kern_lock.c revision 201709
1139804Simp/*- 2177957Sattilio * Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org> 3177957Sattilio * All rights reserved. 424269Speter * 524269Speter * Redistribution and use in source and binary forms, with or without 624269Speter * modification, are permitted provided that the following conditions 724269Speter * are met: 824269Speter * 1. Redistributions of source code must retain the above copyright 9177957Sattilio * notice(s), this list of conditions and the following disclaimer as 10177957Sattilio * the first lines of this file unmodified other than the possible 11177957Sattilio * addition of one or more copyright notices. 1224269Speter * 2. Redistributions in binary form must reproduce the above copyright 13177957Sattilio * notice(s), this list of conditions and the following disclaimer in the 1424269Speter * documentation and/or other materials provided with the distribution. 1524269Speter * 16177957Sattilio * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY 17177957Sattilio * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18177957Sattilio * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19177957Sattilio * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY 20177957Sattilio * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21177957Sattilio * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22177957Sattilio * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 23177957Sattilio * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2424269Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25177957Sattilio * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 26177957Sattilio * DAMAGE. 2724269Speter */ 2824269Speter 29194317Sattilio#include "opt_adaptive_lockmgrs.h" 30177957Sattilio#include "opt_ddb.h" 31192853Ssson#include "opt_kdtrace.h" 32177957Sattilio 33116182Sobrien#include <sys/cdefs.h> 34116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/kern_lock.c 201709 2010-01-07 01:19:01Z attilio $"); 35116182Sobrien 3624269Speter#include <sys/param.h> 3784812Sjhb#include <sys/ktr.h> 38194317Sattilio#include <sys/linker_set.h> 3924269Speter#include <sys/lock.h> 40177957Sattilio#include <sys/lock_profile.h> 41102477Sbde#include <sys/lockmgr.h> 4267353Sjhb#include <sys/mutex.h> 43102477Sbde#include <sys/proc.h> 44177957Sattilio#include <sys/sleepqueue.h> 45148668Sjeff#ifdef DEBUG_LOCKS 46148668Sjeff#include <sys/stack.h> 47148668Sjeff#endif 48194317Sattilio#include <sys/sysctl.h> 49177957Sattilio#include <sys/systm.h> 5024269Speter 51177957Sattilio#include <machine/cpu.h> 52176014Sattilio 53161322Sjhb#ifdef DDB 54161322Sjhb#include <ddb/ddb.h> 55161322Sjhb#endif 56161322Sjhb 57194317SattilioCTASSERT(((LK_ADAPTIVE | LK_NOSHARE) & LO_CLASSFLAGS) == 58194317Sattilio (LK_ADAPTIVE | LK_NOSHARE)); 59194317SattilioCTASSERT(LK_UNLOCKED == (LK_UNLOCKED & 60194317Sattilio ~(LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS))); 61177957Sattilio 62177957Sattilio#define SQ_EXCLUSIVE_QUEUE 0 63177957Sattilio#define SQ_SHARED_QUEUE 1 64177957Sattilio 65177957Sattilio#ifndef INVARIANTS 66177957Sattilio#define _lockmgr_assert(lk, what, file, line) 67177957Sattilio#define TD_LOCKS_INC(td) 68177957Sattilio#define TD_LOCKS_DEC(td) 69177957Sattilio#else 70177957Sattilio#define TD_LOCKS_INC(td) ((td)->td_locks++) 71177957Sattilio#define TD_LOCKS_DEC(td) ((td)->td_locks--) 72177957Sattilio#endif 73177957Sattilio#define TD_SLOCKS_INC(td) ((td)->td_lk_slocks++) 74177957Sattilio#define TD_SLOCKS_DEC(td) ((td)->td_lk_slocks--) 75177957Sattilio 76177957Sattilio#ifndef DEBUG_LOCKS 77177957Sattilio#define STACK_PRINT(lk) 78177957Sattilio#define STACK_SAVE(lk) 79177957Sattilio#define STACK_ZERO(lk) 80177957Sattilio#else 81177957Sattilio#define STACK_PRINT(lk) stack_print_ddb(&(lk)->lk_stack) 82177957Sattilio#define STACK_SAVE(lk) stack_save(&(lk)->lk_stack) 83177957Sattilio#define STACK_ZERO(lk) stack_zero(&(lk)->lk_stack) 84177957Sattilio#endif 85177957Sattilio 86177957Sattilio#define LOCK_LOG2(lk, string, arg1, arg2) \ 87177957Sattilio if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \ 88177957Sattilio CTR2(KTR_LOCK, (string), (arg1), (arg2)) 89177957Sattilio#define LOCK_LOG3(lk, string, arg1, arg2, arg3) \ 90177957Sattilio if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \ 91177957Sattilio CTR3(KTR_LOCK, (string), (arg1), (arg2), (arg3)) 92177957Sattilio 93178159Sattilio#define GIANT_DECLARE \ 94178159Sattilio int _i = 0; \ 95178159Sattilio WITNESS_SAVE_DECL(Giant) 96178159Sattilio#define GIANT_RESTORE() do { \ 97178159Sattilio if (_i > 0) { \ 98178159Sattilio while (_i--) \ 99178159Sattilio mtx_lock(&Giant); \ 100178159Sattilio WITNESS_RESTORE(&Giant.lock_object, Giant); \ 101178159Sattilio } \ 102178159Sattilio} while (0) 103178159Sattilio#define GIANT_SAVE() do { \ 104178159Sattilio if (mtx_owned(&Giant)) { \ 105178159Sattilio WITNESS_SAVE(&Giant.lock_object, Giant); \ 106178159Sattilio while (mtx_owned(&Giant)) { \ 107178159Sattilio _i++; \ 108178159Sattilio mtx_unlock(&Giant); \ 109178159Sattilio } \ 110178159Sattilio } \ 111178159Sattilio} while (0) 112178159Sattilio 113177957Sattilio#define LK_CAN_SHARE(x) \ 114177957Sattilio (((x) & LK_SHARE) && (((x) & LK_EXCLUSIVE_WAITERS) == 0 || \ 115194317Sattilio ((x) & LK_EXCLUSIVE_SPINNERS) == 0 || \ 116177982Sattilio curthread->td_lk_slocks || (curthread->td_pflags & TDP_DEADLKTREAT))) 117178159Sattilio#define LK_TRYOP(x) \ 118178159Sattilio ((x) & LK_NOWAIT) 119177957Sattilio 120178159Sattilio#define LK_CAN_WITNESS(x) \ 121178159Sattilio (((x) & LK_NOWITNESS) == 0 && !LK_TRYOP(x)) 122178159Sattilio#define LK_TRYWIT(x) \ 123178159Sattilio (LK_TRYOP(x) ? LOP_TRYLOCK : 0) 124178159Sattilio 125194317Sattilio#define LK_CAN_ADAPT(lk, f) \ 126194317Sattilio (((lk)->lock_object.lo_flags & LK_ADAPTIVE) != 0 && \ 127194317Sattilio ((f) & LK_SLEEPFAIL) == 0) 128194317Sattilio 129177957Sattilio#define lockmgr_disowned(lk) \ 130177957Sattilio (((lk)->lk_lock & ~(LK_FLAGMASK & ~LK_SHARE)) == LK_KERNPROC) 131177957Sattilio 132177957Sattilio#define lockmgr_xlocked(lk) \ 133177957Sattilio (((lk)->lk_lock & ~(LK_FLAGMASK & ~LK_SHARE)) == (uintptr_t)curthread) 134177957Sattilio 135177957Sattiliostatic void assert_lockmgr(struct lock_object *lock, int how); 136177957Sattilio#ifdef DDB 137177957Sattiliostatic void db_show_lockmgr(struct lock_object *lock); 138177957Sattilio#endif 139177957Sattiliostatic void lock_lockmgr(struct lock_object *lock, int how); 140192853Ssson#ifdef KDTRACE_HOOKS 141192853Sssonstatic int owner_lockmgr(struct lock_object *lock, struct thread **owner); 142192853Ssson#endif 143177957Sattiliostatic int unlock_lockmgr(struct lock_object *lock); 144177957Sattilio 145164246Skmacystruct lock_class lock_class_lockmgr = { 146167366Sjhb .lc_name = "lockmgr", 147177957Sattilio .lc_flags = LC_RECURSABLE | LC_SLEEPABLE | LC_SLEEPLOCK | LC_UPGRADABLE, 148173733Sattilio .lc_assert = assert_lockmgr, 149164246Skmacy#ifdef DDB 150167368Sjhb .lc_ddb_show = db_show_lockmgr, 151164246Skmacy#endif 152167368Sjhb .lc_lock = lock_lockmgr, 153192853Ssson .lc_unlock = unlock_lockmgr, 154192853Ssson#ifdef KDTRACE_HOOKS 155192853Ssson .lc_owner = owner_lockmgr, 156192853Ssson#endif 157164246Skmacy}; 158164246Skmacy 159194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 160194317Sattiliostatic u_int alk_retries = 10; 161194317Sattiliostatic u_int alk_loops = 10000; 162194317SattilioSYSCTL_NODE(_debug, OID_AUTO, lockmgr, CTLFLAG_RD, NULL, "lockmgr debugging"); 163194317SattilioSYSCTL_UINT(_debug_lockmgr, OID_AUTO, retries, CTLFLAG_RW, &alk_retries, 0, ""); 164194317SattilioSYSCTL_UINT(_debug_lockmgr, OID_AUTO, loops, CTLFLAG_RW, &alk_loops, 0, ""); 165194317Sattilio#endif 166194317Sattilio 167177957Sattiliostatic __inline struct thread * 168177957Sattiliolockmgr_xholder(struct lock *lk) 169177957Sattilio{ 170177957Sattilio uintptr_t x; 171176249Sattilio 172177957Sattilio x = lk->lk_lock; 173177957Sattilio return ((x & LK_SHARE) ? NULL : (struct thread *)LK_HOLDER(x)); 174177957Sattilio} 175177957Sattilio 17624269Speter/* 177177957Sattilio * It assumes sleepq_lock held and returns with this one unheld. 