kern_lock.c revision 211531
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 211531 2010-08-20 19:46:50Z jhb $"); 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 283201710Sattilio * sleeps so lk_exslpfail might be considered an 'upper limit' 284201710Sattilio * bound, including 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 399211531Sjhb/* 400211531Sjhb * XXX: Gross hacks to manipulate external lock flags after 401211531Sjhb * initialization. Used for certain vnode and buf locks. 402211531Sjhb */ 403177957Sattiliovoid 404211531Sjhblockallowshare(struct lock *lk) 405211531Sjhb{ 406211531Sjhb 407211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 408211531Sjhb lk->lock_object.lo_flags &= ~LK_NOSHARE; 409211531Sjhb} 410211531Sjhb 411211531Sjhbvoid 412211531Sjhblockallowrecurse(struct lock *lk) 413211531Sjhb{ 414211531Sjhb 415211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 416211531Sjhb lk->lock_object.lo_flags |= LO_RECURSABLE; 417211531Sjhb} 418211531Sjhb 419211531Sjhbvoid 420211531Sjhblockdisablerecurse(struct lock *lk) 421211531Sjhb{ 422211531Sjhb 423211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 424211531Sjhb lk->lock_object.lo_flags &= ~LO_RECURSABLE; 425211531Sjhb} 426211531Sjhb 427211531Sjhbvoid 428177957Sattiliolockdestroy(struct lock *lk) 429177957Sattilio{ 43042453Seivind 431177957Sattilio KASSERT(lk->lk_lock == LK_UNLOCKED, ("lockmgr still held")); 432177957Sattilio KASSERT(lk->lk_recurse == 0, ("lockmgr still recursed")); 433200447Sattilio KASSERT(lk->lk_exslpfail == 0, ("lockmgr still exclusive waiters")); 434177957Sattilio lock_destroy(&lk->lock_object); 43528345Sdyson} 43628345Sdyson 437177957Sattilioint 438177957Sattilio__lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, 439177957Sattilio const char *wmesg, int pri, int timo, const char *file, int line) 440140711Sjeff{ 441178159Sattilio GIANT_DECLARE; 442177957Sattilio struct lock_class *class; 443176320Sattilio const char *iwmesg; 444177957Sattilio uintptr_t tid, v, x; 445200447Sattilio u_int op, realexslp; 446189846Sjeff int error, ipri, itimo, queue, wakeup_swapper; 447189846Sjeff#ifdef LOCK_PROFILING 448189846Sjeff uint64_t waittime = 0; 449189846Sjeff int contested = 0; 450189846Sjeff#endif 451194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 452194317Sattilio volatile struct thread *owner; 453194317Sattilio u_int i, spintries = 0; 454194317Sattilio#endif 455176320Sattilio 456177957Sattilio error = 0; 457177957Sattilio tid = (uintptr_t)curthread; 458177957Sattilio op = (flags & LK_TYPE_MASK); 459177957Sattilio iwmesg = (wmesg == LK_WMESG_DEFAULT) ? lk->lock_object.lo_name : wmesg; 460177957Sattilio ipri = (pri == LK_PRIO_DEFAULT) ? lk->lk_pri : pri; 461177957Sattilio itimo = (timo == LK_TIMO_DEFAULT) ? lk->lk_timo : timo; 462176320Sattilio 463177957Sattilio MPASS((flags & ~LK_TOTAL_MASK) == 0); 464178150Sattilio KASSERT((op & (op - 1)) == 0, 465178150Sattilio ("%s: Invalid requested operation @ %s:%d", __func__, file, line)); 466177957Sattilio KASSERT((flags & (LK_NOWAIT | LK_SLEEPFAIL)) == 0 || 467177957Sattilio (op != LK_DOWNGRADE && op != LK_RELEASE), 468177957Sattilio ("%s: Invalid flags in regard of the operation desired @ %s:%d", 469177957Sattilio __func__, file, line)); 470177957Sattilio KASSERT((flags & LK_INTERLOCK) == 0 || ilk != NULL, 471177957Sattilio ("%s: LK_INTERLOCK passed without valid interlock @ %s:%d", 472177957Sattilio __func__, file, line)); 47366615Sjasone 474177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 475177957Sattilio if (panicstr != NULL) { 476177957Sattilio if (flags & LK_INTERLOCK) 477177957Sattilio class->lc_unlock(ilk); 478177957Sattilio return (0); 47928345Sdyson } 48028345Sdyson 481177957Sattilio if (op == LK_SHARED && (lk->lock_object.lo_flags & LK_NOSHARE)) 482177957Sattilio op = LK_EXCLUSIVE; 483164159Skmacy 484181334Sjhb wakeup_swapper = 0; 485177957Sattilio switch (op) { 486177957Sattilio case LK_SHARED: 487178159Sattilio if (LK_CAN_WITNESS(flags)) 488178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, 489182914Sjhb file, line, ilk); 490177957Sattilio for (;;) { 491177957Sattilio x = lk->lk_lock; 492174948Sattilio 493177957Sattilio /* 494177957Sattilio * If no other thread has an exclusive lock, or 495177957Sattilio * no exclusive waiter is present, bump the count of 496177957Sattilio * sharers. Since we have to preserve the state of 497177957Sattilio * waiters, if we fail to acquire the shared lock 498177957Sattilio * loop back and retry. 499177957Sattilio */ 500177957Sattilio if (LK_CAN_SHARE(x)) { 501177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 502177957Sattilio x + LK_ONE_SHARER)) 503177957Sattilio break; 504177957Sattilio continue; 505177957Sattilio } 506177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 507177957Sattilio &contested, &waittime); 50828345Sdyson 509177957Sattilio /* 510180798Skib * If the lock is already held by curthread in 511177957Sattilio * exclusive way avoid a deadlock. 512177957Sattilio */ 513177957Sattilio if (LK_HOLDER(x) == tid) { 514177957Sattilio LOCK_LOG2(lk, 515180798Skib "%s: %p already held in exclusive mode", 516177957Sattilio __func__, lk); 517177957Sattilio error = EDEADLK; 518177957Sattilio break; 519177957Sattilio } 520140711Sjeff 521177957Sattilio /* 522177957Sattilio * If the lock is expected to not sleep just give up 523177957Sattilio * and return. 