kern_lock.c revision 243900
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" 31233628Sfabient#include "opt_hwpmc_hooks.h" 32192853Ssson#include "opt_kdtrace.h" 33177957Sattilio 34116182Sobrien#include <sys/cdefs.h> 35116182Sobrien__FBSDID("$FreeBSD: head/sys/kern/kern_lock.c 243900 2012-12-05 15:11:01Z attilio $"); 36116182Sobrien 3724269Speter#include <sys/param.h> 3884812Sjhb#include <sys/ktr.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 57233628Sfabient#ifdef HWPMC_HOOKS 58233628Sfabient#include <sys/pmckern.h> 59233628SfabientPMC_SOFT_DECLARE( , , lock, failed); 60233628Sfabient#endif 61233628Sfabient 62194317SattilioCTASSERT(((LK_ADAPTIVE | LK_NOSHARE) & LO_CLASSFLAGS) == 63194317Sattilio (LK_ADAPTIVE | LK_NOSHARE)); 64194317SattilioCTASSERT(LK_UNLOCKED == (LK_UNLOCKED & 65194317Sattilio ~(LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS))); 66177957Sattilio 67177957Sattilio#define SQ_EXCLUSIVE_QUEUE 0 68177957Sattilio#define SQ_SHARED_QUEUE 1 69177957Sattilio 70177957Sattilio#ifndef INVARIANTS 71177957Sattilio#define _lockmgr_assert(lk, what, file, line) 72177957Sattilio#define TD_LOCKS_INC(td) 73177957Sattilio#define TD_LOCKS_DEC(td) 74177957Sattilio#else 75177957Sattilio#define TD_LOCKS_INC(td) ((td)->td_locks++) 76177957Sattilio#define TD_LOCKS_DEC(td) ((td)->td_locks--) 77177957Sattilio#endif 78177957Sattilio#define TD_SLOCKS_INC(td) ((td)->td_lk_slocks++) 79177957Sattilio#define TD_SLOCKS_DEC(td) ((td)->td_lk_slocks--) 80177957Sattilio 81177957Sattilio#ifndef DEBUG_LOCKS 82177957Sattilio#define STACK_PRINT(lk) 83177957Sattilio#define STACK_SAVE(lk) 84177957Sattilio#define STACK_ZERO(lk) 85177957Sattilio#else 86177957Sattilio#define STACK_PRINT(lk) stack_print_ddb(&(lk)->lk_stack) 87177957Sattilio#define STACK_SAVE(lk) stack_save(&(lk)->lk_stack) 88177957Sattilio#define STACK_ZERO(lk) stack_zero(&(lk)->lk_stack) 89177957Sattilio#endif 90177957Sattilio 91177957Sattilio#define LOCK_LOG2(lk, string, arg1, arg2) \ 92177957Sattilio if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \ 93177957Sattilio CTR2(KTR_LOCK, (string), (arg1), (arg2)) 94177957Sattilio#define LOCK_LOG3(lk, string, arg1, arg2, arg3) \ 95177957Sattilio if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \ 96177957Sattilio CTR3(KTR_LOCK, (string), (arg1), (arg2), (arg3)) 97177957Sattilio 98178159Sattilio#define GIANT_DECLARE \ 99178159Sattilio int _i = 0; \ 100178159Sattilio WITNESS_SAVE_DECL(Giant) 101178159Sattilio#define GIANT_RESTORE() do { \ 102178159Sattilio if (_i > 0) { \ 103178159Sattilio while (_i--) \ 104178159Sattilio mtx_lock(&Giant); \ 105178159Sattilio WITNESS_RESTORE(&Giant.lock_object, Giant); \ 106178159Sattilio } \ 107178159Sattilio} while (0) 108178159Sattilio#define GIANT_SAVE() do { \ 109178159Sattilio if (mtx_owned(&Giant)) { \ 110178159Sattilio WITNESS_SAVE(&Giant.lock_object, Giant); \ 111178159Sattilio while (mtx_owned(&Giant)) { \ 112178159Sattilio _i++; \ 113178159Sattilio mtx_unlock(&Giant); \ 114178159Sattilio } \ 115178159Sattilio } \ 116178159Sattilio} while (0) 117178159Sattilio 118177957Sattilio#define LK_CAN_SHARE(x) \ 119177957Sattilio (((x) & LK_SHARE) && (((x) & LK_EXCLUSIVE_WAITERS) == 0 || \ 120194317Sattilio ((x) & LK_EXCLUSIVE_SPINNERS) == 