178177957Sattilio * It also assumes the generic interlock is sane and previously checked. 179177957Sattilio * If LK_INTERLOCK is specified the interlock is not reacquired after the 180177957Sattilio * sleep. 18124269Speter */ 182177957Sattiliostatic __inline int 183177957Sattiliosleeplk(struct lock *lk, u_int flags, struct lock_object *ilk, 184177957Sattilio const char *wmesg, int pri, int timo, int queue) 185177957Sattilio{ 186178159Sattilio GIANT_DECLARE; 187177957Sattilio struct lock_class *class; 188177957Sattilio int catch, error; 18924269Speter 190177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 191179306Sattilio catch = pri & PCATCH; 192177957Sattilio pri &= PRIMASK; 193177957Sattilio error = 0; 194177957Sattilio 195177957Sattilio LOCK_LOG3(lk, "%s: %p blocking on the %s sleepqueue", __func__, lk, 196177957Sattilio (queue == SQ_EXCLUSIVE_QUEUE) ? "exclusive" : "shared"); 197177957Sattilio 198177957Sattilio if (flags & LK_INTERLOCK) 199177957Sattilio class->lc_unlock(ilk); 200200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE && (flags & LK_SLEEPFAIL) != 0) 201200447Sattilio lk->lk_exslpfail++; 202178159Sattilio GIANT_SAVE(); 203177957Sattilio sleepq_add(&lk->lock_object, NULL, wmesg, SLEEPQ_LK | (catch ? 204177957Sattilio SLEEPQ_INTERRUPTIBLE : 0), queue); 205177957Sattilio if ((flags & LK_TIMELOCK) && timo) 206177957Sattilio sleepq_set_timeout(&lk->lock_object, timo); 207177957Sattilio 208177957Sattilio /* 209177957Sattilio * Decisional switch for real sleeping. 210177957Sattilio */ 211177957Sattilio if ((flags & LK_TIMELOCK) && timo && catch) 212177957Sattilio error = sleepq_timedwait_sig(&lk->lock_object, pri); 213177957Sattilio else if ((flags & LK_TIMELOCK) && timo) 214177957Sattilio error = sleepq_timedwait(&lk->lock_object, pri); 215177957Sattilio else if (catch) 216177957Sattilio error = sleepq_wait_sig(&lk->lock_object, pri); 217177957Sattilio else 218177957Sattilio sleepq_wait(&lk->lock_object, pri); 219178159Sattilio GIANT_RESTORE(); 220177957Sattilio if ((flags & LK_SLEEPFAIL) && error == 0) 221177957Sattilio error = ENOLCK; 222177957Sattilio 223177957Sattilio return (error); 224177957Sattilio} 225177957Sattilio 226181334Sjhbstatic __inline int 227177957Sattiliowakeupshlk(struct lock *lk, const char *file, int line) 228177957Sattilio{ 229177957Sattilio uintptr_t v, x; 230200447Sattilio u_int realexslp; 231181334Sjhb int queue, wakeup_swapper; 232177957Sattilio 233177957Sattilio TD_LOCKS_DEC(curthread); 234177957Sattilio TD_SLOCKS_DEC(curthread); 235178159Sattilio WITNESS_UNLOCK(&lk->lock_object, 0, file, line); 236177957Sattilio LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, file, line); 237177957Sattilio 238181334Sjhb wakeup_swapper = 0; 239177957Sattilio for (;;) { 240177957Sattilio x = lk->lk_lock; 241177957Sattilio 242177957Sattilio /* 243177957Sattilio * If there is more than one shared lock held, just drop one 244177957Sattilio * and return. 245177957Sattilio */ 246177957Sattilio if (LK_SHARERS(x) > 1) { 247197735Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, x, 248177957Sattilio x - LK_ONE_SHARER)) 249177957Sattilio break; 250177957Sattilio continue; 251177957Sattilio } 252177957Sattilio 253177957Sattilio /* 254177957Sattilio * If there are not waiters on the exclusive queue, drop the 255177957Sattilio * lock quickly. 256177957Sattilio */ 257177957Sattilio if ((x & LK_ALL_WAITERS) == 0) { 258194317Sattilio MPASS((x & ~LK_EXCLUSIVE_SPINNERS) == 259194317Sattilio LK_SHARERS_LOCK(1)); 260197735Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, x, LK_UNLOCKED)) 261177957Sattilio break; 262177957Sattilio continue; 263177957Sattilio } 264177957Sattilio 265177957Sattilio /* 266177957Sattilio * We should have a sharer with waiters, so enter the hard 267177957Sattilio * path in order to handle wakeups correctly. 268177957Sattilio */ 269177957Sattilio sleepq_lock(&lk->lock_object); 270194317Sattilio x = lk->lk_lock & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 271177957Sattilio v = LK_UNLOCKED; 272177957Sattilio 273177957Sattilio /* 274177957Sattilio * If the lock has exclusive waiters, give them preference in 275177957Sattilio * order to avoid deadlock with shared runners up. 276200447Sattilio * If interruptible sleeps left the exclusive queue empty 277200447Sattilio * avoid a starvation for the threads sleeping on the shared 278200447Sattilio * queue by giving them precedence and cleaning up the 279200447Sattilio * exclusive waiters bit anyway. 280201709Sattilio * Please note that lk_exslpfail count may be lying about 281201709Sattilio * the real number of waiters with the LK_SLEEPFAIL flag on 282201709Sattilio * because they may be used in conjuction with interruptible 283201709Sattilio * sleeps so lk_exslpfail is consider as a 'upper limit' 284201709Sattilio * bound, considering the edge cases. 285177957Sattilio */ 286200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 287200447Sattilio SQ_EXCLUSIVE_QUEUE); 288200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 289200447Sattilio if (lk->lk_exslpfail < realexslp) { 290200447Sattilio lk->lk_exslpfail = 0; 291200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 292200447Sattilio v |= (x & LK_SHARED_WAITERS); 293200447Sattilio } else { 294200447Sattilio lk->lk_exslpfail = 0; 295200447Sattilio LOCK_LOG2(lk, 296200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 297200447Sattilio __func__, lk); 298200447Sattilio LOCK_LOG2(lk, 299200447Sattilio "%s: %p waking up threads on the exclusive queue", 300200447Sattilio __func__, lk); 301200447Sattilio wakeup_swapper = 302200447Sattilio sleepq_broadcast(&lk->lock_object, 303200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 304200447Sattilio queue = SQ_SHARED_QUEUE; 305200447Sattilio } 306200447Sattilio 307177957Sattilio } else { 308201703Sattilio 309201703Sattilio /* 310201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL on 311201703Sattilio * and using interruptible sleeps/timeout may have 312201703Sattilio * left spourious lk_exslpfail counts on, so clean 313201703Sattilio * it up anyway. 