524177957Sattilio */ 525177957Sattilio if (LK_TRYOP(flags)) { 526177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 527177957Sattilio __func__, lk); 528177957Sattilio error = EBUSY; 529177957Sattilio break; 530177957Sattilio } 53128345Sdyson 532194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 533177957Sattilio /* 534194317Sattilio * If the owner is running on another CPU, spin until 535194317Sattilio * the owner stops running or the state of the lock 536196772Sattilio * changes. We need a double-state handle here 537196772Sattilio * because for a failed acquisition the lock can be 538196772Sattilio * either held in exclusive mode or shared mode 539196772Sattilio * (for the writer starvation avoidance technique). 540194317Sattilio */ 541194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 542194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 543194317Sattilio owner = (struct thread *)LK_HOLDER(x); 544194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 545194317Sattilio CTR3(KTR_LOCK, 546194317Sattilio "%s: spinning on %p held by %p", 547194317Sattilio __func__, lk, owner); 548194317Sattilio 549194317Sattilio /* 550194317Sattilio * If we are holding also an interlock drop it 551194317Sattilio * in order to avoid a deadlock if the lockmgr 552194317Sattilio * owner is adaptively spinning on the 553194317Sattilio * interlock itself. 554194317Sattilio */ 555194317Sattilio if (flags & LK_INTERLOCK) { 556194317Sattilio class->lc_unlock(ilk); 557194317Sattilio flags &= ~LK_INTERLOCK; 558194317Sattilio } 559194317Sattilio GIANT_SAVE(); 560194317Sattilio while (LK_HOLDER(lk->lk_lock) == 561194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 562194317Sattilio cpu_spinwait(); 563196772Sattilio GIANT_RESTORE(); 564196772Sattilio continue; 565194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 566196772Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 567194317Sattilio spintries < alk_retries) { 568194317Sattilio if (flags & LK_INTERLOCK) { 569194317Sattilio class->lc_unlock(ilk); 570194317Sattilio flags &= ~LK_INTERLOCK; 571194317Sattilio } 572194317Sattilio GIANT_SAVE(); 573194317Sattilio spintries++; 574194317Sattilio for (i = 0; i < alk_loops; i++) { 575194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 576194317Sattilio CTR4(KTR_LOCK, 577194317Sattilio "%s: shared spinning on %p with %u and %u", 578194317Sattilio __func__, lk, spintries, i); 579194317Sattilio x = lk->lk_lock; 580194317Sattilio if ((x & LK_SHARE) == 0 || 581194317Sattilio LK_CAN_SHARE(x) != 0) 582194317Sattilio break; 583194317Sattilio cpu_spinwait(); 584194317Sattilio } 585196772Sattilio GIANT_RESTORE(); 586194317Sattilio if (i != alk_loops) 587194317Sattilio continue; 588194317Sattilio } 589194317Sattilio#endif 590194317Sattilio 591194317Sattilio /* 592177957Sattilio * Acquire the sleepqueue chain lock because we 593177957Sattilio * probabilly will need to manipulate waiters flags. 594177957Sattilio */ 595177957Sattilio sleepq_lock(&lk->lock_object); 596177957Sattilio x = lk->lk_lock; 597111463Sjeff 598177957Sattilio /* 599177957Sattilio * if the lock can be acquired in shared mode, try 600177957Sattilio * again. 601177957Sattilio */ 602177957Sattilio if (LK_CAN_SHARE(x)) { 603177957Sattilio sleepq_release(&lk->lock_object); 604177957Sattilio continue; 605177957Sattilio } 60624269Speter 607194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 608177957Sattilio /* 609194317Sattilio * The current lock owner might have started executing 610194317Sattilio * on another CPU (or the lock could have changed 611194317Sattilio * owner) while we were waiting on the turnstile 612194317Sattilio * chain lock. If so, drop the turnstile lock and try 613194317Sattilio * again. 614194317Sattilio */ 615194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 616194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 617194317Sattilio owner = (struct thread *)LK_HOLDER(x); 618194317Sattilio if (TD_IS_RUNNING(owner)) { 619194317Sattilio sleepq_release(&lk->lock_object); 620194317Sattilio continue; 621194317Sattilio } 622194317Sattilio } 623194317Sattilio#endif 624194317Sattilio 625194317Sattilio /* 626177957Sattilio * Try to set the LK_SHARED_WAITERS flag. If we fail, 627177957Sattilio * loop back and retry. 628177957Sattilio */ 629177957Sattilio if ((x & LK_SHARED_WAITERS) == 0) { 630177957Sattilio if (!atomic_cmpset_acq_ptr(&lk->lk_lock, x, 631177957Sattilio x | LK_SHARED_WAITERS)) { 632177957Sattilio sleepq_release(&lk->lock_object); 633177957Sattilio continue; 634177957Sattilio } 635177957Sattilio LOCK_LOG2(lk, "%s: %p set shared waiters flag", 636177957Sattilio __func__, lk); 637177957Sattilio } 63824269Speter 639177957Sattilio /* 640177957Sattilio * As far as we have been unable to acquire the 641177957Sattilio * shared lock and the shared waiters flag is set, 642177957Sattilio * we will sleep. 