHEDULER_STOPPED() || 241 !TD_IS_IDLETHREAD(curthread), 242 ("mtx_lock() by idle thread %p on sleep mutex %s @ %s:%d", 243 curthread, m->lock_object.lo_name, file, line)); 244 KASSERT(m->mtx_lock != MTX_DESTROYED, 245 ("mtx_lock() of destroyed mutex @ %s:%d", file, line)); 246 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 247 ("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 248 file, line)); 249 WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) | 250 LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); 251 252 tid = (uintptr_t)curthread; 253 v = MTX_UNOWNED; 254 if (!_mtx_obtain_lock_fetch(m, &v, tid)) 255 _mtx_lock_sleep(m, v, opts, file, line); 256 else 257 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, 258 m, 0, 0, file, line); 259 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 260 line); 261 WITNESS_LOCK(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_EXCLUSIVE, 262 file, line); 263 TD_LOCKS_INC(curthread); 264 } 265 266 void 267 __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line) 268 { 269 struct mtx *m; 270 271 m = mtxlock2mtx(c); 272 273 KASSERT(m->mtx_lock != MTX_DESTROYED, 274 ("mtx_unlock() of destroyed mutex @ %s:%d", file, line)); 275 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 276 ("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 277 file, line)); 278 WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 279 LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, 280 line); 281 mtx_assert(m, MA_OWNED); 282 283 #ifdef LOCK_PROFILING 284 __mtx_unlock_sleep(c, (uintptr_t)curthread, opts, file, line); 285 #else 286 __mtx_unlock(m, curthread, opts, file, line); 287 #endif 288 TD_LOCKS_DEC(curthread); 289 } 290 291 void 292 __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 293 int line) 294 { 295 struct mtx *m; 296 #ifdef SMP 297 uintptr_t tid, v; 298 #endif 299 300 m = mtxlock2mtx(c); 301 302 KASSERT(m->mtx_lock != MTX_DESTROYED, 303 ("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line)); 304 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 305 ("mtx_lock_spin() of sleep mutex %s @ %s:%d", 306 m->lock_object.lo_name, file, line)); 307 if (mtx_owned(m)) 308 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 309 (opts & MTX_RECURSE) != 0, 310 ("mtx_lock_spin: recursed on non-recursive mutex %s @ %s:%d\n", 311 m->lock_object.lo_name, file, line)); 312 opts &= ~MTX_RECURSE; 313 WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, 314 file, line, NULL); 315 #ifdef SMP 316 spinlock_enter(); 317 tid = (uintptr_t)curthread; 318 v = MTX_UNOWNED; 319 if (!_mtx_obtain_lock_fetch(m, &v, tid)) 320 _mtx_lock_spin(m, v, opts, file, line); 321 else 322 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, 323 m, 0, 0, file, line); 324 #else 325 __mtx_lock_spin(m, curthread, opts, file, line); 326 #endif 327 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 328 line); 329 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 330 } 331 332 int 333 __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 334 int line) 335 { 336 struct mtx *m; 337 338 if (SCHEDULER_STOPPED()) 339 return (1); 340 341 m = mtxlock2mtx(c); 342 343 KASSERT(m->mtx_lock != MTX_DESTROYED, 344 ("mtx_trylock_spin() of destroyed mutex @ %s:%d", file, line)); 345 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 346 ("mtx_trylock_spin() of sleep mutex %s @ %s:%d", 347 m->lock_object.lo_name, file, line)); 348 KASSERT((opts & MTX_RECURSE) == 0, 349 ("mtx_trylock_spin: unsupp. opt MTX_RECURSE on mutex %s @ %s:%d\n", 350 m->lock_object.lo_name, file, line)); 351 if (__mtx_trylock_spin(m, curthread, opts, file, line)) { 352 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 