314201703Sattilio */ 315201703Sattilio lk->lk_exslpfail = 0; 316177957Sattilio queue = SQ_SHARED_QUEUE; 317177957Sattilio } 318177957Sattilio 319197735Sattilio if (!atomic_cmpset_rel_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x, 320177957Sattilio v)) { 321177957Sattilio sleepq_release(&lk->lock_object); 322177957Sattilio continue; 323177957Sattilio } 324177957Sattilio LOCK_LOG3(lk, "%s: %p waking up threads on the %s queue", 325177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 326177957Sattilio "exclusive"); 327200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, SLEEPQ_LK, 328181334Sjhb 0, queue); 329177957Sattilio sleepq_release(&lk->lock_object); 330177957Sattilio break; 331177957Sattilio } 332177957Sattilio 333177957Sattilio lock_profile_release_lock(&lk->lock_object); 334181334Sjhb return (wakeup_swapper); 335177957Sattilio} 336177957Sattilio 337177957Sattiliostatic void 338173733Sattilioassert_lockmgr(struct lock_object *lock, int what) 339173733Sattilio{ 340173733Sattilio 341173733Sattilio panic("lockmgr locks do not support assertions"); 342173733Sattilio} 343173733Sattilio 344177957Sattiliostatic void 345167368Sjhblock_lockmgr(struct lock_object *lock, int how) 346167368Sjhb{ 347167368Sjhb 348167368Sjhb panic("lockmgr locks do not support sleep interlocking"); 349167368Sjhb} 350167368Sjhb 351177957Sattiliostatic int 352167368Sjhbunlock_lockmgr(struct lock_object *lock) 353167368Sjhb{ 354167368Sjhb 355167368Sjhb panic("lockmgr locks do not support sleep interlocking"); 356167368Sjhb} 357167368Sjhb 358192853Ssson#ifdef KDTRACE_HOOKS 359192853Sssonstatic int 360192853Sssonowner_lockmgr(struct lock_object *lock, struct thread **owner) 361192853Ssson{ 362192853Ssson 363192853Ssson panic("lockmgr locks do not support owner inquiring"); 364192853Ssson} 365192853Ssson#endif 366192853Ssson 367177957Sattiliovoid 368177957Sattiliolockinit(struct lock *lk, int pri, const char *wmesg, int timo, int flags) 369177957Sattilio{ 370177957Sattilio int iflags; 37129653Sdyson 372177957Sattilio MPASS((flags & ~LK_INIT_MASK) == 0); 373196334Sattilio ASSERT_ATOMIC_LOAD_PTR(lk->lk_lock, 374196334Sattilio ("%s: lockmgr not aligned for %s: %p", __func__, wmesg, 375196334Sattilio &lk->lk_lock)); 37624269Speter 377193307Sattilio iflags = LO_SLEEPABLE | LO_UPGRADABLE; 378193307Sattilio if (flags & LK_CANRECURSE) 379193307Sattilio iflags |= LO_RECURSABLE; 380177957Sattilio if ((flags & LK_NODUP) == 0) 381177957Sattilio iflags |= LO_DUPOK; 382177957Sattilio if (flags & LK_NOPROFILE) 383177957Sattilio iflags |= LO_NOPROFILE; 384177957Sattilio if ((flags & LK_NOWITNESS) == 0) 385177957Sattilio iflags |= LO_WITNESS; 386177957Sattilio if (flags & LK_QUIET) 387177957Sattilio iflags |= LO_QUIET; 388194317Sattilio iflags |= flags & (LK_ADAPTIVE | LK_NOSHARE); 389177957Sattilio 390177957Sattilio lk->lk_lock = LK_UNLOCKED; 391177957Sattilio lk->lk_recurse = 0; 392200447Sattilio lk->lk_exslpfail = 0; 393177957Sattilio lk->lk_timo = timo; 394177957Sattilio lk->lk_pri = pri; 395177957Sattilio lock_init(&lk->lock_object, &lock_class_lockmgr, wmesg, NULL, iflags); 396177957Sattilio STACK_ZERO(lk); 39728345Sdyson} 39824269Speter 399177957Sattiliovoid 400177957Sattiliolockdestroy(struct lock *lk) 401177957Sattilio{ 40242453Seivind 403177957Sattilio KASSERT(lk->lk_lock == LK_UNLOCKED, ("lockmgr still held")); 404177957Sattilio KASSERT(lk->lk_recurse == 0, ("lockmgr still recursed")); 405200447Sattilio KASSERT(lk->lk_exslpfail == 0, ("lockmgr still exclusive waiters")); 406177957Sattilio lock_destroy(&lk->lock_object); 40728345Sdyson} 40828345Sdyson 409177957Sattilioint 410177957Sattilio__lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, 411177957Sattilio const char *wmesg, int pri, int timo, const char *file, int line) 412140711Sjeff{ 413178159Sattilio GIANT_DECLARE; 414177957Sattilio struct lock_class *class; 415176320Sattilio const char *iwmesg; 416177957Sattilio uintptr_t tid, v, x; 417200447Sattilio u_int op, realexslp; 418189846Sjeff int error, ipri, itimo, queue, wakeup_swapper; 419189846Sjeff#ifdef LOCK_PROFILING 420189846Sjeff uint64_t waittime = 0; 421189846Sjeff int contested = 0; 422189846Sjeff#endif 423194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 424194317Sattilio volatile struct thread *owner; 425194317Sattilio u_int i, spintries = 0; 426194317Sattilio#endif 427176320Sattilio 428177957Sattilio error = 0; 429177957Sattilio tid = (uintptr_t)curthread; 430177957Sattilio op = (flags & LK_TYPE_MASK); 431177957Sattilio iwmesg = (wmesg == LK_WMESG_DEFAULT) ? lk->lock_object.lo_name : wmesg; 432177957Sattilio ipri = (pri == LK_PRIO_DEFAULT) ? lk->lk_pri : pri; 433177957Sattilio itimo = (timo == LK_TIMO_DEFAULT) ? lk->lk_timo : timo; 434176320Sattilio 435177957Sattilio MPASS((flags & ~LK_TOTAL_MASK) == 0); 436178150Sattilio KASSERT((op & (op - 1)) == 0, 437178150Sattilio ("%s: Invalid requested operation @ %s:%d", __func__, file, line)); 438177957Sattilio KASSERT((flags & (LK_NOWAIT | LK_SLEEPFAIL)) == 0 || 439177957Sattilio (op != LK_DOWNGRADE && op != LK_RELEASE), 440177957Sattilio ("%s: Invalid flags in regard of the operation desired @ %s:%d", 441177957Sattilio __func__, file, line)); 442177957Sattilio KASSERT((flags & LK_INTERLOCK) == 0 || ilk != NULL, 443177957Sattilio ("%s: LK_INTERLOCK passed without valid interlock @ %s:%d", 444177957Sattilio __func__, file, line)); 44566615Sjasone 446177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 447177957Sattilio if (panicstr != NULL) { 448177957Sattilio if (flags & LK_INTERLOCK) 449177957Sattilio class->lc_unlock(ilk); 450177957Sattilio return (0); 45128345Sdyson } 45228345Sdyson 453177957Sattilio if (op == LK_SHARED && (lk->lock_object.lo_flags & LK_NOSHARE)) 454177957Sattilio op = LK_EXCLUSIVE; 455164159Skmacy 456181334Sjhb wakeup_swapper = 0; 457177957Sattilio switch (op) { 458177957Sattilio case LK_SHARED: 459178159Sattilio if (LK_CAN_WITNESS(flags)) 460178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, 461182914Sjhb file, line, ilk); 462177957Sattilio for (;;) { 463177957Sattilio x = lk->lk_lock; 464174948Sattilio 465177957Sattilio /* 466177957Sattilio * If no other thread has an exclusive lock, or 467177957Sattilio * no exclusive waiter is present, bump the count of 468177957Sattilio * sharers. Since we have to preserve the state of 469177957Sattilio * waiters, if we fail to acquire the shared lock 470177957Sattilio * loop back and retry. 471177957Sattilio */ 472177957Sattilio if (LK_CAN_SHARE(x)) { 473177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 474177957Sattilio x + LK_ONE_SHARER)) 475177957Sattilio break; 476177957Sattilio continue; 477177957Sattilio } 478177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 479177957Sattilio &contested, &waittime); 48028345Sdyson 481177957Sattilio /* 482180798Skib * If the lock is already held by curthread in 483177957Sattilio * exclusive way avoid a deadlock. 484177957Sattilio */ 485177957Sattilio if (LK_HOLDER(x) == tid) { 486177957Sattilio LOCK_LOG2(lk, 487180798Skib "%s: %p already held in exclusive mode", 488177957Sattilio __func__, lk); 489177957Sattilio error = EDEADLK; 490177957Sattilio break; 491177957Sattilio } 492140711Sjeff 493177957Sattilio /* 494177957Sattilio * If the lock is expected to not sleep just give up 495177957Sattilio * and return. 496177957Sattilio */ 497177957Sattilio if (LK_TRYOP(flags)) { 498177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 499177957Sattilio __func__, lk); 500177957Sattilio error = EBUSY; 501177957Sattilio break; 502177957Sattilio } 50328345Sdyson 504194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 505177957Sattilio /* 506194317Sattilio * If the owner is running on another CPU, spin until 507194317Sattilio * the owner stops running or the state of the lock 508196772Sattilio * changes. We need a double-state handle here 509196772Sattilio * because for a failed acquisition the lock can be 510196772Sattilio * either held in exclusive mode or shared mode 511196772Sattilio * (for the writer starvation avoidance technique). 