643177957Sattilio */ 644177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 645177957Sattilio SQ_SHARED_QUEUE); 646177957Sattilio flags &= ~LK_INTERLOCK; 647177957Sattilio if (error) { 648177957Sattilio LOCK_LOG3(lk, 649177957Sattilio "%s: interrupted sleep for %p with %d", 650177957Sattilio __func__, lk, error); 651177957Sattilio break; 652177957Sattilio } 653177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 654177957Sattilio __func__, lk); 655177957Sattilio } 656177957Sattilio if (error == 0) { 657177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 658177957Sattilio contested, waittime, file, line); 659177957Sattilio LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, file, 660176014Sattilio line); 661178159Sattilio WITNESS_LOCK(&lk->lock_object, LK_TRYWIT(flags), file, 662178159Sattilio line); 663177957Sattilio TD_LOCKS_INC(curthread); 664177957Sattilio TD_SLOCKS_INC(curthread); 665177957Sattilio STACK_SAVE(lk); 666177957Sattilio } 667177957Sattilio break; 668177957Sattilio case LK_UPGRADE: 669177957Sattilio _lockmgr_assert(lk, KA_SLOCKED, file, line); 670194317Sattilio v = lk->lk_lock; 671194317Sattilio x = v & LK_ALL_WAITERS; 672194317Sattilio v &= LK_EXCLUSIVE_SPINNERS; 673177957Sattilio 67444681Sjulian /* 675177957Sattilio * Try to switch from one shared lock to an exclusive one. 676177957Sattilio * We need to preserve waiters flags during the operation. 67744681Sjulian */ 678194317Sattilio if (atomic_cmpset_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x | v, 679177957Sattilio tid | x)) { 680177957Sattilio LOCK_LOG_LOCK("XUPGRADE", &lk->lock_object, 0, 0, file, 681177957Sattilio line); 682178159Sattilio WITNESS_UPGRADE(&lk->lock_object, LOP_EXCLUSIVE | 683178159Sattilio LK_TRYWIT(flags), file, line); 684177957Sattilio TD_SLOCKS_DEC(curthread); 68524269Speter break; 68624269Speter } 687177957Sattilio 68824269Speter /* 689177957Sattilio * We have been unable to succeed in upgrading, so just 690177957Sattilio * give up the shared lock. 69124269Speter */ 692182010Sjhb wakeup_swapper |= wakeupshlk(lk, file, line); 69324269Speter 694177957Sattilio /* FALLTHROUGH */ 695177957Sattilio case LK_EXCLUSIVE: 696178159Sattilio if (LK_CAN_WITNESS(flags)) 697178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 698182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 69924269Speter 70024269Speter /* 701180798Skib * If curthread already holds the lock and this one is 702177957Sattilio * allowed to recurse, simply recurse on it. 70324269Speter */ 704177957Sattilio if (lockmgr_xlocked(lk)) { 705177957Sattilio if ((flags & LK_CANRECURSE) == 0 && 706193307Sattilio (lk->lock_object.lo_flags & LO_RECURSABLE) == 0) { 707177957Sattilio 708177957Sattilio /* 709177957Sattilio * If the lock is expected to not panic just 710177957Sattilio * give up and return. 711177957Sattilio */ 712177957Sattilio if (LK_TRYOP(flags)) { 713177957Sattilio LOCK_LOG2(lk, 714177957Sattilio "%s: %p fails the try operation", 715177957Sattilio __func__, lk); 716177957Sattilio error = EBUSY; 717177957Sattilio break; 718177957Sattilio } 719177957Sattilio if (flags & LK_INTERLOCK) 720177957Sattilio class->lc_unlock(ilk); 721177957Sattilio panic("%s: recursing on non recursive lockmgr %s @ %s:%d\n", 722177957Sattilio __func__, iwmesg, file, line); 723177957Sattilio } 724177957Sattilio lk->lk_recurse++; 725177957Sattilio LOCK_LOG2(lk, "%s: %p recursing", __func__, lk); 726177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 727177957Sattilio lk->lk_recurse, file, line); 728178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 729178159Sattilio LK_TRYWIT(flags), file, line); 730177957Sattilio TD_LOCKS_INC(curthread); 73124269Speter break; 73224269Speter } 733177957Sattilio 734177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, 735177957Sattilio tid)) { 736177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 737177957Sattilio &contested, &waittime); 738177957Sattilio 73924269Speter /* 740177957Sattilio * If the lock is expected to not sleep just give up 741177957Sattilio * and return. 74224269Speter */ 743177957Sattilio if (LK_TRYOP(flags)) { 744177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 745177957Sattilio __func__, lk); 746177957Sattilio error = EBUSY; 747177957Sattilio break; 748177957Sattilio } 74934194Sdyson 750194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 751177957Sattilio /* 752194317Sattilio * If the owner is running on another CPU, spin until 753194317Sattilio * the owner stops running or the state of the lock 754194317Sattilio * changes. 755194317Sattilio */ 756194317Sattilio x = lk->lk_lock; 757194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 758194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 759194317Sattilio owner = (struct thread *)LK_HOLDER(x); 760194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 761194317Sattilio CTR3(KTR_LOCK, 762194317Sattilio "%s: spinning on %p held by %p", 763194317Sattilio __func__, lk, owner); 764194317Sattilio 765194317Sattilio /* 766194317Sattilio * If we are holding also an interlock drop it 767194317Sattilio * in order to avoid a deadlock if the lockmgr 768194317Sattilio * owner is adaptively spinning on the 769194317Sattilio * interlock itself. 770194317Sattilio */ 771194317Sattilio if (flags & LK_INTERLOCK) { 772194317Sattilio class->lc_unlock(ilk); 773194317Sattilio flags &= ~LK_INTERLOCK; 774194317Sattilio } 775194317Sattilio GIANT_SAVE(); 776194317Sattilio while (LK_HOLDER(lk->lk_lock) == 777194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 778194317Sattilio cpu_spinwait(); 779196772Sattilio GIANT_RESTORE(); 780196772Sattilio continue; 781194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 782194317Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 783194317Sattilio spintries < alk_retries) { 784194317Sattilio if ((x & LK_EXCLUSIVE_SPINNERS) == 0 && 785194317Sattilio !atomic_cmpset_ptr(&lk->lk_lock, x, 786194317Sattilio x | LK_EXCLUSIVE_SPINNERS)) 787194317Sattilio continue; 788194317Sattilio if (flags & LK_INTERLOCK) { 789194317Sattilio