0 || \ 121177982Sattilio curthread->td_lk_slocks || (curthread->td_pflags & TDP_DEADLKTREAT))) 122178159Sattilio#define LK_TRYOP(x) \ 123178159Sattilio ((x) & LK_NOWAIT) 124177957Sattilio 125178159Sattilio#define LK_CAN_WITNESS(x) \ 126178159Sattilio (((x) & LK_NOWITNESS) == 0 && !LK_TRYOP(x)) 127178159Sattilio#define LK_TRYWIT(x) \ 128178159Sattilio (LK_TRYOP(x) ? LOP_TRYLOCK : 0) 129178159Sattilio 130194317Sattilio#define LK_CAN_ADAPT(lk, f) \ 131194317Sattilio (((lk)->lock_object.lo_flags & LK_ADAPTIVE) != 0 && \ 132194317Sattilio ((f) & LK_SLEEPFAIL) == 0) 133194317Sattilio 134177957Sattilio#define lockmgr_disowned(lk) \ 135177957Sattilio (((lk)->lk_lock & ~(LK_FLAGMASK & ~LK_SHARE)) == LK_KERNPROC) 136177957Sattilio 137177957Sattilio#define lockmgr_xlocked(lk) \ 138177957Sattilio (((lk)->lk_lock & ~(LK_FLAGMASK & ~LK_SHARE)) == (uintptr_t)curthread) 139177957Sattilio 140227588Spjdstatic void assert_lockmgr(const struct lock_object *lock, int how); 141177957Sattilio#ifdef DDB 142227588Spjdstatic void db_show_lockmgr(const struct lock_object *lock); 143177957Sattilio#endif 144227588Spjdstatic void lock_lockmgr(struct lock_object *lock, int how); 145192853Ssson#ifdef KDTRACE_HOOKS 146227588Spjdstatic int owner_lockmgr(const struct lock_object *lock, 147227588Spjd struct thread **owner); 148192853Ssson#endif 149227588Spjdstatic int unlock_lockmgr(struct lock_object *lock); 150177957Sattilio 151164246Skmacystruct lock_class lock_class_lockmgr = { 152167366Sjhb .lc_name = "lockmgr", 153177957Sattilio .lc_flags = LC_RECURSABLE | LC_SLEEPABLE | LC_SLEEPLOCK | LC_UPGRADABLE, 154173733Sattilio .lc_assert = assert_lockmgr, 155164246Skmacy#ifdef DDB 156167368Sjhb .lc_ddb_show = db_show_lockmgr, 157164246Skmacy#endif 158167368Sjhb .lc_lock = lock_lockmgr, 159192853Ssson .lc_unlock = unlock_lockmgr, 160192853Ssson#ifdef KDTRACE_HOOKS 161192853Ssson .lc_owner = owner_lockmgr, 162192853Ssson#endif 163164246Skmacy}; 164164246Skmacy 165194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 166194317Sattiliostatic u_int alk_retries = 10; 167194317Sattiliostatic u_int alk_loops = 10000; 168227309Sedstatic SYSCTL_NODE(_debug, OID_AUTO, lockmgr, CTLFLAG_RD, NULL, 169227309Sed "lockmgr debugging"); 170194317SattilioSYSCTL_UINT(_debug_lockmgr, OID_AUTO, retries, CTLFLAG_RW, &alk_retries, 0, ""); 171194317SattilioSYSCTL_UINT(_debug_lockmgr, OID_AUTO, loops, CTLFLAG_RW, &alk_loops, 0, ""); 172194317Sattilio#endif 173194317Sattilio 174177957Sattiliostatic __inline struct thread * 175227588Spjdlockmgr_xholder(const struct lock *lk) 176177957Sattilio{ 177177957Sattilio uintptr_t x; 178176249Sattilio 179177957Sattilio x = lk->lk_lock; 180177957Sattilio return ((x & LK_SHARE) ? NULL : (struct thread *)LK_HOLDER(x)); 181177957Sattilio} 182177957Sattilio 18324269Speter/* 184177957Sattilio * It assumes sleepq_lock held and returns with this one unheld. 185177957Sattilio * It also assumes the generic interlock is sane and previously checked. 186177957Sattilio * If LK_INTERLOCK is specified the interlock is not reacquired after the 187177957Sattilio * sleep. 