512194317Sattilio */ 513194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 514194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 515194317Sattilio owner = (struct thread *)LK_HOLDER(x); 516194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 517194317Sattilio CTR3(KTR_LOCK, 518194317Sattilio "%s: spinning on %p held by %p", 519194317Sattilio __func__, lk, owner); 520194317Sattilio 521194317Sattilio /* 522194317Sattilio * If we are holding also an interlock drop it 523194317Sattilio * in order to avoid a deadlock if the lockmgr 524194317Sattilio * owner is adaptively spinning on the 525194317Sattilio * interlock itself. 526194317Sattilio */ 527194317Sattilio if (flags & LK_INTERLOCK) { 528194317Sattilio class->lc_unlock(ilk); 529194317Sattilio flags &= ~LK_INTERLOCK; 530194317Sattilio } 531194317Sattilio GIANT_SAVE(); 532194317Sattilio while (LK_HOLDER(lk->lk_lock) == 533194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 534194317Sattilio cpu_spinwait(); 535196772Sattilio GIANT_RESTORE(); 536196772Sattilio continue; 537194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 538196772Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 539194317Sattilio spintries < alk_retries) { 540194317Sattilio if (flags & LK_INTERLOCK) { 541194317Sattilio class->lc_unlock(ilk); 542194317Sattilio flags &= ~LK_INTERLOCK; 543194317Sattilio } 544194317Sattilio GIANT_SAVE(); 545194317Sattilio spintries++; 546194317Sattilio for (i = 0; i < alk_loops; i++) { 547194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 548194317Sattilio CTR4(KTR_LOCK, 549194317Sattilio "%s: shared spinning on %p with %u and %u", 550194317Sattilio __func__, lk, spintries, i); 551194317Sattilio x = lk->lk_lock; 552194317Sattilio if ((x & LK_SHARE) == 0 || 553194317Sattilio LK_CAN_SHARE(x) != 0) 554194317Sattilio break; 555194317Sattilio cpu_spinwait(); 556194317Sattilio } 557196772Sattilio GIANT_RESTORE(); 558194317Sattilio if (i != alk_loops) 559194317Sattilio continue; 560194317Sattilio } 561194317Sattilio#endif 562194317Sattilio 563194317Sattilio /* 564177957Sattilio * Acquire the sleepqueue chain lock because we 565177957Sattilio * probabilly will need to manipulate waiters flags. 566177957Sattilio */ 567177957Sattilio sleepq_lock(&lk->lock_object); 568177957Sattilio x = lk->lk_lock; 569111463Sjeff 570177957Sattilio /* 571177957Sattilio * if the lock can be acquired in shared mode, try 572177957Sattilio * again. 573177957Sattilio */ 574177957Sattilio if (LK_CAN_SHARE(x)) { 575177957Sattilio sleepq_release(&lk->lock_object); 576177957Sattilio continue; 577177957Sattilio } 57824269Speter 579194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 580177957Sattilio /* 581194317Sattilio * The current lock owner might have started executing 582194317Sattilio * on another CPU (or the lock could have changed 583194317Sattilio * owner) while we were waiting on the turnstile 584194317Sattilio * chain lock. If so, drop the turnstile lock and try 585194317Sattilio * again. 586194317Sattilio */ 587194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 588194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 589194317Sattilio owner = (struct thread *)LK_HOLDER(x); 590194317Sattilio if (TD_IS_RUNNING(owner)) { 591194317Sattilio sleepq_release(&lk->lock_object); 592194317Sattilio continue; 593194317Sattilio } 594194317Sattilio } 595194317Sattilio#endif 596194317Sattilio 597194317Sattilio /* 598177957Sattilio * Try to set the LK_SHARED_WAITERS flag. If we fail, 599177957Sattilio * loop back and retry. 600177957Sattilio */ 601177957Sattilio if ((x & LK_SHARED_WAITERS) == 0) { 602177957Sattilio if (!atomic_cmpset_acq_ptr(&lk->lk_lock, x, 603177957Sattilio x | LK_SHARED_WAITERS)) { 604177957Sattilio sleepq_release(&lk->lock_object); 605177957Sattilio continue; 606177957Sattilio } 607177957Sattilio LOCK_LOG2(lk, "%s: %p set shared waiters flag", 608177957Sattilio __func__, lk); 609177957Sattilio } 61024269Speter 611177957Sattilio /* 612177957Sattilio * As far as we have been unable to acquire the 613177957Sattilio * shared lock and the shared waiters flag is set, 614177957Sattilio * we will sleep. 615177957Sattilio */ 616177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 617177957Sattilio SQ_SHARED_QUEUE); 618177957Sattilio flags &= ~LK_INTERLOCK; 619177957Sattilio if (error) { 620177957Sattilio LOCK_LOG3(lk, 621177957Sattilio "%s: interrupted sleep for %p with %d", 622177957Sattilio __func__, lk, error); 623177957Sattilio break; 624177957Sattilio } 625177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 626177957Sattilio __func__, lk); 627177957Sattilio } 628177957Sattilio if (error == 0) { 629177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 630177957Sattilio contested, waittime, file, line); 631177957Sattilio LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, file, 632176014Sattilio line); 633178159Sattilio WITNESS_LOCK(&lk->lock_object, LK_TRYWIT(flags), file, 634178159Sattilio line); 635177957Sattilio TD_LOCKS_INC(curthread); 636177957Sattilio TD_SLOCKS_INC(curthread); 637177957Sattilio STACK_SAVE(lk); 638177957Sattilio } 639177957Sattilio break; 640177957Sattilio case LK_UPGRADE: 641177957Sattilio _lockmgr_assert(lk, KA_SLOCKED, file, line); 642194317Sattilio v = lk->lk_lock; 643194317Sattilio x = v & LK_ALL_WAITERS; 644194317Sattilio v &= LK_EXCLUSIVE_SPINNERS; 645177957Sattilio 64644681Sjulian /* 647177957Sattilio * Try to switch from one shared lock to an exclusive one. 648177957Sattilio * We need to preserve waiters flags during the operation. 64944681Sjulian */ 650194317Sattilio if (atomic_cmpset_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x | v, 651177957Sattilio tid | x)) { 652177957Sattilio LOCK_LOG_LOCK("XUPGRADE", &lk->lock_object, 0, 0, file, 653177957Sattilio line); 654178159Sattilio WITNESS_UPGRADE(&lk->lock_object, LOP_EXCLUSIVE | 655178159Sattilio LK_TRYWIT(flags), file, line); 656177957Sattilio TD_SLOCKS_DEC(curthread); 65724269Speter break; 65824269Speter } 659177957Sattilio 66024269Speter /* 661177957Sattilio * We have been unable to succeed in upgrading, so just 662177957Sattilio * give up the shared lock. 66324269Speter */ 664182010Sjhb wakeup_swapper |= wakeupshlk(lk, file, line); 66524269Speter 666177957Sattilio /* FALLTHROUGH */ 667177957Sattilio case LK_EXCLUSIVE: 668178159Sattilio if (LK_CAN_WITNESS(flags)) 669178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 670182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 67124269Speter 67224269Speter /* 673180798Skib * If curthread already holds the lock and this one is 674177957Sattilio * allowed to recurse, simply recurse on it. 67524269Speter */ 676177957Sattilio if (lockmgr_xlocked(lk)) { 677177957Sattilio if ((flags & LK_CANRECURSE) == 0 && 678193307Sattilio (lk->lock_object.lo_flags & LO_RECURSABLE) == 0) { 679177957Sattilio 680177957Sattilio /* 681177957Sattilio * If the lock is expected to not panic just 682177957Sattilio * give up and return. 