class->lc_unlock(ilk); 790194317Sattilio flags &= ~LK_INTERLOCK; 791194317Sattilio } 792194317Sattilio GIANT_SAVE(); 793194317Sattilio spintries++; 794194317Sattilio for (i = 0; i < alk_loops; i++) { 795194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 796194317Sattilio CTR4(KTR_LOCK, 797194317Sattilio "%s: shared spinning on %p with %u and %u", 798194317Sattilio __func__, lk, spintries, i); 799194317Sattilio if ((lk->lk_lock & 800194317Sattilio LK_EXCLUSIVE_SPINNERS) == 0) 801194317Sattilio break; 802194317Sattilio cpu_spinwait(); 803194317Sattilio } 804196772Sattilio GIANT_RESTORE(); 805194317Sattilio if (i != alk_loops) 806194317Sattilio continue; 807194317Sattilio } 808194317Sattilio#endif 809194317Sattilio 810194317Sattilio /* 811177957Sattilio * Acquire the sleepqueue chain lock because we 812177957Sattilio * probabilly will need to manipulate waiters flags. 813177957Sattilio */ 814177957Sattilio sleepq_lock(&lk->lock_object); 815177957Sattilio x = lk->lk_lock; 816177957Sattilio 817177957Sattilio /* 818177957Sattilio * if the lock has been released while we spun on 819177957Sattilio * the sleepqueue chain lock just try again. 820177957Sattilio */ 821177957Sattilio if (x == LK_UNLOCKED) { 822177957Sattilio sleepq_release(&lk->lock_object); 823177957Sattilio continue; 824134365Skan } 82524269Speter 826194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 82724269Speter /* 828194317Sattilio * The current lock owner might have started executing 829194317Sattilio * on another CPU (or the lock could have changed 830194317Sattilio * owner) while we were waiting on the turnstile 831194317Sattilio * chain lock. If so, drop the turnstile lock and try 832194317Sattilio * again. 833194317Sattilio */ 834194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 835194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 836194317Sattilio owner = (struct thread *)LK_HOLDER(x); 837194317Sattilio if (TD_IS_RUNNING(owner)) { 838194317Sattilio sleepq_release(&lk->lock_object); 839194317Sattilio continue; 840194317Sattilio } 841194317Sattilio } 842194317Sattilio#endif 843194317Sattilio 844194317Sattilio /* 845177957Sattilio * The lock can be in the state where there is a 846177957Sattilio * pending queue of waiters, but still no owner. 847177957Sattilio * This happens when the lock is contested and an 848177957Sattilio * owner is going to claim the lock. 849177957Sattilio * If curthread is the one successfully acquiring it 850177957Sattilio * claim lock ownership and return, preserving waiters 851177957Sattilio * flags. 85224269Speter */ 853194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 854194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 855194317Sattilio v &= ~LK_EXCLUSIVE_SPINNERS; 856177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 857177957Sattilio tid | v)) { 858177957Sattilio sleepq_release(&lk->lock_object); 859177957Sattilio LOCK_LOG2(lk, 860177957Sattilio "%s: %p claimed by a new writer", 861177957Sattilio __func__, lk); 862177957Sattilio break; 863177957Sattilio } 864177957Sattilio sleepq_release(&lk->lock_object); 865177957Sattilio continue; 866177957Sattilio } 867177957Sattilio 868177957Sattilio /* 869177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 870177957Sattilio * fail, loop back and retry. 871177957Sattilio */ 872177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 873177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 874177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 875177957Sattilio sleepq_release(&lk->lock_object); 876177957Sattilio continue; 877177957Sattilio } 878177957Sattilio LOCK_LOG2(lk, "%s: %p set excl waiters flag", 879177957Sattilio __func__, lk); 880177957Sattilio } 881177957Sattilio 882177957Sattilio /* 883177957Sattilio * As far as we have been unable to acquire the 884177957Sattilio * exclusive lock and the exclusive waiters flag 885177957Sattilio * is set, we will sleep. 886177957Sattilio */ 887177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 888177957Sattilio SQ_EXCLUSIVE_QUEUE); 889177957Sattilio flags &= ~LK_INTERLOCK; 890177957Sattilio if (error) { 891177957Sattilio LOCK_LOG3(lk, 892177957Sattilio "%s: interrupted sleep for %p with %d", 893177957Sattilio __func__, lk, error); 89448301Smckusick break; 89548301Smckusick } 896177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 897177957Sattilio __func__, lk); 89824269Speter } 899177957Sattilio if (error == 0) { 900177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 901177957Sattilio contested, waittime, file, line); 902177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 903177957Sattilio lk->lk_recurse, file, line); 904178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 905178159Sattilio LK_TRYWIT(flags), file, line); 906177957Sattilio TD_LOCKS_INC(curthread); 907177957Sattilio STACK_SAVE(lk); 908177957Sattilio } 909177957Sattilio break; 910177957Sattilio case LK_DOWNGRADE: 911177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 912178159Sattilio LOCK_LOG_LOCK("XDOWNGRADE", &lk->lock_object, 0, 0, file, line); 913178159Sattilio WITNESS_DOWNGRADE(&lk->lock_object, 0, file, line); 914178159Sattilio TD_SLOCKS_INC(curthread); 915177957Sattilio 91624269Speter /* 917177957Sattilio * In order to preserve waiters flags, just spin. 91824269Speter */ 919177957Sattilio for (;;) { 920194317Sattilio x = lk->lk_lock; 921194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 922194317Sattilio x &= LK_ALL_WAITERS; 923177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 924178159Sattilio LK_SHARERS_LOCK(1) | x)) 925177957Sattilio break; 926177957Sattilio cpu_spinwait(); 92724269Speter } 92824269Speter break; 929177957Sattilio case LK_RELEASE: 930177957Sattilio _lockmgr_assert(lk, KA_LOCKED, file, line); 931177957Sattilio x = lk->lk_lock; 93224269Speter 933177957Sattilio if ((x & LK_SHARE) == 0) { 934177957Sattilio 935177957Sattilio /* 936177957Sattilio * As first option, treact the lock as if it has not 937177957Sattilio * any waiter. 