18824269Speter */ 189177957Sattiliostatic __inline int 190177957Sattiliosleeplk(struct lock *lk, u_int flags, struct lock_object *ilk, 191177957Sattilio const char *wmesg, int pri, int timo, int queue) 192177957Sattilio{ 193178159Sattilio GIANT_DECLARE; 194177957Sattilio struct lock_class *class; 195177957Sattilio int catch, error; 19624269Speter 197177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 198179306Sattilio catch = pri & PCATCH; 199177957Sattilio pri &= PRIMASK; 200177957Sattilio error = 0; 201177957Sattilio 202177957Sattilio LOCK_LOG3(lk, "%s: %p blocking on the %s sleepqueue", __func__, lk, 203177957Sattilio (queue == SQ_EXCLUSIVE_QUEUE) ? "exclusive" : "shared"); 204177957Sattilio 205177957Sattilio if (flags & LK_INTERLOCK) 206177957Sattilio class->lc_unlock(ilk); 207200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE && (flags & LK_SLEEPFAIL) != 0) 208200447Sattilio lk->lk_exslpfail++; 209178159Sattilio GIANT_SAVE(); 210177957Sattilio sleepq_add(&lk->lock_object, NULL, wmesg, SLEEPQ_LK | (catch ? 211177957Sattilio SLEEPQ_INTERRUPTIBLE : 0), queue); 212177957Sattilio if ((flags & LK_TIMELOCK) && timo) 213177957Sattilio sleepq_set_timeout(&lk->lock_object, timo); 214177957Sattilio 215177957Sattilio /* 216177957Sattilio * Decisional switch for real sleeping. 217177957Sattilio */ 218177957Sattilio if ((flags & LK_TIMELOCK) && timo && catch) 219177957Sattilio error = sleepq_timedwait_sig(&lk->lock_object, pri); 220177957Sattilio else if ((flags & LK_TIMELOCK) && timo) 221177957Sattilio error = sleepq_timedwait(&lk->lock_object, pri); 222177957Sattilio else if (catch) 223177957Sattilio error = sleepq_wait_sig(&lk->lock_object, pri); 224177957Sattilio else 225177957Sattilio sleepq_wait(&lk->lock_object, pri); 226178159Sattilio GIANT_RESTORE(); 227177957Sattilio if ((flags & LK_SLEEPFAIL) && error == 0) 228177957Sattilio error = ENOLCK; 229177957Sattilio 230177957Sattilio return (error); 231177957Sattilio} 232177957Sattilio 233181334Sjhbstatic __inline int 234177957Sattiliowakeupshlk(struct lock *lk, const char *file, int line) 235177957Sattilio{ 236177957Sattilio uintptr_t v, x; 237200447Sattilio u_int realexslp; 238181334Sjhb int queue, wakeup_swapper; 239177957Sattilio 240177957Sattilio TD_LOCKS_DEC(curthread); 241177957Sattilio TD_SLOCKS_DEC(curthread); 242178159Sattilio WITNESS_UNLOCK(&lk->lock_object, 0, file, line); 243177957Sattilio LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, file, line); 244177957Sattilio 245181334Sjhb wakeup_swapper = 0; 246177957Sattilio for (;;) { 247177957Sattilio x = lk->lk_lock; 248177957Sattilio 249177957Sattilio /* 250177957Sattilio * If there is more than one shared lock held, just drop one 251177957Sattilio * and return. 252177957Sattilio */ 253177957Sattilio if (LK_SHARERS(x) > 1) { 254197735Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, x, 255177957Sattilio x - LK_ONE_SHARER)) 256177957Sattilio break; 257177957Sattilio continue; 258177957Sattilio } 259177957Sattilio 260177957Sattilio /* 261177957Sattilio * If there are not waiters on the exclusive queue, drop the 262177957Sattilio * lock quickly. 