683177957Sattilio */ 684177957Sattilio if (LK_TRYOP(flags)) { 685177957Sattilio LOCK_LOG2(lk, 686177957Sattilio "%s: %p fails the try operation", 687177957Sattilio __func__, lk); 688177957Sattilio error = EBUSY; 689177957Sattilio break; 690177957Sattilio } 691177957Sattilio if (flags & LK_INTERLOCK) 692177957Sattilio class->lc_unlock(ilk); 693177957Sattilio panic("%s: recursing on non recursive lockmgr %s @ %s:%d\n", 694177957Sattilio __func__, iwmesg, file, line); 695177957Sattilio } 696177957Sattilio lk->lk_recurse++; 697177957Sattilio LOCK_LOG2(lk, "%s: %p recursing", __func__, lk); 698177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 699177957Sattilio lk->lk_recurse, file, line); 700178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 701178159Sattilio LK_TRYWIT(flags), file, line); 702177957Sattilio TD_LOCKS_INC(curthread); 70324269Speter break; 70424269Speter } 705177957Sattilio 706177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, 707177957Sattilio tid)) { 708177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 709177957Sattilio &contested, &waittime); 710177957Sattilio 71124269Speter /* 712177957Sattilio * If the lock is expected to not sleep just give up 713177957Sattilio * and return. 71424269Speter */ 715177957Sattilio if (LK_TRYOP(flags)) { 716177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 717177957Sattilio __func__, lk); 718177957Sattilio error = EBUSY; 719177957Sattilio break; 720177957Sattilio } 72134194Sdyson 722194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 723177957Sattilio /* 724194317Sattilio * If the owner is running on another CPU, spin until 725194317Sattilio * the owner stops running or the state of the lock 726194317Sattilio * changes. 727194317Sattilio */ 728194317Sattilio x = lk->lk_lock; 729194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 730194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 731194317Sattilio owner = (struct thread *)LK_HOLDER(x); 732194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 733194317Sattilio CTR3(KTR_LOCK, 734194317Sattilio "%s: spinning on %p held by %p", 735194317Sattilio __func__, lk, owner); 736194317Sattilio 737194317Sattilio /* 738194317Sattilio * If we are holding also an interlock drop it 739194317Sattilio * in order to avoid a deadlock if the lockmgr 740194317Sattilio * owner is adaptively spinning on the 741194317Sattilio * interlock itself. 742194317Sattilio */ 743194317Sattilio if (flags & LK_INTERLOCK) { 744194317Sattilio class->lc_unlock(ilk); 745194317Sattilio flags &= ~LK_INTERLOCK; 746194317Sattilio } 747194317Sattilio GIANT_SAVE(); 748194317Sattilio while (LK_HOLDER(lk->lk_lock) == 749194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 750194317Sattilio cpu_spinwait(); 751196772Sattilio GIANT_RESTORE(); 752196772Sattilio continue; 753194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 754194317Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 755194317Sattilio spintries < alk_retries) { 756194317Sattilio if ((x & LK_EXCLUSIVE_SPINNERS) == 0 && 757194317Sattilio !atomic_cmpset_ptr(&lk->lk_lock, x, 758194317Sattilio x | LK_EXCLUSIVE_SPINNERS)) 759194317Sattilio continue; 760194317Sattilio if (flags & LK_INTERLOCK) { 761194317Sattilio class->lc_unlock(ilk); 762194317Sattilio flags &= ~LK_INTERLOCK; 763194317Sattilio } 764194317Sattilio GIANT_SAVE(); 765194317Sattilio spintries++; 766194317Sattilio for (i = 0; i < alk_loops; i++) { 767194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 768194317Sattilio CTR4(KTR_LOCK, 769194317Sattilio "%s: shared spinning on %p with %u and %u", 770194317Sattilio __func__, lk, spintries, i); 771194317Sattilio if ((lk->lk_lock & 772194317Sattilio LK_EXCLUSIVE_SPINNERS) == 0) 773194317Sattilio break; 774194317Sattilio cpu_spinwait(); 775194317Sattilio } 776196772Sattilio GIANT_RESTORE(); 777194317Sattilio if (i != alk_loops) 778194317Sattilio continue; 779194317Sattilio } 780194317Sattilio#endif 781194317Sattilio 782194317Sattilio /* 783177957Sattilio * Acquire the sleepqueue chain lock because we 784177957Sattilio * probabilly will need to manipulate waiters flags. 785177957Sattilio */ 786177957Sattilio sleepq_lock(&lk->lock_object); 787177957Sattilio x = lk->lk_lock; 788177957Sattilio 789177957Sattilio /* 790177957Sattilio * if the lock has been released while we spun on 791177957Sattilio * the sleepqueue chain lock just try again. 792177957Sattilio */ 793177957Sattilio if (x == LK_UNLOCKED) { 794177957Sattilio sleepq_release(&lk->lock_object); 795177957Sattilio continue; 796134365Skan } 79724269Speter 798194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 79924269Speter /* 800194317Sattilio * The current lock owner might have started executing 801194317Sattilio * on another CPU (or the lock could have changed 802194317Sattilio * owner) while we were waiting on the turnstile 803194317Sattilio * chain lock. If so, drop the turnstile lock and try 804194317Sattilio * again. 805194317Sattilio */ 806194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 807194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 808194317Sattilio owner = (struct thread *)LK_HOLDER(x); 809194317Sattilio if (TD_IS_RUNNING(owner)) { 810194317Sattilio sleepq_release(&lk->lock_object); 811194317Sattilio continue; 812194317Sattilio } 813194317Sattilio } 814194317Sattilio#endif 815194317Sattilio 816194317Sattilio /* 817177957Sattilio * The lock can be in the state where there is a 818177957Sattilio * pending queue of waiters, but still no owner. 819177957Sattilio * This happens when the lock is contested and an 820177957Sattilio * owner is going to claim the lock. 821177957Sattilio * If curthread is the one successfully acquiring it 822177957Sattilio * claim lock ownership and return, preserving waiters 823177957Sattilio * flags. 82424269Speter */ 825194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 826194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 827194317Sattilio v &= ~LK_EXCLUSIVE_SPINNERS; 828177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 829177957Sattilio tid | v)) { 830177957Sattilio sleepq_release(&lk->lock_object); 831177957Sattilio LOCK_LOG2(lk, 832177957Sattilio "%s: %p claimed by a new writer", 833177957Sattilio __func__, lk); 834177957Sattilio break; 835177957Sattilio } 836177957Sattilio sleepq_release(&lk->lock_object); 837177957Sattilio continue; 838177957Sattilio } 839177957Sattilio 840177957Sattilio /* 841177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 842177957Sattilio * fail, loop back and retry. 843177957Sattilio */ 844177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 845177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 846177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 847177957Sattilio sleepq_release(&lk->lock_object); 848177957Sattilio continue; 849177957Sattilio } 850177957Sattilio LOCK_LOG2(lk, "%s: %p set excl waiters flag", 851177957Sattilio __func__, lk); 852177957Sattilio } 853177957Sattilio 854177957Sattilio /* 855177957Sattilio * As far as we have been unable to acquire the 856177957Sattilio * exclusive lock and the exclusive waiters flag 857177957Sattilio * is set, we will sleep. 