1, file, line); 353 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 354 return (1); 355 } 356 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 0, file, line); 357 return (0); 358 } 359 360 void 361 __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file, 362 int line) 363 { 364 struct mtx *m; 365 366 m = mtxlock2mtx(c); 367 368 KASSERT(m->mtx_lock != MTX_DESTROYED, 369 ("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line)); 370 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 371 ("mtx_unlock_spin() of sleep mutex %s @ %s:%d", 372 m->lock_object.lo_name, file, line)); 373 WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 374 LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, 375 line); 376 mtx_assert(m, MA_OWNED); 377 378 __mtx_unlock_spin(m); 379 } 380 381 /* 382 * The important part of mtx_trylock{,_flags}() 383 * Tries to acquire lock `m.' If this function is called on a mutex that 384 * is already owned, it will recursively acquire the lock. 385 */ 386 int 387 _mtx_trylock_flags_int(struct mtx *m, int opts LOCK_FILE_LINE_ARG_DEF) 388 { 389 struct thread *td; 390 uintptr_t tid, v; 391 #ifdef LOCK_PROFILING 392 uint64_t waittime = 0; 393 int contested = 0; 394 #endif 395 int rval; 396 bool recursed; 397 398 td = curthread; 399 tid = (uintptr_t)td; 400 if (SCHEDULER_STOPPED_TD(td)) 401 return (1); 402 403 KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td), 404 ("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d", 405 curthread, m->lock_object.lo_name, file, line)); 406 KASSERT(m->mtx_lock != MTX_DESTROYED, 407 ("mtx_trylock() of destroyed mutex @ %s:%d", file, line)); 408 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, 409 ("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, 410 file, line)); 411 412 rval = 1; 413 recursed = false; 414 v = MTX_UNOWNED; 415 for (;;) { 416 if (_mtx_obtain_lock_fetch(m, &v, tid)) 417 break; 418 if (v == MTX_UNOWNED) 419 continue; 420 if (v == tid && 421 ((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 422 (opts & MTX_RECURSE) != 0)) { 423 m->mtx_recurse++; 424 atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); 425 recursed = true; 426 break; 427 } 428 rval = 0; 429 break; 430 } 431 432 opts &= ~MTX_RECURSE; 433 434 LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line); 435 if (rval) { 436 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK, 437 file, line); 438 TD_LOCKS_INC(curthread); 439 if (!recursed) 440 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, 441 m, contested, waittime, file, line); 442 } 443 444 return (rval); 445 } 446 447 int 448 _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, int line) 449 { 450 struct mtx *m; 451 452 m = mtxlock2mtx(c); 453 return (_mtx_trylock_flags_int(m, opts LOCK_FILE_LINE_ARG)); 454 } 455 456 /* 457 * __mtx_lock_sleep: the tougher part of acquiring an MTX_DEF lock. 458 * 459 * We call this if the lock is either contested (i.e. we need to go to 460 * sleep waiting for it), or if we need to recurse on it. 461 */ 462 #if LOCK_DEBUG > 0 463 void 464 __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, const char *file, 465 int line) 466 #else 467 void 468 __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v) 469 #endif 470 { 471 struct thread *td; 472 struct mtx *m; 473 struct turnstile *ts; 474 uintptr_t tid; 475 struct thread *owner; 476 #ifdef KTR 477 int cont_logged = 0; 478 #endif 479 #ifdef LOCK_PROFILING 480 int contested = 0; 481 uint64_t waittime = 0; 482 #endif 483 #if defined(ADAPTIVE_MUTEXES) || defined(KDTRACE_HOOKS) 484 struct lock_delay_arg lda; 485 #endif 486 #ifdef KDTRACE_HOOKS 487 u_int sleep_cnt = 0; 488 int64_t