938177957Sattilio * Fix-up the tid var if the lock has been disowned. 939177957Sattilio */ 940177957Sattilio if (LK_HOLDER(x) == LK_KERNPROC) 941177957Sattilio tid = LK_KERNPROC; 942178159Sattilio else { 943178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, 944178159Sattilio file, line); 945177957Sattilio TD_LOCKS_DEC(curthread); 946178159Sattilio } 947177957Sattilio LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, 948177957Sattilio lk->lk_recurse, file, line); 949177957Sattilio 950177957Sattilio /* 951177957Sattilio * The lock is held in exclusive mode. 952177957Sattilio * If the lock is recursed also, then unrecurse it. 953177957Sattilio */ 954177957Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) { 955177957Sattilio LOCK_LOG2(lk, "%s: %p unrecursing", __func__, 956177957Sattilio lk); 957177957Sattilio lk->lk_recurse--; 958177957Sattilio break; 959176014Sattilio } 960189788Sjeff if (tid != LK_KERNPROC) 961189788Sjeff lock_profile_release_lock(&lk->lock_object); 962177957Sattilio 963177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid, 964177957Sattilio LK_UNLOCKED)) 965177957Sattilio break; 966177957Sattilio 967177957Sattilio sleepq_lock(&lk->lock_object); 968194317Sattilio x = lk->lk_lock; 969177957Sattilio v = LK_UNLOCKED; 970177957Sattilio 971177957Sattilio /* 972177957Sattilio * If the lock has exclusive waiters, give them 973177957Sattilio * preference in order to avoid deadlock with 974177957Sattilio * shared runners up. 975200447Sattilio * If interruptible sleeps left the exclusive queue 976200447Sattilio * empty avoid a starvation for the threads sleeping 977200447Sattilio * on the shared queue by giving them precedence 978200447Sattilio * and cleaning up the exclusive waiters bit anyway. 979201709Sattilio * Please note that lk_exslpfail count may be lying 980201709Sattilio * about the real number of waiters with the 981201709Sattilio * LK_SLEEPFAIL flag on because they may be used in 982201709Sattilio * conjuction with interruptible sleeps so 983201710Sattilio * lk_exslpfail might be considered an 'upper limit' 984201710Sattilio * bound, including the edge cases. 985177957Sattilio */ 986194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 987200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 988200447Sattilio SQ_EXCLUSIVE_QUEUE); 989200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 990200447Sattilio if (lk->lk_exslpfail < realexslp) { 991200447Sattilio lk->lk_exslpfail = 0; 992200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 993200447Sattilio v |= (x & LK_SHARED_WAITERS); 994200447Sattilio } else { 995200447Sattilio lk->lk_exslpfail = 0; 996200447Sattilio LOCK_LOG2(lk, 997200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 998200447Sattilio __func__, lk); 999200447Sattilio LOCK_LOG2(lk, 1000200447Sattilio "%s: %p waking up threads on the exclusive queue", 1001200447Sattilio __func__, lk); 1002200447Sattilio wakeup_swapper = 1003200447Sattilio sleepq_broadcast(&lk->lock_object, 1004200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 1005200447Sattilio queue = SQ_SHARED_QUEUE; 1006200447Sattilio } 1007177957Sattilio } else { 1008201703Sattilio 1009201703Sattilio /* 1010201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL 1011201703Sattilio * on and using interruptible sleeps/timeout 1012201703Sattilio * may have left spourious lk_exslpfail counts 1013201703Sattilio * on, so clean it up anyway. 1014201703Sattilio */ 1015201703Sattilio lk->lk_exslpfail = 0; 1016177957Sattilio queue = SQ_SHARED_QUEUE; 101724269Speter } 1018149723Sssouhlal 1019177957Sattilio LOCK_LOG3(lk, 1020177957Sattilio "%s: %p waking up threads on the %s queue", 1021177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 1022177957Sattilio "exclusive"); 1023177957Sattilio atomic_store_rel_ptr(&lk->lk_lock, v); 1024200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, 1025181334Sjhb SLEEPQ_LK, 0, queue); 1026177957Sattilio sleepq_release(&lk->lock_object); 1027177957Sattilio break; 1028177957Sattilio } else 1029181334Sjhb wakeup_swapper = wakeupshlk(lk, file, line); 103024269Speter break; 1031177957Sattilio case LK_DRAIN: 1032178159Sattilio if (LK_CAN_WITNESS(flags)) 1033178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 1034182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 103524269Speter 103624269Speter /* 1037180798Skib * Trying to drain a lock we already own will result in a 1038177957Sattilio * deadlock. 103924269Speter */ 1040177957Sattilio if (lockmgr_xlocked(lk)) { 1041177957Sattilio if (flags & LK_INTERLOCK) 1042177957Sattilio class->lc_unlock(ilk); 1043177957Sattilio panic("%s: draining %s with the lock held @ %s:%d\n", 1044177957Sattilio __func__, iwmesg, file, line); 1045177957Sattilio } 104628345Sdyson 1047177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) { 1048177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 1049177957Sattilio &contested, &waittime); 105024269Speter 1051177957Sattilio /* 1052177957Sattilio * If the lock is expected to not sleep just give up 1053177957Sattilio * and return. 