858177957Sattilio */ 859177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 860177957Sattilio SQ_EXCLUSIVE_QUEUE); 861177957Sattilio flags &= ~LK_INTERLOCK; 862177957Sattilio if (error) { 863177957Sattilio LOCK_LOG3(lk, 864177957Sattilio "%s: interrupted sleep for %p with %d", 865177957Sattilio __func__, lk, error); 86648301Smckusick break; 86748301Smckusick } 868177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 869177957Sattilio __func__, lk); 87024269Speter } 871177957Sattilio if (error == 0) { 872177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 873177957Sattilio contested, waittime, file, line); 874177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 875177957Sattilio lk->lk_recurse, file, line); 876178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 877178159Sattilio LK_TRYWIT(flags), file, line); 878177957Sattilio TD_LOCKS_INC(curthread); 879177957Sattilio STACK_SAVE(lk); 880177957Sattilio } 881177957Sattilio break; 882177957Sattilio case LK_DOWNGRADE: 883177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 884178159Sattilio LOCK_LOG_LOCK("XDOWNGRADE", &lk->lock_object, 0, 0, file, line); 885178159Sattilio WITNESS_DOWNGRADE(&lk->lock_object, 0, file, line); 886178159Sattilio TD_SLOCKS_INC(curthread); 887177957Sattilio 88824269Speter /* 889177957Sattilio * In order to preserve waiters flags, just spin. 89024269Speter */ 891177957Sattilio for (;;) { 892194317Sattilio x = lk->lk_lock; 893194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 894194317Sattilio x &= LK_ALL_WAITERS; 895177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 896178159Sattilio LK_SHARERS_LOCK(1) | x)) 897177957Sattilio break; 898177957Sattilio cpu_spinwait(); 89924269Speter } 90024269Speter break; 901177957Sattilio case LK_RELEASE: 902177957Sattilio _lockmgr_assert(lk, KA_LOCKED, file, line); 903177957Sattilio x = lk->lk_lock; 90424269Speter 905177957Sattilio if ((x & LK_SHARE) == 0) { 906177957Sattilio 907177957Sattilio /* 908177957Sattilio * As first option, treact the lock as if it has not 909177957Sattilio * any waiter. 910177957Sattilio * Fix-up the tid var if the lock has been disowned. 911177957Sattilio */ 912177957Sattilio if (LK_HOLDER(x) == LK_KERNPROC) 913177957Sattilio tid = LK_KERNPROC; 914178159Sattilio else { 915178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, 916178159Sattilio file, line); 917177957Sattilio TD_LOCKS_DEC(curthread); 918178159Sattilio } 919177957Sattilio LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, 920177957Sattilio lk->lk_recurse, file, line); 921177957Sattilio 922177957Sattilio /* 923177957Sattilio * The lock is held in exclusive mode. 924177957Sattilio * If the lock is recursed also, then unrecurse it. 925177957Sattilio */ 926177957Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) { 927177957Sattilio LOCK_LOG2(lk, "%s: %p unrecursing", __func__, 928177957Sattilio lk); 929177957Sattilio lk->lk_recurse--; 930177957Sattilio break; 931176014Sattilio } 932189788Sjeff if (tid != LK_KERNPROC) 933189788Sjeff lock_profile_release_lock(&lk->lock_object); 934177957Sattilio 935177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid, 936177957Sattilio LK_UNLOCKED)) 937177957Sattilio break; 938177957Sattilio 939177957Sattilio sleepq_lock(&lk->lock_object); 940194317Sattilio x = lk->lk_lock; 941177957Sattilio v = LK_UNLOCKED; 942177957Sattilio 943177957Sattilio /* 944177957Sattilio * If the lock has exclusive waiters, give them 945177957Sattilio * preference in order to avoid deadlock with 946177957Sattilio * shared runners up. 947200447Sattilio * If interruptible sleeps left the exclusive queue 948200447Sattilio * empty avoid a starvation for the threads sleeping 949200447Sattilio * on the shared queue by giving them precedence 950200447Sattilio * and cleaning up the exclusive waiters bit anyway. 951201709Sattilio * Please note that lk_exslpfail count may be lying 952201709Sattilio * about the real number of waiters with the 953201709Sattilio * LK_SLEEPFAIL flag on because they may be used in 954201709Sattilio * conjuction with interruptible sleeps so 955201709Sattilio * lk_exslpfail is consider as a 'upper limit' bound, 956201709Sattilio * considering the edge cases. 957177957Sattilio */ 958194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 959200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 960200447Sattilio SQ_EXCLUSIVE_QUEUE); 961200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 962200447Sattilio if (lk->lk_exslpfail < realexslp) { 963200447Sattilio lk->lk_exslpfail = 0; 964200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 965200447Sattilio v |= (x & LK_SHARED_WAITERS); 966200447Sattilio } else { 967200447Sattilio lk->lk_exslpfail = 0; 968200447Sattilio LOCK_LOG2(lk, 969200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 970200447Sattilio __func__, lk); 971200447Sattilio LOCK_LOG2(lk, 972200447Sattilio "%s: %p waking up threads on the exclusive queue", 973200447Sattilio __func__, lk); 974200447Sattilio wakeup_swapper = 975200447Sattilio sleepq_broadcast(&lk->lock_object, 976200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 977200447Sattilio queue = SQ_SHARED_QUEUE; 978200447Sattilio } 979177957Sattilio } else { 980201703Sattilio 981201703Sattilio /* 982201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL 983201703Sattilio * on and using interruptible sleeps/timeout 984201703Sattilio * may have left spourious lk_exslpfail counts 985201703Sattilio * on, so clean it up anyway. 986201703Sattilio */ 987201703Sattilio lk->lk_exslpfail = 0; 988177957Sattilio queue = SQ_SHARED_QUEUE; 98924269Speter } 990149723Sssouhlal 991177957Sattilio LOCK_LOG3(lk, 992177957Sattilio "%s: %p waking up threads on the %s queue", 993177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 994177957Sattilio "exclusive"); 995177957Sattilio atomic_store_rel_ptr(&lk->lk_lock, v); 996200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, 997181334Sjhb SLEEPQ_LK, 0, queue); 998177957Sattilio sleepq_release(&lk->lock_object); 999177957Sattilio break; 1000177957Sattilio } else 1001181334Sjhb wakeup_swapper = wakeupshlk(lk, file, line); 100224269Speter break; 1003177957Sattilio case LK_DRAIN: 1004178159Sattilio if (LK_CAN_WITNESS(flags)) 1005178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 1006182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 100724269Speter 100824269Speter /* 1009180798Skib * Trying to drain a lock we already own will result in a 1010177957Sattilio * deadlock. 101124269Speter */ 1012177957Sattilio if (lockmgr_xlocked(lk)) { 1013177957Sattilio if (flags & LK_INTERLOCK) 1014177957Sattilio class->lc_unlock(ilk); 1015177957Sattilio panic("%s: draining %s with the lock held @ %s:%d\n", 1016177957Sattilio __func__, iwmesg, file, line); 1017177957Sattilio } 101828345Sdyson 1019177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) { 1020177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 1021177957Sattilio &contested, &waittime); 102224269Speter 1023177957Sattilio /* 1024177957Sattilio * If the lock is expected to not sleep just give up 1025177957Sattilio * and return. 1026177957Sattilio */ 1027177957Sattilio if (LK_TRYOP(flags)) { 1028177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 1029177957Sattilio __func__, lk); 1030177957Sattilio error = EBUSY; 1031177957Sattilio break; 1032177957Sattilio } 103324269Speter 1034177957Sattilio /* 1035177957Sattilio * Acquire the sleepqueue chain lock because we 1036177957Sattilio * probabilly will need to manipulate waiters flags. 1037177957Sattilio */ 1038177957Sattilio sleepq_lock(&lk->lock_object); 1039177957Sattilio x = lk->lk_lock; 104029653Sdyson 1041177957Sattilio /* 1042177957Sattilio * if the lock has been released while we spun on 1043177957Sattilio * the sleepqueue chain lock just try again. 1044177957Sattilio */ 1045177957Sattilio if (x == LK_UNLOCKED) { 1046177957Sattilio sleepq_release(&lk->lock_object); 1047177957Sattilio continue; 1048177957Sattilio } 1049176320Sattilio 1050194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 1051194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 1052194317Sattilio v = (x & ~LK_EXCLUSIVE_SPINNERS); 1053200447Sattilio 1054200447Sattilio /* 1055200447Sattilio * If interruptible sleeps left the exclusive 1056200447Sattilio * queue empty avoid a starvation for the 1057200447Sattilio * threads sleeping on the shared queue by 1058200447Sattilio * giving them precedence and cleaning up the 1059200447Sattilio * exclusive waiters bit anyway. 