sleep_time = 0; 489 int64_t all_time = 0; 490 #endif 491 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 492 int doing_lockprof; 493 #endif 494 td = curthread; 495 tid = (uintptr_t)td; 496 if (SCHEDULER_STOPPED_TD(td)) 497 return; 498 499 #if defined(ADAPTIVE_MUTEXES) 500 lock_delay_arg_init(&lda, &mtx_delay); 501 #elif defined(KDTRACE_HOOKS) 502 lock_delay_arg_init(&lda, NULL); 503 #endif 504 m = mtxlock2mtx(c); 505 if (__predict_false(v == MTX_UNOWNED)) 506 v = MTX_READ_VALUE(m); 507 508 if (__predict_false(lv_mtx_owner(v) == td)) { 509 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || 510 (opts & MTX_RECURSE) != 0, 511 ("_mtx_lock_sleep: recursed on non-recursive mutex %s @ %s:%d\n", 512 m->lock_object.lo_name, file, line)); 513 #if LOCK_DEBUG > 0 514 opts &= ~MTX_RECURSE; 515 #endif 516 m->mtx_recurse++; 517 atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); 518 if (LOCK_LOG_TEST(&m->lock_object, opts)) 519 CTR1(KTR_LOCK, "_mtx_lock_sleep: %p recursing", m); 520 return; 521 } 522 #if LOCK_DEBUG > 0 523 opts &= ~MTX_RECURSE; 524 #endif 525 526 #ifdef HWPMC_HOOKS 527 PMC_SOFT_CALL( , , lock, failed); 528 #endif 529 lock_profile_obtain_lock_failed(&m->lock_object, 530 &contested, &waittime); 531 if (LOCK_LOG_TEST(&m->lock_object, opts)) 532 CTR4(KTR_LOCK, 533 "_mtx_lock_sleep: %s contested (lock=%p) at %s:%d", 534 m->lock_object.lo_name, (void *)m->mtx_lock, file, line); 535 #ifdef LOCK_PROFILING 536 doing_lockprof = 1; 537 #elif defined(KDTRACE_HOOKS) 538 doing_lockprof = lockstat_enabled; 539 if (__predict_false(doing_lockprof)) 540 all_time -= lockstat_nsecs(&m->lock_object); 541 #endif 542 543 for (;;) { 544 if (v == MTX_UNOWNED) { 545 if (_mtx_obtain_lock_fetch(m, &v, tid)) 546 break; 547 continue; 548 } 549 #ifdef KDTRACE_HOOKS 550 lda.spin_cnt++; 551 #endif 552 #ifdef ADAPTIVE_MUTEXES 553 /* 554 * If the owner is running on another CPU, spin until the 555 * owner stops running or the state of the lock changes. 556 */ 557 owner = lv_mtx_owner(v); 558 if (TD_IS_RUNNING(owner)) { 559 if (LOCK_LOG_TEST(&m->lock_object, 0)) 560 CTR3(KTR_LOCK, 561 "%s: spinning on %p held by %p", 562 __func__, m, owner); 563 KTR_STATE1(KTR_SCHED, "thread", 564 sched_tdname((struct thread *)tid), 565 "spinning", "lockname:\"%s\"", 566 m->lock_object.lo_name); 567 do { 568 lock_delay(&lda); 569 v = MTX_READ_VALUE(m); 570 owner = lv_mtx_owner(v); 571 } while (v != MTX_UNOWNED && TD_IS_RUNNING(owner)); 572 KTR_STATE0(KTR_SCHED, "thread", 573 sched_tdname((struct thread *)tid), 574 "running"); 575 continue; 576 } 577 #endif 578 579 ts = turnstile_trywait(&m->lock_object); 580 v = MTX_READ_VALUE(m); 581 retry_turnstile: 582 583 /* 584 * Check if the lock has been released while spinning for 585 * the turnstile chain lock. 586 */ 587 if (v == MTX_UNOWNED) { 588 turnstile_cancel(ts); 589 continue; 590 } 591 592 #ifdef ADAPTIVE_MUTEXES 593 /* 594 * The current lock owner might have started executing 595 * on another CPU (or the lock could have changed 596 * owners) while we were waiting on the turnstile 597 * chain lock. If so, drop the turnstile lock and try 598 * again. 599 */ 600 owner = lv_mtx_owner(v); 601 if (TD_IS_RUNNING(owner)) { 602 turnstile_cancel(ts); 603 continue; 604 } 605 #endif 606 607 /* 608 * If the mutex isn't already contested and a failure occurs 609 * setting the contested bit, the mutex was either released 610 * or the state of the MTX_RECURSED bit changed. 