1054177957Sattilio */ 1055177957Sattilio if (LK_TRYOP(flags)) { 1056177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 1057177957Sattilio __func__, lk); 1058177957Sattilio error = EBUSY; 1059177957Sattilio break; 1060177957Sattilio } 106124269Speter 1062177957Sattilio /* 1063177957Sattilio * Acquire the sleepqueue chain lock because we 1064177957Sattilio * probabilly will need to manipulate waiters flags. 1065177957Sattilio */ 1066177957Sattilio sleepq_lock(&lk->lock_object); 1067177957Sattilio x = lk->lk_lock; 106829653Sdyson 1069177957Sattilio /* 1070177957Sattilio * if the lock has been released while we spun on 1071177957Sattilio * the sleepqueue chain lock just try again. 1072177957Sattilio */ 1073177957Sattilio if (x == LK_UNLOCKED) { 1074177957Sattilio sleepq_release(&lk->lock_object); 1075177957Sattilio continue; 1076177957Sattilio } 1077176320Sattilio 1078194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 1079194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 1080194317Sattilio v = (x & ~LK_EXCLUSIVE_SPINNERS); 1081200447Sattilio 1082200447Sattilio /* 1083200447Sattilio * If interruptible sleeps left the exclusive 1084200447Sattilio * queue empty avoid a starvation for the 1085200447Sattilio * threads sleeping on the shared queue by 1086200447Sattilio * giving them precedence and cleaning up the 1087200447Sattilio * exclusive waiters bit anyway. 1088201709Sattilio * Please note that lk_exslpfail count may be 1089201709Sattilio * lying about the real number of waiters with 1090201709Sattilio * the LK_SLEEPFAIL flag on because they may 1091201709Sattilio * be used in conjuction with interruptible 1092201710Sattilio * sleeps so lk_exslpfail might be considered 1093201710Sattilio * an 'upper limit' bound, including the edge 1094201709Sattilio * cases. 1095200447Sattilio */ 1096177957Sattilio if (v & LK_EXCLUSIVE_WAITERS) { 1097177957Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1098177957Sattilio v &= ~LK_EXCLUSIVE_WAITERS; 1099177957Sattilio } else { 1100201703Sattilio 1101201703Sattilio /* 1102201703Sattilio * Exclusive waiters sleeping with 1103201703Sattilio * LK_SLEEPFAIL on and using 1104201703Sattilio * interruptible sleeps/timeout may 1105201703Sattilio * have left spourious lk_exslpfail 1106201703Sattilio * counts on, so clean it up anyway. 1107201703Sattilio */ 1108177957Sattilio MPASS(v & LK_SHARED_WAITERS); 1109201703Sattilio lk->lk_exslpfail = 0; 1110177957Sattilio queue = SQ_SHARED_QUEUE; 1111177957Sattilio v &= ~LK_SHARED_WAITERS; 1112177957Sattilio } 1113200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE) { 1114200447Sattilio realexslp = 1115200447Sattilio sleepq_sleepcnt(&lk->lock_object, 1116200447Sattilio SQ_EXCLUSIVE_QUEUE); 1117200447Sattilio if (lk->lk_exslpfail >= realexslp) { 1118200447Sattilio lk->lk_exslpfail = 0; 1119200447Sattilio queue = SQ_SHARED_QUEUE; 1120200447Sattilio v &= ~LK_SHARED_WAITERS; 1121200447Sattilio if (realexslp != 0) { 1122200447Sattilio LOCK_LOG2(lk, 1123200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1124200447Sattilio __func__, lk); 1125200447Sattilio LOCK_LOG2(lk, 1126200447Sattilio "%s: %p waking up threads on the exclusive queue", 1127200447Sattilio __func__, lk); 1128200447Sattilio wakeup_swapper = 1129200447Sattilio sleepq_broadcast( 1130200447Sattilio &lk->lock_object, 1131200447Sattilio SLEEPQ_LK, 0, 1132200447Sattilio SQ_EXCLUSIVE_QUEUE); 1133200447Sattilio } 1134200447Sattilio } else 1135200447Sattilio lk->lk_exslpfail = 0; 1136200447Sattilio } 1137177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, v)) { 1138177957Sattilio sleepq_release(&lk->lock_object); 1139177957Sattilio continue; 1140177957Sattilio } 1141177957Sattilio LOCK_LOG3(lk, 1142177957Sattilio "%s: %p waking up all threads on the %s queue", 1143177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? 1144177957Sattilio "shared" : "exclusive"); 1145182010Sjhb wakeup_swapper |= sleepq_broadcast( 1146181334Sjhb &lk->lock_object, SLEEPQ_LK, 0, queue); 1147177957Sattilio 1148177957Sattilio /* 1149177957Sattilio * If shared waiters have been woken up we need 1150177957Sattilio * to wait for one of them to acquire the lock 1151177957Sattilio * before to set the exclusive waiters in 1152177957Sattilio * order to avoid a deadlock. 1153177957Sattilio */ 1154177957Sattilio if (queue == SQ_SHARED_QUEUE) { 1155177957Sattilio for (v = lk->lk_lock; 1156177957Sattilio (v & LK_SHARE) && !LK_SHARERS(v); 1157177957Sattilio v = lk->lk_lock) 1158177957Sattilio cpu_spinwait(); 1159177957Sattilio } 1160177957Sattilio } 1161177957Sattilio 1162177957Sattilio /* 1163177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 1164177957Sattilio * fail, loop back and retry. 1165177957Sattilio */ 1166177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 1167177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 1168177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 1169177957Sattilio sleepq_release(&lk->lock_object); 1170177957Sattilio continue; 1171177957Sattilio } 1172177957Sattilio LOCK_LOG2(lk, "%s: %p set drain waiters flag", 1173177957Sattilio __func__, lk); 1174177957Sattilio } 1175177957Sattilio 1176177957Sattilio /* 1177177957Sattilio * As far as we have been unable to acquire the 1178177957Sattilio * exclusive lock and the exclusive waiters flag 1179177957Sattilio * is set, we will sleep. 