1060201709Sattilio * Please note that lk_exslpfail count may be 1061201709Sattilio * lying about the real number of waiters with 1062201709Sattilio * the LK_SLEEPFAIL flag on because they may 1063201709Sattilio * be used in conjuction with interruptible 1064201709Sattilio * sleeps so lk_exslpfail is consider as a 1065201709Sattilio * 'upper limit' bound, considering the edge 1066201709Sattilio * cases. 1067200447Sattilio */ 1068177957Sattilio if (v & LK_EXCLUSIVE_WAITERS) { 1069177957Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1070177957Sattilio v &= ~LK_EXCLUSIVE_WAITERS; 1071177957Sattilio } else { 1072201703Sattilio 1073201703Sattilio /* 1074201703Sattilio * Exclusive waiters sleeping with 1075201703Sattilio * LK_SLEEPFAIL on and using 1076201703Sattilio * interruptible sleeps/timeout may 1077201703Sattilio * have left spourious lk_exslpfail 1078201703Sattilio * counts on, so clean it up anyway. 1079201703Sattilio */ 1080177957Sattilio MPASS(v & LK_SHARED_WAITERS); 1081201703Sattilio lk->lk_exslpfail = 0; 1082177957Sattilio queue = SQ_SHARED_QUEUE; 1083177957Sattilio v &= ~LK_SHARED_WAITERS; 1084177957Sattilio } 1085200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE) { 1086200447Sattilio realexslp = 1087200447Sattilio sleepq_sleepcnt(&lk->lock_object, 1088200447Sattilio SQ_EXCLUSIVE_QUEUE); 1089200447Sattilio if (lk->lk_exslpfail >= realexslp) { 1090200447Sattilio lk->lk_exslpfail = 0; 1091200447Sattilio queue = SQ_SHARED_QUEUE; 1092200447Sattilio v &= ~LK_SHARED_WAITERS; 1093200447Sattilio if (realexslp != 0) { 1094200447Sattilio LOCK_LOG2(lk, 1095200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1096200447Sattilio __func__, lk); 1097200447Sattilio LOCK_LOG2(lk, 1098200447Sattilio "%s: %p waking up threads on the exclusive queue", 1099200447Sattilio __func__, lk); 1100200447Sattilio wakeup_swapper = 1101200447Sattilio sleepq_broadcast( 1102200447Sattilio &lk->lock_object, 1103200447Sattilio SLEEPQ_LK, 0, 1104200447Sattilio SQ_EXCLUSIVE_QUEUE); 1105200447Sattilio } 1106200447Sattilio } else 1107200447Sattilio lk->lk_exslpfail = 0; 1108200447Sattilio } 1109177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, v)) { 1110177957Sattilio sleepq_release(&lk->lock_object); 1111177957Sattilio continue; 1112177957Sattilio } 1113177957Sattilio LOCK_LOG3(lk, 1114177957Sattilio "%s: %p waking up all threads on the %s queue", 1115177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? 1116177957Sattilio "shared" : "exclusive"); 1117182010Sjhb wakeup_swapper |= sleepq_broadcast( 1118181334Sjhb &lk->lock_object, SLEEPQ_LK, 0, queue); 1119177957Sattilio 1120177957Sattilio /* 1121177957Sattilio * If shared waiters have been woken up we need 1122177957Sattilio * to wait for one of them to acquire the lock 1123177957Sattilio * before to set the exclusive waiters in 1124177957Sattilio * order to avoid a deadlock. 1125177957Sattilio */ 1126177957Sattilio if (queue == SQ_SHARED_QUEUE) { 1127177957Sattilio for (v = lk->lk_lock; 1128177957Sattilio (v & LK_SHARE) && !LK_SHARERS(v); 1129177957Sattilio v = lk->lk_lock) 1130177957Sattilio cpu_spinwait(); 1131177957Sattilio } 1132177957Sattilio } 1133177957Sattilio 1134177957Sattilio /* 1135177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 1136177957Sattilio * fail, loop back and retry. 1137177957Sattilio */ 1138177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 1139177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 1140177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 1141177957Sattilio sleepq_release(&lk->lock_object); 1142177957Sattilio continue; 1143177957Sattilio } 1144177957Sattilio LOCK_LOG2(lk, "%s: %p set drain waiters flag", 1145177957Sattilio __func__, lk); 1146177957Sattilio } 1147177957Sattilio 1148177957Sattilio /* 1149177957Sattilio * As far as we have been unable to acquire the 1150177957Sattilio * exclusive lock and the exclusive waiters flag 1151177957Sattilio * is set, we will sleep. 1152177957Sattilio */ 1153177957Sattilio if (flags & LK_INTERLOCK) { 1154177957Sattilio class->lc_unlock(ilk); 1155177957Sattilio flags &= ~LK_INTERLOCK; 1156177957Sattilio } 1157178159Sattilio GIANT_SAVE(); 1158177957Sattilio sleepq_add(&lk->lock_object, NULL, iwmesg, SLEEPQ_LK, 1159177957Sattilio SQ_EXCLUSIVE_QUEUE); 1160177957Sattilio sleepq_wait(&lk->lock_object, ipri & PRIMASK); 1161178159Sattilio GIANT_RESTORE(); 1162177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 1163177957Sattilio __func__, lk); 116429653Sdyson } 1165177957Sattilio 1166177957Sattilio if (error == 0) { 1167177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 1168177957Sattilio contested, waittime, file, line); 1169177957Sattilio LOCK_LOG_LOCK("DRAIN", &lk->lock_object, 0, 1170177957Sattilio lk->lk_recurse, file, line); 1171178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 1172178159Sattilio LK_TRYWIT(flags), file, line); 1173177957Sattilio TD_LOCKS_INC(curthread); 1174177957Sattilio STACK_SAVE(lk); 1175177957Sattilio } 1176177957Sattilio break; 1177177957Sattilio default: 1178177957Sattilio if (flags & LK_INTERLOCK) 1179177957Sattilio class->lc_unlock(ilk); 1180177957Sattilio panic("%s: unknown lockmgr request 0x%x\n", __func__, op); 118129653Sdyson } 1182177957Sattilio 1183177957Sattilio if (flags & LK_INTERLOCK) 1184177957Sattilio class->lc_unlock(ilk); 1185181334Sjhb if (wakeup_swapper) 1186181334Sjhb kick_proc0(); 1187177957Sattilio 1188177957Sattilio return (error); 118929653Sdyson} 119029653Sdyson 119129653Sdysonvoid 1192177957Sattilio_lockmgr_disown(struct lock *lk, const char *file, int line) 119329653Sdyson{ 1194177957Sattilio uintptr_t tid, x; 1195176014Sattilio 1196177957Sattilio tid = (uintptr_t)curthread; 1197177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 119829653Sdyson 1199177957Sattilio /* 1200180798Skib * If the owner is already LK_KERNPROC just skip the whole operation. 1201177957Sattilio */ 1202177957Sattilio if (LK_HOLDER(lk->lk_lock) != tid) 1203177957Sattilio return; 1204189788Sjeff lock_profile_release_lock(&lk->lock_object); 1205178159Sattilio LOCK_LOG_LOCK("XDISOWN", &lk->lock_object, 0, 0, file, line); 1206178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); 1207178159Sattilio TD_LOCKS_DEC(curthread); 1208199008Sattilio STACK_SAVE(lk); 120929653Sdyson 1210177957Sattilio /* 1211177957Sattilio * In order to preserve waiters flags, just spin. 1212177957Sattilio */ 1213177957Sattilio for (;;) { 1214194317Sattilio x = lk->lk_lock; 1215194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1216194317Sattilio x &= LK_ALL_WAITERS; 1217178166Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 1218178159Sattilio LK_KERNPROC | x)) 1219177957Sattilio return; 1220177957Sattilio cpu_spinwait(); 1221177957Sattilio } 122266615Sjasone} 122366615Sjasone 1224175166Sattiliovoid 1225177957Sattiliolockmgr_printinfo(struct lock *lk) 1226175166Sattilio{ 1227175166Sattilio struct thread *td; 1228177957Sattilio uintptr_t x; 1229175166Sattilio 1230177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1231188244Sjhb printf("lock type %s: UNLOCKED\n", lk->lock_object.lo_name); 1232177957Sattilio else if (lk->lk_lock & LK_SHARE) 1233188244Sjhb printf("lock type %s: SHARED (count %ju)\n", 1234177957Sattilio lk->lock_object.lo_name, 