611 */ 612 if ((v & MTX_CONTESTED) == 0 && 613 !atomic_fcmpset_ptr(&m->mtx_lock, &v, v | MTX_CONTESTED)) { 614 goto retry_turnstile; 615 } 616 617 /* 618 * We definitely must sleep for this lock. 619 */ 620 mtx_assert(m, MA_NOTOWNED); 621 622 #ifdef KTR 623 if (!cont_logged) { 624 CTR6(KTR_CONTENTION, 625 "contention: %p at %s:%d wants %s, taken by %s:%d", 626 (void *)tid, file, line, m->lock_object.lo_name, 627 WITNESS_FILE(&m->lock_object), 628 WITNESS_LINE(&m->lock_object)); 629 cont_logged = 1; 630 } 631 #endif 632 633 /* 634 * Block on the turnstile. 635 */ 636 #ifdef KDTRACE_HOOKS 637 sleep_time -= lockstat_nsecs(&m->lock_object); 638 #endif 639 #ifndef ADAPTIVE_MUTEXES 640 owner = mtx_owner(m); 641 #endif 642 MPASS(owner == mtx_owner(m)); 643 turnstile_wait(ts, owner, TS_EXCLUSIVE_QUEUE); 644 #ifdef KDTRACE_HOOKS 645 sleep_time += lockstat_nsecs(&m->lock_object); 646 sleep_cnt++; 647 #endif 648 v = MTX_READ_VALUE(m); 649 } 650 #ifdef KTR 651 if (cont_logged) { 652 CTR4(KTR_CONTENTION, 653 "contention end: %s acquired by %p at %s:%d", 654 m->lock_object.lo_name, (void *)tid, file, line); 655 } 656 #endif 657 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 658 if (__predict_true(!doing_lockprof)) 659 return; 660 #endif 661 #ifdef KDTRACE_HOOKS 662 all_time += lockstat_nsecs(&m->lock_object); 663 #endif 664 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, m, contested, 665 waittime, file, line); 666 #ifdef KDTRACE_HOOKS 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); 675 #endif 676 } 677 678 #ifdef SMP 679 /* 680 * _mtx_lock_spin_cookie: the tougher part of acquiring an MTX_SPIN lock. 681 * 682 * This is only called if we need to actually spin for the lock. Recursion 683 * is handled inline. 684 */ 685 #if LOCK_DEBUG > 0 686 void 687 _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, int opts, 688 const char *file, int line) 689 #else 690 void 691 _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v) 692 #endif 693 { 694 struct mtx *m; 695 struct lock_delay_arg lda; 696 uintptr_t tid; 697 #ifdef LOCK_PROFILING 698 int contested = 0; 699 uint64_t waittime = 0; 700 #endif 701 #ifdef KDTRACE_HOOKS 702 int64_t spin_time = 0; 703 #endif 704 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 705 int doing_lockprof; 706 #endif 707 708 tid = (uintptr_t)curthread; 709 m = mtxlock2mtx(c); 710 711 if (__predict_false(v == MTX_UNOWNED)) 712 v = MTX_READ_VALUE(m); 713 714 if (__predict_false(v == tid)) { 715 m->mtx_recurse++; 716 return; 717 } 718 719 if (SCHEDULER_STOPPED()) 720 return; 721 722 lock_delay_arg_init(&lda, &mtx_spin_delay); 723 724 if (LOCK_LOG_TEST(&m->lock_object, opts)) 725 CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); 726 KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), 727 "spinning", "lockname:\"%s\"", m->lock_object.lo_name); 728 729 #ifdef HWPMC_HOOKS 730 PMC_SOFT_CALL( , , lock, failed); 731 #endif 732 lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); 733 #ifdef LOCK_PROFILING 734 doing_lockprof = 1; 735 #elif defined(KDTRACE_HOOKS) 736 doing_lockprof = lockstat_enabled; 737 if (__predict_false(doing_lockprof)) 738 spin_time -= lockstat_nsecs(&m->lock_object); 739 #endif 740 for (;;) { 741 if (v == MTX_UNOWNED) { 742 if (_mtx_obtain_lock_fetch(m, &v, tid)) 743 break; 744 continue; 745 } 746 /* Give interrupts a chance while we spin. */ 747 spinlock_exit(); 748 do { 749 if (__predict_true(lda.spin_cnt < 10000000)) { 750 lock_delay(&lda); 751 } else { 752 _mtx_lock_indefinite_check(m, &lda); 753 } 754 v = MTX_READ_VALUE(m); 755 } while (v != MTX_UNOWNED); 756 spinlock_enter(); 757 } 758 759 if (LOCK_LOG_TEST(&m->lock_object, opts)) 760 CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); 761 KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), 762 "running"); 763 764 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 765 if (__predict_true(!doing_lockprof)) 766 return; 767 #endif 768 #ifdef KDTRACE_HOOKS 769 spin_time += lockstat_nsecs(&m->lock_object); 770 #endif 771 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, 772 contested, waittime, file, line); 773 #ifdef KDTRACE_HOOKS 774 if (lda.spin_cnt != 0) 775 LOCKSTAT_RECORD1(spin__spin, m, spin_time); 776 #endif 777 } 778 #endif /* SMP */ 779 780 #ifdef INVARIANTS 781 static void 782 thread_lock_validate(struct mtx *m, int opts, const char *file, int line) 783 { 784 785 KASSERT(m->mtx_lock != MTX_DESTROYED, 786 ("thread_lock() of destroyed mutex @ %s:%d", file, line)); 787 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 788 ("thread_lock() of sleep mutex %s @ %s:%d", 789 m->lock_object.lo_name, file, line)); 790 if (mtx_owned(m)) 791 KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, 792 ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", 793 m->lock_object.lo_name, file, line)); 794 WITNESS_CHECKORDER(&m->lock_object, 795 opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); 796 } 797 #else 798 #define thread_lock_validate(m, opts, file, line) do { } while (0) 799 #endif 800 801 #ifndef LOCK_PROFILING 802 #if LOCK_DEBUG > 0 803 void 804 _thread_lock(struct thread *td, int opts, const char *file, int line) 805 #else 806 void 807 _thread_lock(struct thread *td) 808 #endif 809 { 810 struct mtx *m; 811 uintptr_t tid, v; 812 813 tid = (uintptr_t)curthread; 814 815 if (__predict_false(LOCKSTAT_PROFILE_ENABLED(spin__acquire))) 816 goto slowpath_noirq; 817 spinlock_enter(); 818 m = td->td_lock; 819 thread_lock_validate(m, 0, file, line); 820 v = MTX_READ_VALUE(m); 821 if (__predict_true(v == MTX_UNOWNED)) { 822 if (__predict_false(!_mtx_obtain_lock(m, tid))) 823 goto slowpath_unlocked; 824 } else if (v == tid) { 825 m->mtx_recurse++; 826 } else 827 goto slowpath_unlocked; 828 if (__predict_true(m == td->td_lock)) { 829 WITNESS_LOCK(&m->lock_object, LOP_EXCLUSIVE, file, line); 830 return; 831 } 832 MPASS(m->mtx_recurse == 0); 833 _mtx_release_lock_quick(m); 834 slowpath_unlocked: 835 spinlock_exit(); 836 slowpath_noirq: 837 #if LOCK_DEBUG > 0 838 thread_lock_flags_(td, opts, file, line); 839 #else 840 thread_lock_flags_(td, 0, 0, 0); 841 #endif 842 } 843 #endif 844 845 void 846 thread_lock_flags_(struct thread *td, int opts, const char *file, int line) 847 { 848 struct mtx *m; 849 uintptr_t tid, v; 850 struct lock_delay_arg lda; 851 #ifdef LOCK_PROFILING 852 int contested = 0; 853 uint64_t waittime = 0; 854 #endif 855 #ifdef KDTRACE_HOOKS 856 int64_t spin_time = 0; 857 #endif 858 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 859 int doing_lockprof = 1; 860 #endif 861 862 tid = (uintptr_t)curthread; 863 864 if (SCHEDULER_STOPPED()) { 865 /* 866 * Ensure that spinlock sections are balanced even when the 867 * scheduler is stopped, since we may otherwise inadvertently 868 * re-enable interrupts while dumping core. 869 */ 870 spinlock_enter(); 871 return; 872 } 873 874 lock_delay_arg_init(&lda, &mtx_spin_delay); 875 876 #ifdef HWPMC_HOOKS 877 PMC_SOFT_CALL( , , lock, failed); 878 #endif 879 880 #ifdef LOCK_PROFILING 881 doing_lockprof = 1; 882 #elif defined(KDTRACE_HOOKS) 883 doing_lockprof = lockstat_enabled; 884 if (__predict_false(doing_lockprof)) 885 spin_time -= lockstat_nsecs(&td->td_lock->lock_object); 886 #endif 887 spinlock_enter(); 888 889 for (;;) { 890 retry: 891 m = td->td_lock; 892 thread_lock_validate(m, opts, file, line); 893 v = MTX_READ_VALUE(m); 894 for (;;) { 895 if (v == MTX_UNOWNED) { 896 if (_mtx_obtain_lock_fetch(m, &v, tid)) 897 break; 898 continue; 899 } 900 if (v == tid) { 901 m->mtx_recurse++; 902 MPASS(m == td->td_lock); 903 break; 904 } 905 lock_profile_obtain_lock_failed(&m->lock_object, 