263177957Sattilio */ 264177957Sattilio if ((x & LK_ALL_WAITERS) == 0) { 265194317Sattilio MPASS((x & ~LK_EXCLUSIVE_SPINNERS) == 266194317Sattilio LK_SHARERS_LOCK(1)); 267197735Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, x, LK_UNLOCKED)) 268177957Sattilio break; 269177957Sattilio continue; 270177957Sattilio } 271177957Sattilio 272177957Sattilio /* 273177957Sattilio * We should have a sharer with waiters, so enter the hard 274177957Sattilio * path in order to handle wakeups correctly. 275177957Sattilio */ 276177957Sattilio sleepq_lock(&lk->lock_object); 277194317Sattilio x = lk->lk_lock & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 278177957Sattilio v = LK_UNLOCKED; 279177957Sattilio 280177957Sattilio /* 281177957Sattilio * If the lock has exclusive waiters, give them preference in 282177957Sattilio * order to avoid deadlock with shared runners up. 283200447Sattilio * If interruptible sleeps left the exclusive queue empty 284200447Sattilio * avoid a starvation for the threads sleeping on the shared 285200447Sattilio * queue by giving them precedence and cleaning up the 286200447Sattilio * exclusive waiters bit anyway. 287201709Sattilio * Please note that lk_exslpfail count may be lying about 288201709Sattilio * the real number of waiters with the LK_SLEEPFAIL flag on 289201709Sattilio * because they may be used in conjuction with interruptible 290201710Sattilio * sleeps so lk_exslpfail might be considered an 'upper limit' 291201710Sattilio * bound, including the edge cases. 292177957Sattilio */ 293200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 294200447Sattilio SQ_EXCLUSIVE_QUEUE); 295200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 296200447Sattilio if (lk->lk_exslpfail < realexslp) { 297200447Sattilio lk->lk_exslpfail = 0; 298200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 299200447Sattilio v |= (x & LK_SHARED_WAITERS); 300200447Sattilio } else { 301200447Sattilio lk->lk_exslpfail = 0; 302200447Sattilio LOCK_LOG2(lk, 303200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 304200447Sattilio __func__, lk); 305200447Sattilio LOCK_LOG2(lk, 306200447Sattilio "%s: %p waking up threads on the exclusive queue", 307200447Sattilio __func__, lk); 308200447Sattilio wakeup_swapper = 309200447Sattilio sleepq_broadcast(&lk->lock_object, 310200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 311200447Sattilio queue = SQ_SHARED_QUEUE; 312200447Sattilio } 313200447Sattilio 314177957Sattilio } else { 315201703Sattilio 316201703Sattilio /* 317201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL on 318201703Sattilio * and using interruptible sleeps/timeout may have 319201703Sattilio * left spourious lk_exslpfail counts on, so clean 320201703Sattilio * it up anyway. 321201703Sattilio */ 322201703Sattilio lk->lk_exslpfail = 0; 323177957Sattilio queue = SQ_SHARED_QUEUE; 324177957Sattilio } 325177957Sattilio 326197735Sattilio if (!atomic_cmpset_rel_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x, 327177957Sattilio v)) { 328177957Sattilio sleepq_release(&lk->lock_object); 329177957Sattilio continue; 330177957Sattilio } 331177957Sattilio LOCK_LOG3(lk, "%s: %p waking up threads on the %s queue", 332177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 333177957Sattilio "exclusive"); 334200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, SLEEPQ_LK, 335181334Sjhb 0, queue); 336177957Sattilio sleepq_release(&lk->lock_object); 337177957Sattilio break; 