1235177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1236177957Sattilio else { 1237177957Sattilio td = lockmgr_xholder(lk); 1238188244Sjhb printf("lock type %s: EXCL by thread %p (pid %d)\n", 1239177957Sattilio lk->lock_object.lo_name, td, td->td_proc->p_pid); 1240177957Sattilio } 1241175166Sattilio 1242177957Sattilio x = lk->lk_lock; 1243177957Sattilio if (x & LK_EXCLUSIVE_WAITERS) 1244177957Sattilio printf(" with exclusive waiters pending\n"); 1245177957Sattilio if (x & LK_SHARED_WAITERS) 1246177957Sattilio printf(" with shared waiters pending\n"); 1247194317Sattilio if (x & LK_EXCLUSIVE_SPINNERS) 1248194317Sattilio printf(" with exclusive spinners pending\n"); 1249177957Sattilio 1250177957Sattilio STACK_PRINT(lk); 1251175166Sattilio} 1252175166Sattilio 125329653Sdysonint 1254177957Sattiliolockstatus(struct lock *lk) 125529653Sdyson{ 1256177957Sattilio uintptr_t v, x; 1257177957Sattilio int ret; 125829653Sdyson 1259177957Sattilio ret = LK_SHARED; 1260177957Sattilio x = lk->lk_lock; 1261177957Sattilio v = LK_HOLDER(x); 1262175635Sattilio 1263177957Sattilio if ((x & LK_SHARE) == 0) { 1264177957Sattilio if (v == (uintptr_t)curthread || v == LK_KERNPROC) 1265177957Sattilio ret = LK_EXCLUSIVE; 126654444Seivind else 1267177957Sattilio ret = LK_EXCLOTHER; 1268177957Sattilio } else if (x == LK_UNLOCKED) 1269177957Sattilio ret = 0; 127029653Sdyson 1271177957Sattilio return (ret); 127224269Speter} 1273161322Sjhb 1274176249Sattilio#ifdef INVARIANT_SUPPORT 1275176249Sattilio#ifndef INVARIANTS 1276177957Sattilio#undef _lockmgr_assert 1277176249Sattilio#endif 1278176249Sattilio 1279176249Sattiliovoid 1280177957Sattilio_lockmgr_assert(struct lock *lk, int what, const char *file, int line) 1281176249Sattilio{ 1282176249Sattilio int slocked = 0; 1283176249Sattilio 1284176249Sattilio if (panicstr != NULL) 1285176249Sattilio return; 1286176249Sattilio switch (what) { 1287176249Sattilio case KA_SLOCKED: 1288176249Sattilio case KA_SLOCKED | KA_NOTRECURSED: 1289176249Sattilio case KA_SLOCKED | KA_RECURSED: 1290176249Sattilio slocked = 1; 1291176249Sattilio case KA_LOCKED: 1292176249Sattilio case KA_LOCKED | KA_NOTRECURSED: 1293176249Sattilio case KA_LOCKED | KA_RECURSED: 1294178159Sattilio#ifdef WITNESS 1295178159Sattilio 1296178159Sattilio /* 1297178159Sattilio * We cannot trust WITNESS if the lock is held in exclusive 1298178159Sattilio * mode and a call to lockmgr_disown() happened. 1299178159Sattilio * Workaround this skipping the check if the lock is held in 1300178159Sattilio * exclusive mode even for the KA_LOCKED case. 1301178159Sattilio */ 1302178159Sattilio if (slocked || (lk->lk_lock & LK_SHARE)) { 1303178159Sattilio witness_assert(&lk->lock_object, what, file, line); 1304178159Sattilio break; 1305178159Sattilio } 1306178159Sattilio#endif 1307177957Sattilio if (lk->lk_lock == LK_UNLOCKED || 1308177957Sattilio ((lk->lk_lock & LK_SHARE) == 0 && (slocked || 1309177957Sattilio (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk))))) 1310176249Sattilio panic("Lock %s not %slocked @ %s:%d\n", 1311177957Sattilio lk->lock_object.lo_name, slocked ? "share" : "", 1312176249Sattilio file, line); 1313177957Sattilio 1314177957Sattilio if ((lk->lk_lock & LK_SHARE) == 0) { 1315177957Sattilio if (lockmgr_recursed(lk)) { 1316176249Sattilio if (what & KA_NOTRECURSED) 1317176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1318177957Sattilio lk->lock_object.lo_name, file, 1319177957Sattilio line); 1320176249Sattilio } else if (what & KA_RECURSED) 1321176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1322177957Sattilio lk->lock_object.lo_name, file, line); 1323176249Sattilio } 1324176249Sattilio break; 1325176249Sattilio case KA_XLOCKED: 1326176249Sattilio case KA_XLOCKED | KA_NOTRECURSED: 1327176249Sattilio case KA_XLOCKED | KA_RECURSED: 1328177957Sattilio if (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk)) 1329176249Sattilio panic("Lock %s not exclusively locked @ %s:%d\n", 1330177957Sattilio lk->lock_object.lo_name, file, line); 1331177957Sattilio if (lockmgr_recursed(lk)) { 1332176249Sattilio if (what & KA_NOTRECURSED) 1333176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1334177957Sattilio lk->lock_object.lo_name, file, line); 1335176249Sattilio } else if (what & KA_RECURSED) 1336176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1337177957Sattilio lk->lock_object.lo_name, file, line); 1338176249Sattilio break; 1339176249Sattilio case KA_UNLOCKED: 1340177957Sattilio if (lockmgr_xlocked(lk) || lockmgr_disowned(lk)) 1341176249Sattilio panic("Lock %s exclusively locked @ %s:%d\n", 1342177957Sattilio lk->lock_object.lo_name, file, line); 1343176249Sattilio break; 1344176249Sattilio default: 1345177957Sattilio panic("Unknown lockmgr assertion: %d @ %s:%d\n", what, file, 1346177957Sattilio line); 1347176249Sattilio } 1348176249Sattilio} 1349177957Sattilio#endif 1350176249Sattilio 1351161322Sjhb#ifdef DDB 1352161337Sjhbint 1353161337Sjhblockmgr_chain(struct thread *td, struct thread **ownerp) 1354161337Sjhb{ 1355177957Sattilio struct lock *lk; 1356161337Sjhb 1357177957Sattilio lk = td->td_wchan; 1358161337Sjhb 1359177957Sattilio if (LOCK_CLASS(&lk->lock_object) != &lock_class_lockmgr) 1360177957Sattilio return (0); 1361177957Sattilio db_printf("blocked on lockmgr %s", lk->lock_object.lo_name); 1362177957Sattilio if (lk->lk_lock & LK_SHARE) 1363177957Sattilio db_printf("SHARED (count %ju)\n", 1364177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1365177957Sattilio else 1366177957Sattilio db_printf("EXCL\n"); 1367177957Sattilio *ownerp = lockmgr_xholder(lk); 1368161337Sjhb 1369161337Sjhb return (1); 1370161337Sjhb} 1371161337Sjhb 1372177957Sattiliostatic void 1373164246Skmacydb_show_lockmgr(struct lock_object *lock) 1374161322Sjhb{ 1375161322Sjhb struct thread *td; 1376177957Sattilio struct lock *lk; 1377161322Sjhb 1378177957Sattilio lk = (struct lock *)lock; 1379161322Sjhb 1380168070Sjhb db_printf(" state: "); 1381177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1382161322Sjhb db_printf("UNLOCKED\n"); 1383177957Sattilio else if (lk->lk_lock & LK_SHARE) 1384177957Sattilio db_printf("SLOCK: %ju\n", (uintmax_t)LK_SHARERS(lk->lk_lock)); 1385177957Sattilio else { 1386177957Sattilio td = lockmgr_xholder(lk); 1387177957Sattilio if (td == (struct thread *)LK_KERNPROC) 1388177957Sattilio db_printf("XLOCK: LK_KERNPROC\n"); 1389177957Sattilio else 1390177957Sattilio db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td, 1391177957Sattilio td->td_tid, td->td_proc->p_pid, 1392177957Sattilio td->td_proc->p_comm); 1393177957Sattilio if (lockmgr_recursed(lk)) 1394177957Sattilio db_printf(" recursed: %d\n", lk->lk_recurse); 1395177957Sattilio } 1396177957Sattilio db_printf(" waiters: "); 1397177957Sattilio switch (lk->lk_lock & LK_ALL_WAITERS) { 1398177957Sattilio case LK_SHARED_WAITERS: 1399177957Sattilio db_printf("shared\n"); 1400192022Strasz break; 1401177957Sattilio case LK_EXCLUSIVE_WAITERS: 1402177957Sattilio db_printf("exclusive\n"); 1403177957Sattilio break; 1404177957Sattilio case LK_ALL_WAITERS: 1405177957Sattilio db_printf("shared and exclusive\n"); 1406177957Sattilio break; 1407177957Sattilio default: 1408177957Sattilio db_printf("none\n"); 1409177957Sattilio } 1410194317Sattilio db_printf(" spinners: "); 1411194317Sattilio if (lk->lk_lock & LK_EXCLUSIVE_SPINNERS) 1412194317Sattilio db_printf("exclusive\n"); 1413194317Sattilio else 1414194317Sattilio db_printf("none\n"); 1415161322Sjhb} 1416161322Sjhb#endif 1417