1180177957Sattilio */ 1181177957Sattilio if (flags & LK_INTERLOCK) { 1182177957Sattilio class->lc_unlock(ilk); 1183177957Sattilio flags &= ~LK_INTERLOCK; 1184177957Sattilio } 1185178159Sattilio GIANT_SAVE(); 1186177957Sattilio sleepq_add(&lk->lock_object, NULL, iwmesg, SLEEPQ_LK, 1187177957Sattilio SQ_EXCLUSIVE_QUEUE); 1188177957Sattilio sleepq_wait(&lk->lock_object, ipri & PRIMASK); 1189178159Sattilio GIANT_RESTORE(); 1190177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 1191177957Sattilio __func__, lk); 119229653Sdyson } 1193177957Sattilio 1194177957Sattilio if (error == 0) { 1195177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 1196177957Sattilio contested, waittime, file, line); 1197177957Sattilio LOCK_LOG_LOCK("DRAIN", &lk->lock_object, 0, 1198177957Sattilio lk->lk_recurse, file, line); 1199178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 1200178159Sattilio LK_TRYWIT(flags), file, line); 1201177957Sattilio TD_LOCKS_INC(curthread); 1202177957Sattilio STACK_SAVE(lk); 1203177957Sattilio } 1204177957Sattilio break; 1205177957Sattilio default: 1206177957Sattilio if (flags & LK_INTERLOCK) 1207177957Sattilio class->lc_unlock(ilk); 1208177957Sattilio panic("%s: unknown lockmgr request 0x%x\n", __func__, op); 120929653Sdyson } 1210177957Sattilio 1211177957Sattilio if (flags & LK_INTERLOCK) 1212177957Sattilio class->lc_unlock(ilk); 1213181334Sjhb if (wakeup_swapper) 1214181334Sjhb kick_proc0(); 1215177957Sattilio 1216177957Sattilio return (error); 121729653Sdyson} 121829653Sdyson 121929653Sdysonvoid 1220177957Sattilio_lockmgr_disown(struct lock *lk, const char *file, int line) 122129653Sdyson{ 1222177957Sattilio uintptr_t tid, x; 1223176014Sattilio 1224177957Sattilio tid = (uintptr_t)curthread; 1225177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 122629653Sdyson 1227177957Sattilio /* 1228180798Skib * If the owner is already LK_KERNPROC just skip the whole operation. 1229177957Sattilio */ 1230177957Sattilio if (LK_HOLDER(lk->lk_lock) != tid) 1231177957Sattilio return; 1232189788Sjeff lock_profile_release_lock(&lk->lock_object); 1233178159Sattilio LOCK_LOG_LOCK("XDISOWN", &lk->lock_object, 0, 0, file, line); 1234178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); 1235178159Sattilio TD_LOCKS_DEC(curthread); 1236199008Sattilio STACK_SAVE(lk); 123729653Sdyson 1238177957Sattilio /* 1239177957Sattilio * In order to preserve waiters flags, just spin. 1240177957Sattilio */ 1241177957Sattilio for (;;) { 1242194317Sattilio x = lk->lk_lock; 1243194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1244194317Sattilio x &= LK_ALL_WAITERS; 1245178166Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 1246178159Sattilio LK_KERNPROC | x)) 1247177957Sattilio return; 1248177957Sattilio cpu_spinwait(); 1249177957Sattilio } 125066615Sjasone} 125166615Sjasone 1252175166Sattiliovoid 1253177957Sattiliolockmgr_printinfo(struct lock *lk) 1254175166Sattilio{ 1255175166Sattilio struct thread *td; 1256177957Sattilio uintptr_t x; 1257175166Sattilio 1258177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1259188244Sjhb printf("lock type %s: UNLOCKED\n", lk->lock_object.lo_name); 1260177957Sattilio else if (lk->lk_lock & LK_SHARE) 1261188244Sjhb printf("lock type %s: SHARED (count %ju)\n", 1262177957Sattilio lk->lock_object.lo_name, 1263177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1264177957Sattilio else { 1265177957Sattilio td = lockmgr_xholder(lk); 1266188244Sjhb printf("lock type %s: EXCL by thread %p (pid %d)\n", 1267177957Sattilio lk->lock_object.lo_name, td, td->td_proc->p_pid); 1268177957Sattilio } 1269175166Sattilio 1270177957Sattilio x = lk->lk_lock; 1271177957Sattilio if (x & LK_EXCLUSIVE_WAITERS) 1272177957Sattilio printf(" with exclusive waiters pending\n"); 1273177957Sattilio if (x & LK_SHARED_WAITERS) 1274177957Sattilio printf(" with shared waiters pending\n"); 1275194317Sattilio if (x & LK_EXCLUSIVE_SPINNERS) 1276194317Sattilio printf(" with exclusive spinners pending\n"); 1277177957Sattilio 1278177957Sattilio STACK_PRINT(lk); 1279175166Sattilio} 1280175166Sattilio 128129653Sdysonint 1282177957Sattiliolockstatus(struct lock *lk) 128329653Sdyson{ 1284177957Sattilio uintptr_t v, x; 1285177957Sattilio int ret; 128629653Sdyson 1287177957Sattilio ret = LK_SHARED; 1288177957Sattilio x = lk->lk_lock; 1289177957Sattilio v = LK_HOLDER(x); 1290175635Sattilio 1291177957Sattilio if ((x & LK_SHARE) == 0) { 1292177957Sattilio if (v == (uintptr_t)curthread || v == LK_KERNPROC) 1293177957Sattilio ret = LK_EXCLUSIVE; 129454444Seivind else 1295177957Sattilio ret = LK_EXCLOTHER; 1296177957Sattilio } else if (x == LK_UNLOCKED) 1297177957Sattilio ret = 0; 129829653Sdyson 1299177957Sattilio return (ret); 130024269Speter} 1301161322Sjhb 1302176249Sattilio#ifdef INVARIANT_SUPPORT 1303176249Sattilio#ifndef INVARIANTS 1304177957Sattilio#undef _lockmgr_assert 1305176249Sattilio#endif 1306176249Sattilio 1307176249Sattiliovoid 1308177957Sattilio_lockmgr_assert(struct lock *lk, int what, const char *file, int line) 1309176249Sattilio{ 1310176249Sattilio int slocked = 0; 1311176249Sattilio 1312176249Sattilio if (panicstr != NULL) 1313176249Sattilio return; 1314176249Sattilio switch (what) { 1315176249Sattilio case KA_SLOCKED: 1316176249Sattilio case KA_SLOCKED | KA_NOTRECURSED: 1317176249Sattilio case KA_SLOCKED | KA_RECURSED: 1318176249Sattilio slocked = 1; 1319176249Sattilio case KA_LOCKED: 1320176249Sattilio case KA_LOCKED | KA_NOTRECURSED: 1321176249Sattilio case KA_LOCKED | KA_RECURSED: 1322178159Sattilio#ifdef WITNESS 1323178159Sattilio 1324178159Sattilio /* 1325178159Sattilio * We cannot trust WITNESS if the lock is held in exclusive 1326178159Sattilio * mode and a call to lockmgr_disown() happened. 