338177957Sattilio } 339177957Sattilio 340177957Sattilio lock_profile_release_lock(&lk->lock_object); 341181334Sjhb return (wakeup_swapper); 342177957Sattilio} 343177957Sattilio 344177957Sattiliostatic void 345227588Spjdassert_lockmgr(const struct lock_object *lock, int what) 346173733Sattilio{ 347173733Sattilio 348173733Sattilio panic("lockmgr locks do not support assertions"); 349173733Sattilio} 350173733Sattilio 351177957Sattiliostatic void 352167368Sjhblock_lockmgr(struct lock_object *lock, int how) 353167368Sjhb{ 354167368Sjhb 355167368Sjhb panic("lockmgr locks do not support sleep interlocking"); 356167368Sjhb} 357167368Sjhb 358177957Sattiliostatic int 359167368Sjhbunlock_lockmgr(struct lock_object *lock) 360167368Sjhb{ 361167368Sjhb 362167368Sjhb panic("lockmgr locks do not support sleep interlocking"); 363167368Sjhb} 364167368Sjhb 365192853Ssson#ifdef KDTRACE_HOOKS 366192853Sssonstatic int 367227588Spjdowner_lockmgr(const struct lock_object *lock, struct thread **owner) 368192853Ssson{ 369192853Ssson 370192853Ssson panic("lockmgr locks do not support owner inquiring"); 371192853Ssson} 372192853Ssson#endif 373192853Ssson 374177957Sattiliovoid 375177957Sattiliolockinit(struct lock *lk, int pri, const char *wmesg, int timo, int flags) 376177957Sattilio{ 377177957Sattilio int iflags; 37829653Sdyson 379177957Sattilio MPASS((flags & ~LK_INIT_MASK) == 0); 380196334Sattilio ASSERT_ATOMIC_LOAD_PTR(lk->lk_lock, 381196334Sattilio ("%s: lockmgr not aligned for %s: %p", __func__, wmesg, 382196334Sattilio &lk->lk_lock)); 38324269Speter 384193307Sattilio iflags = LO_SLEEPABLE | LO_UPGRADABLE; 385193307Sattilio if (flags & LK_CANRECURSE) 386193307Sattilio iflags |= LO_RECURSABLE; 387177957Sattilio if ((flags & LK_NODUP) == 0) 388177957Sattilio iflags |= LO_DUPOK; 389177957Sattilio if (flags & LK_NOPROFILE) 390177957Sattilio iflags |= LO_NOPROFILE; 391177957Sattilio if ((flags & LK_NOWITNESS) == 0) 392177957Sattilio iflags |= LO_WITNESS; 393177957Sattilio if (flags & LK_QUIET) 394177957Sattilio iflags |= LO_QUIET; 395194317Sattilio iflags |= flags & (LK_ADAPTIVE | LK_NOSHARE); 396177957Sattilio 397177957Sattilio lk->lk_lock = LK_UNLOCKED; 398177957Sattilio lk->lk_recurse = 0; 399200447Sattilio lk->lk_exslpfail = 0; 400177957Sattilio lk->lk_timo = timo; 401177957Sattilio lk->lk_pri = pri; 402177957Sattilio lock_init(&lk->lock_object, &lock_class_lockmgr, wmesg, NULL, iflags); 403177957Sattilio STACK_ZERO(lk); 40428345Sdyson} 40524269Speter 406211531Sjhb/* 407211531Sjhb * XXX: Gross hacks to manipulate external lock flags after 408211531Sjhb * initialization. Used for certain vnode and buf locks. 409211531Sjhb */ 410177957Sattiliovoid 411211531Sjhblockallowshare(struct lock *lk) 412211531Sjhb{ 413211531Sjhb 414211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 415211531Sjhb lk->lock_object.lo_flags &= ~LK_NOSHARE; 416211531Sjhb} 417211531Sjhb 418211531Sjhbvoid 419211531Sjhblockallowrecurse(struct lock *lk) 420211531Sjhb{ 421211531Sjhb 422211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 423211531Sjhb lk->lock_object.lo_flags |= LO_RECURSABLE; 424211531Sjhb} 425211531Sjhb 426211531Sjhbvoid 427211531Sjhblockdisablerecurse(struct lock *lk) 428211531Sjhb{ 429211531Sjhb 