906 &contested, &waittime); 907 /* Give interrupts a chance while we spin. */ 908 spinlock_exit(); 909 do { 910 if (__predict_true(lda.spin_cnt < 10000000)) { 911 lock_delay(&lda); 912 } else { 913 _mtx_lock_indefinite_check(m, &lda); 914 } 915 if (m != td->td_lock) { 916 spinlock_enter(); 917 goto retry; 918 } 919 v = MTX_READ_VALUE(m); 920 } while (v != MTX_UNOWNED); 921 spinlock_enter(); 922 } 923 if (m == td->td_lock) 924 break; 925 MPASS(m->mtx_recurse == 0); 926 _mtx_release_lock_quick(m); 927 } 928 LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, 929 line); 930 WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); 931 932 #if defined(KDTRACE_HOOKS) || defined(LOCK_PROFILING) 933 if (__predict_true(!doing_lockprof)) 934 return; 935 #endif 936 #ifdef KDTRACE_HOOKS 937 spin_time += lockstat_nsecs(&m->lock_object); 938 #endif 939 if (m->mtx_recurse == 0) 940 LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, 941 contested, waittime, file, line); 942 #ifdef KDTRACE_HOOKS 943 if (lda.spin_cnt != 0) 944 LOCKSTAT_RECORD1(thread__spin, m, spin_time); 945 #endif 946 } 947 948 struct mtx * 949 thread_lock_block(struct thread *td) 950 { 951 struct mtx *lock; 952 953 THREAD_LOCK_ASSERT(td, MA_OWNED); 954 lock = td->td_lock; 955 td->td_lock = &blocked_lock; 956 mtx_unlock_spin(lock); 957 958 return (lock); 959 } 960 961 void 962 thread_lock_unblock(struct thread *td, struct mtx *new) 963 { 964 mtx_assert(new, MA_OWNED); 965 MPASS(td->td_lock == &blocked_lock); 966 atomic_store_rel_ptr((volatile void *)&td->td_lock, (uintptr_t)new); 967 } 968 969 void 970 thread_lock_set(struct thread *td, struct mtx *new) 971 { 972 struct mtx *lock; 973 974 mtx_assert(new, MA_OWNED); 975 THREAD_LOCK_ASSERT(td, MA_OWNED); 976 lock = td->td_lock; 977 td->td_lock = new; 978 mtx_unlock_spin(lock); 979 } 980 981 /* 982 * __mtx_unlock_sleep: the tougher part of releasing an MTX_DEF lock. 983 * 984 * We are only called here if the lock is recursed, contested (i.e. we 985 * need to wake up a blocked thread) or lockstat probe is active. 986 */ 987 #if LOCK_DEBUG > 0 988 void 989 __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v, int opts, 990 const char *file, int line) 991 #else 992 void 993 __mtx_unlock_sleep(volatile uintptr_t *c, uintptr_t v) 994 #endif 995 { 996 struct mtx *m; 997 struct turnstile *ts; 998 uintptr_t tid; 999 1000 if (SCHEDULER_STOPPED()) 1001 return; 1002 1003 tid = (uintptr_t)curthread; 1004 m = mtxlock2mtx(c); 1005 1006 if (__predict_false(v == tid)) 1007 v = MTX_READ_VALUE(m); 1008 1009 if (__predict_false(v & MTX_RECURSED)) { 1010 if (--(m->mtx_recurse) == 0) 1011 atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED); 1012 if (LOCK_LOG_TEST(&m->lock_object, opts)) 1013 CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p unrecurse", m); 1014 return; 1015 } 1016 1017 LOCKSTAT_PROFILE_RELEASE_LOCK(adaptive__release, m); 1018 if (v == tid && _mtx_release_lock(m, tid)) 1019 return; 1020 1021 /* 1022 * We have to lock the chain before the turnstile so this turnstile 1023 * can be removed from the hash list if it is empty. 1024 */ 1025 turnstile_chain_lock(&m->lock_object); 1026 _mtx_release_lock_quick(m); 1027 ts = turnstile_lookup(&m->lock_object); 1028 MPASS(ts != NULL); 1029 if (LOCK_LOG_TEST(&m->lock_object, opts)) 1030 CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m); 1031 turnstile_broadcast(ts, TS_EXCLUSIVE_QUEUE); 1032 1033 /* 1034 * This turnstile is now no longer associated with the mutex. We can 1035 * unlock the chain lock so a new turnstile may take it's place. 1036 */ 1037 turnstile_unpend(ts, TS_EXCLUSIVE_LOCK); 1038 turnstile_chain_unlock(&m->lock_object); 1039 } 1040 1041 /* 1042 * All the unlocking of MTX_SPIN locks is done inline. 