1327178159Sattilio * Workaround this skipping the check if the lock is held in 1328178159Sattilio * exclusive mode even for the KA_LOCKED case. 1329178159Sattilio */ 1330178159Sattilio if (slocked || (lk->lk_lock & LK_SHARE)) { 1331178159Sattilio witness_assert(&lk->lock_object, what, file, line); 1332178159Sattilio break; 1333178159Sattilio } 1334178159Sattilio#endif 1335177957Sattilio if (lk->lk_lock == LK_UNLOCKED || 1336177957Sattilio ((lk->lk_lock & LK_SHARE) == 0 && (slocked || 1337177957Sattilio (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk))))) 1338176249Sattilio panic("Lock %s not %slocked @ %s:%d\n", 1339177957Sattilio lk->lock_object.lo_name, slocked ? "share" : "", 1340176249Sattilio file, line); 1341177957Sattilio 1342177957Sattilio if ((lk->lk_lock & LK_SHARE) == 0) { 1343177957Sattilio if (lockmgr_recursed(lk)) { 1344176249Sattilio if (what & KA_NOTRECURSED) 1345176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1346177957Sattilio lk->lock_object.lo_name, file, 1347177957Sattilio line); 1348176249Sattilio } else if (what & KA_RECURSED) 1349176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1350177957Sattilio lk->lock_object.lo_name, file, line); 1351176249Sattilio } 1352176249Sattilio break; 1353176249Sattilio case KA_XLOCKED: 1354176249Sattilio case KA_XLOCKED | KA_NOTRECURSED: 1355176249Sattilio case KA_XLOCKED | KA_RECURSED: 1356177957Sattilio if (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk)) 1357176249Sattilio panic("Lock %s not exclusively locked @ %s:%d\n", 1358177957Sattilio lk->lock_object.lo_name, file, line); 1359177957Sattilio if (lockmgr_recursed(lk)) { 1360176249Sattilio if (what & KA_NOTRECURSED) 1361176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1362177957Sattilio lk->lock_object.lo_name, file, line); 1363176249Sattilio } else if (what & KA_RECURSED) 1364176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1365177957Sattilio lk->lock_object.lo_name, file, line); 1366176249Sattilio break; 1367176249Sattilio case KA_UNLOCKED: 1368177957Sattilio if (lockmgr_xlocked(lk) || lockmgr_disowned(lk)) 1369176249Sattilio panic("Lock %s exclusively locked @ %s:%d\n", 1370177957Sattilio lk->lock_object.lo_name, file, line); 1371176249Sattilio break; 1372176249Sattilio default: 1373177957Sattilio panic("Unknown lockmgr assertion: %d @ %s:%d\n", what, file, 1374177957Sattilio line); 1375176249Sattilio } 1376176249Sattilio} 1377177957Sattilio#endif 1378176249Sattilio 1379161322Sjhb#ifdef DDB 1380161337Sjhbint 1381161337Sjhblockmgr_chain(struct thread *td, struct thread **ownerp) 1382161337Sjhb{ 1383177957Sattilio struct lock *lk; 1384161337Sjhb 1385177957Sattilio lk = td->td_wchan; 1386161337Sjhb 1387177957Sattilio if (LOCK_CLASS(&lk->lock_object) != &lock_class_lockmgr) 1388177957Sattilio return (0); 1389177957Sattilio db_printf("blocked on lockmgr %s", lk->lock_object.lo_name); 1390177957Sattilio if (lk->lk_lock & LK_SHARE) 1391177957Sattilio db_printf("SHARED (count %ju)\n", 1392177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1393177957Sattilio else 1394177957Sattilio db_printf("EXCL\n"); 1395177957Sattilio *ownerp = lockmgr_xholder(lk); 1396161337Sjhb 1397161337Sjhb return (1); 1398161337Sjhb} 1399161337Sjhb 1400177957Sattiliostatic void 1401164246Skmacydb_show_lockmgr(struct lock_object *lock) 1402161322Sjhb{ 1403161322Sjhb struct thread *td; 1404177957Sattilio struct lock *lk; 1405161322Sjhb 1406177957Sattilio lk = (struct lock *)lock; 1407161322Sjhb 1408168070Sjhb db_printf(" state: "); 1409177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1410161322Sjhb db_printf("UNLOCKED\n"); 1411177957Sattilio else if (lk->lk_lock & LK_SHARE) 1412177957Sattilio db_printf("SLOCK: %ju\n", (uintmax_t)LK_SHARERS(lk->lk_lock)); 1413177957Sattilio else { 1414177957Sattilio td = lockmgr_xholder(lk); 1415177957Sattilio if (td == (struct thread *)LK_KERNPROC) 1416177957Sattilio db_printf("XLOCK: LK_KERNPROC\n"); 1417177957Sattilio else 1418177957Sattilio db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td, 1419177957Sattilio td->td_tid, td->td_proc->p_pid, 1420177957Sattilio td->td_proc->p_comm); 1421177957Sattilio if (lockmgr_recursed(lk)) 1422177957Sattilio db_printf(" recursed: %d\n", lk->lk_recurse); 1423177957Sattilio } 1424177957Sattilio db_printf(" waiters: "); 1425177957Sattilio switch (lk->lk_lock & LK_ALL_WAITERS) { 1426177957Sattilio case LK_SHARED_WAITERS: 1427177957Sattilio db_printf("shared\n"); 1428192022Strasz break; 1429177957Sattilio case LK_EXCLUSIVE_WAITERS: 1430177957Sattilio db_printf("exclusive\n"); 1431177957Sattilio break; 1432177957Sattilio case LK_ALL_WAITERS: 1433177957Sattilio db_printf("shared and exclusive\n"); 1434177957Sattilio break; 1435177957Sattilio default: 1436177957Sattilio db_printf("none\n"); 1437177957Sattilio } 1438194317Sattilio db_printf(" spinners: "); 1439194317Sattilio if (lk->lk_lock & LK_EXCLUSIVE_SPINNERS) 1440194317Sattilio db_printf("exclusive\n"); 1441194317Sattilio else 1442194317Sattilio db_printf("none\n"); 1443161322Sjhb} 1444161322Sjhb#endif 1445