1043 * See the __mtx_unlock_spin() macro for the details. 1044 */ 1045 1046 /* 1047 * The backing function for the INVARIANTS-enabled mtx_assert() 1048 */ 1049 #ifdef INVARIANT_SUPPORT 1050 void 1051 __mtx_assert(const volatile uintptr_t *c, int what, const char *file, int line) 1052 { 1053 const struct mtx *m; 1054 1055 if (panicstr != NULL || dumping || SCHEDULER_STOPPED()) 1056 return; 1057 1058 m = mtxlock2mtx(c); 1059 1060 switch (what) { 1061 case MA_OWNED: 1062 case MA_OWNED | MA_RECURSED: 1063 case MA_OWNED | MA_NOTRECURSED: 1064 if (!mtx_owned(m)) 1065 panic("mutex %s not owned at %s:%d", 1066 m->lock_object.lo_name, file, line); 1067 if (mtx_recursed(m)) { 1068 if ((what & MA_NOTRECURSED) != 0) 1069 panic("mutex %s recursed at %s:%d", 1070 m->lock_object.lo_name, file, line); 1071 } else if ((what & MA_RECURSED) != 0) { 1072 panic("mutex %s unrecursed at %s:%d", 1073 m->lock_object.lo_name, file, line); 1074 } 1075 break; 1076 case MA_NOTOWNED: 1077 if (mtx_owned(m)) 1078 panic("mutex %s owned at %s:%d", 1079 m->lock_object.lo_name, file, line); 1080 break; 1081 default: 1082 panic("unknown mtx_assert at %s:%d", file, line); 1083 } 1084 } 1085 #endif 1086 1087 /* 1088 * General init routine used by the MTX_SYSINIT() macro. 1089 */ 1090 void 1091 mtx_sysinit(void *arg) 1092 { 1093 struct mtx_args *margs = arg; 1094 1095 mtx_init((struct mtx *)margs->ma_mtx, margs->ma_desc, NULL, 1096 margs->ma_opts); 1097 } 1098 1099 /* 1100 * Mutex initialization routine; initialize lock `m' of type contained in 1101 * `opts' with options contained in `opts' and name `name.' The optional 1102 * lock type `type' is used as a general lock category name for use with 1103 * witness. 1104 */ 1105 void 1106 _mtx_init(volatile uintptr_t *c, const char *name, const char *type, int opts) 1107 { 1108 struct mtx *m; 1109 struct lock_class *class; 1110 int flags; 1111 1112 m = mtxlock2mtx(c); 1113 1114 MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE | 1115 MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE | MTX_NEW)) == 0); 1116 ASSERT_ATOMIC_LOAD_PTR(m->mtx_lock, 1117 ("%s: mtx_lock not aligned for %s: %p", __func__, name, 1118 &m->mtx_lock)); 1119 1120 /* Determine lock class and lock flags. */ 1121 if (opts & MTX_SPIN) 1122 class = &lock_class_mtx_spin; 1123 else 1124 class = &lock_class_mtx_sleep; 1125 flags = 0; 1126 if (opts & MTX_QUIET) 1127 flags |= LO_QUIET; 1128 if (opts & MTX_RECURSE) 1129 flags |= LO_RECURSABLE; 1130 if ((opts & MTX_NOWITNESS) == 0) 1131 flags |= LO_WITNESS; 1132 if (opts & MTX_DUPOK) 1133 flags |= LO_DUPOK; 1134 if (opts & MTX_NOPROFILE) 1135 flags |= LO_NOPROFILE; 1136 if (opts & MTX_NEW) 1137 flags |= LO_NEW; 1138 1139 /* Initialize mutex. */ 1140 lock_init(&m->lock_object, class, name, type, flags); 1141 1142 m->mtx_lock = MTX_UNOWNED; 1143 m->mtx_recurse = 0; 1144 } 1145 1146 /* 1147 * Remove lock `m' from all_mtx queue. We don't allow MTX_QUIET to be 1148 * passed in as a flag here because if the corresponding mtx_init() was 1149 * called with MTX_QUIET set, then it will already be set in the mutex's 1150 * flags. 1151 */ 1152 void 1153 _mtx_destroy(volatile uintptr_t *c) 1154 { 1155 struct mtx *m; 1156 1157 m = mtxlock2mtx(c); 1158 1159 if (!mtx_owned(m)) 1160 MPASS(mtx_unowned(m)); 1161 else { 1162 MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0); 1163 1164 /* Perform the non-mtx related part of mtx_unlock_spin(). */ 1165 if (LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin) 1166 spinlock_exit(); 1167 else 1168 TD_LOCKS_DEC(curthread); 1169 1170 lock_profile_release_lock(&m->lock_object); 1171 /* Tell witness this isn't locked to make it happy. */ 1172 WITNESS_UNLOCK(&m->lock_object, LOP_EXCLUSIVE, __FILE__, 1173 __LINE__); 1174 } 1175 1176 m->mtx_lock = MTX_DESTROYED; 1177 lock_destroy(&m->lock_object); 1178 } 1179 1180 /* 1181 * Intialize the mutex code and system mutexes. This is called from the MD 1182 * startup code prior to mi_startup(). The per-CPU data space needs to be 1183 * setup before this is called. 1184 */ 1185 void 1186 mutex_init(void) 1187 { 1188 1189 /* Setup turnstiles so that sleep mutexes work. */ 1190 init_turnstiles(); 1191 1192 /* 1193 * Initialize mutexes. 1194 */ 1195 mtx_init(&Giant, "Giant", NULL, MTX_DEF | MTX_RECURSE); 1196 mtx_init(&blocked_lock, "blocked lock", NULL, MTX_SPIN); 1197 blocked_lock.mtx_lock = 0xdeadc0de; /* Always blocked. */ 1198 mtx_init(&proc0.p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK); 1199 mtx_init(&proc0.p_slock, "process slock", NULL, MTX_SPIN); 1200 mtx_init(&proc0.p_statmtx, "pstatl", NULL, MTX_SPIN); 1201 mtx_init(&proc0.p_itimmtx, "pitiml", NULL, MTX_SPIN); 1202 mtx_init(&proc0.p_profmtx, "pprofl", NULL, MTX_SPIN); 1203 mtx_init(&devmtx, "cdev", NULL, MTX_DEF); 1204 mtx_lock(&Giant); 1205 } 1206 1207 static void __noinline 1208 _mtx_lock_indefinite_check(struct mtx *m, struct lock_delay_arg *ldap) 1209 { 1210 struct thread *td; 1211 1212 ldap->spin_cnt++; 1213 if (ldap->spin_cnt < 60000000 || kdb_active || panicstr != NULL) 1214 DELAY(1); 1215 else { 1216 td = mtx_owner(m); 1217 1218 /* If the mutex is unlocked, try again. */ 1219 if (td == NULL) 1220 return; 1221 1222 printf( "spin lock %p (%s) held by %p (tid %d) too long\n", 1223 m, m->lock_object.lo_name, td, td->td_tid); 1224 #ifdef WITNESS 1225 witness_display_spinlock(&m->lock_object, td, printf); 1226 #endif 1227 panic("spin lock held too long"); 1228 } 1229 cpu_spinwait(); 1230 } 1231 1232 void 1233 mtx_spin_wait_unlocked(struct mtx *m) 1234 { 1235 struct lock_delay_arg lda; 1236 1237 KASSERT(m->mtx_lock != MTX_DESTROYED, 1238 ("%s() of destroyed mutex %p", __func__, m)); 1239 KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, 1240 ("%s() of sleep mutex %p (%s)", __func__, m, 1241 m->lock_object.lo_name)); 1242 KASSERT(!mtx_owned(m), ("%s() waiting on myself on lock %p (%s)", __func__, m, 1243 m->lock_object.lo_name)); 1244 1245 lda.spin_cnt = 0; 1246 1247 while (atomic_load_acq_ptr(&m->mtx_lock) != MTX_UNOWNED) { 1248 if (__predict_true(lda.spin_cnt < 10000000)) { 1249 cpu_spinwait(); 1250 lda.spin_cnt++; 1251 } else { 1252 _mtx_lock_indefinite_check(m, &lda); 1253 } 1254 } 1255 } 1256 1257 #ifdef DDB 1258 void 1259 db_show_mtx(const struct lock_object *lock) 1260 { 1261 struct thread *td; 1262 const struct mtx *m; 1263 1264 m = (const struct mtx *)lock; 1265 1266 db_printf(" flags: {"); 1267 if (LOCK_CLASS(lock) == &lock_class_mtx_spin) 1268 db_printf("SPIN"); 1269 else 1270 db_printf("DEF"); 1271 if (m->lock_object.lo_flags & LO_RECURSABLE) 1272 db_printf(", RECURSE"); 1273 if (m->lock_object.lo_flags & LO_DUPOK) 1274 db_printf(", DUPOK"); 1275 db_printf("}\n"); 1276 db_printf(" state: {"); 1277 if (mtx_unowned(m)) 1278 db_printf("UNOWNED"); 1279 else if (mtx_destroyed(m)) 1280 db_printf("DESTROYED"); 1281 else { 1282 db_printf("OWNED"); 1283 if (m->mtx_lock & MTX_CONTESTED) 1284 db_printf(", CONTESTED"); 1285 if (m->mtx_lock & MTX_RECURSED) 1286 db_printf(", RECURSED"); 1287 } 1288 db_printf("}\n"); 1289 if (!mtx_unowned(m) && !mtx_destroyed(m)) { 1290 td = mtx_owner(m); 1291 db_printf(" owner: %p (tid %d, pid %d, \"%s\")\n", td, 1292 td->td_tid, td->td_proc->p_pid, td->td_name); 1293 if (mtx_recursed(m)) 1294 db_printf(" recursed: %d\n", m->mtx_recurse); 1295 } 1296 } 1297 #endif 1298