430211531Sjhb lockmgr_assert(lk, KA_XLOCKED); 431211531Sjhb lk->lock_object.lo_flags &= ~LO_RECURSABLE; 432211531Sjhb} 433211531Sjhb 434211531Sjhbvoid 435177957Sattiliolockdestroy(struct lock *lk) 436177957Sattilio{ 43742453Seivind 438177957Sattilio KASSERT(lk->lk_lock == LK_UNLOCKED, ("lockmgr still held")); 439177957Sattilio KASSERT(lk->lk_recurse == 0, ("lockmgr still recursed")); 440200447Sattilio KASSERT(lk->lk_exslpfail == 0, ("lockmgr still exclusive waiters")); 441177957Sattilio lock_destroy(&lk->lock_object); 44228345Sdyson} 44328345Sdyson 444177957Sattilioint 445177957Sattilio__lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk, 446177957Sattilio const char *wmesg, int pri, int timo, const char *file, int line) 447140711Sjeff{ 448178159Sattilio GIANT_DECLARE; 449177957Sattilio struct lock_class *class; 450176320Sattilio const char *iwmesg; 451177957Sattilio uintptr_t tid, v, x; 452200447Sattilio u_int op, realexslp; 453189846Sjeff int error, ipri, itimo, queue, wakeup_swapper; 454189846Sjeff#ifdef LOCK_PROFILING 455189846Sjeff uint64_t waittime = 0; 456189846Sjeff int contested = 0; 457189846Sjeff#endif 458194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 459194317Sattilio volatile struct thread *owner; 460194317Sattilio u_int i, spintries = 0; 461194317Sattilio#endif 462176320Sattilio 463177957Sattilio error = 0; 464177957Sattilio tid = (uintptr_t)curthread; 465177957Sattilio op = (flags & LK_TYPE_MASK); 466177957Sattilio iwmesg = (wmesg == LK_WMESG_DEFAULT) ? lk->lock_object.lo_name : wmesg; 467177957Sattilio ipri = (pri == LK_PRIO_DEFAULT) ? lk->lk_pri : pri; 468177957Sattilio itimo = (timo == LK_TIMO_DEFAULT) ? lk->lk_timo : timo; 469176320Sattilio 470177957Sattilio MPASS((flags & ~LK_TOTAL_MASK) == 0); 471178150Sattilio KASSERT((op & (op - 1)) == 0, 472178150Sattilio ("%s: Invalid requested operation @ %s:%d", __func__, file, line)); 473177957Sattilio KASSERT((flags & (LK_NOWAIT | LK_SLEEPFAIL)) == 0 || 474177957Sattilio (op != LK_DOWNGRADE && op != LK_RELEASE), 475177957Sattilio ("%s: Invalid flags in regard of the operation desired @ %s:%d", 476177957Sattilio __func__, file, line)); 477177957Sattilio KASSERT((flags & LK_INTERLOCK) == 0 || ilk != NULL, 478177957Sattilio ("%s: LK_INTERLOCK passed without valid interlock @ %s:%d", 479177957Sattilio __func__, file, line)); 480240424Sattilio KASSERT(!TD_IS_IDLETHREAD(curthread), 481240424Sattilio ("%s: idle thread %p on lockmgr %s @ %s:%d", __func__, curthread, 482240424Sattilio lk->lock_object.lo_name, file, line)); 48366615Sjasone 484177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 485177957Sattilio if (panicstr != NULL) { 486177957Sattilio if (flags & LK_INTERLOCK) 487177957Sattilio class->lc_unlock(ilk); 488177957Sattilio return (0); 48928345Sdyson } 49028345Sdyson 491224581Skib if (lk->lock_object.lo_flags & LK_NOSHARE) { 492224581Skib switch (op) { 493224581Skib case LK_SHARED: 494224581Skib op = LK_EXCLUSIVE; 495224581Skib break; 496224581Skib case LK_UPGRADE: 497224581Skib case LK_DOWNGRADE: 498224581Skib _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, 499224581Skib file, line); 500224581Skib return (0); 501224581Skib } 502224581Skib } 503164159Skmacy 504181334Sjhb wakeup_swapper = 0; 505177957Sattilio switch (op) { 506177957Sattilio case LK_SHARED: 507178159Sattilio if (LK_CAN_WITNESS(flags)) 508178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, 509182914Sjhb file, line, ilk); 510177957Sattilio for (;;) { 511177957Sattilio x = lk->lk_lock; 512174948Sattilio 513177957Sattilio /* 514177957Sattilio * If no other thread has an exclusive lock, or 515177957Sattilio * no exclusive waiter is present, bump the count of 516177957Sattilio * sharers. Since we have to preserve the state of 517177957Sattilio * waiters, if we fail to acquire the shared lock 518177957Sattilio * loop back and retry. 519177957Sattilio */ 520177957Sattilio if (LK_CAN_SHARE(x)) { 521177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 522177957Sattilio x + LK_ONE_SHARER)) 523177957Sattilio break; 524177957Sattilio continue; 525177957Sattilio } 526233628Sfabient#ifdef HWPMC_HOOKS 527233628Sfabient PMC_SOFT_CALL( , , lock, failed); 528233628Sfabient#endif 529177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 530177957Sattilio &contested, &waittime); 53128345Sdyson 532177957Sattilio /* 533180798Skib * If the lock is already held by curthread in 534177957Sattilio * exclusive way avoid a deadlock. 535177957Sattilio */ 536177957Sattilio if (LK_HOLDER(x) == tid) { 537177957Sattilio LOCK_LOG2(lk, 538180798Skib "%s: %p already held in exclusive mode", 539177957Sattilio __func__, lk); 540177957Sattilio error = EDEADLK; 541177957Sattilio break; 542177957Sattilio } 543140711Sjeff 544177957Sattilio /* 545177957Sattilio * If the lock is expected to not sleep just give up 546177957Sattilio * and return. 547177957Sattilio */ 548177957Sattilio if (LK_TRYOP(flags)) { 549177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 550177957Sattilio __func__, lk); 551177957Sattilio error = EBUSY; 552177957Sattilio break; 553177957Sattilio } 55428345Sdyson 555194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 556177957Sattilio /* 557194317Sattilio * If the owner is running on another CPU, spin until 558194317Sattilio * the owner stops running or the state of the lock 559196772Sattilio * changes. We need a double-state handle here 560196772Sattilio * because for a failed acquisition the lock can be 561196772Sattilio * either held in exclusive mode or shared mode 562196772Sattilio * (for the writer starvation avoidance technique). 563194317Sattilio */ 564194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 565194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 566194317Sattilio owner = (struct thread *)LK_HOLDER(x); 567194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 568194317Sattilio CTR3(KTR_LOCK, 569194317Sattilio "%s: spinning on %p held by %p", 570194317Sattilio __func__, lk, owner); 571194317Sattilio 572194317Sattilio /* 573194317Sattilio * If we are holding also an interlock drop it 574194317Sattilio * in order to avoid a deadlock if the lockmgr 575194317Sattilio * owner is adaptively spinning on the 576194317Sattilio * interlock itself. 577194317Sattilio */ 578194317Sattilio if (flags & LK_INTERLOCK) { 579194317Sattilio class->lc_unlock(ilk); 580194317Sattilio flags &= ~LK_INTERLOCK; 581194317Sattilio } 582194317Sattilio GIANT_SAVE(); 583194317Sattilio while (LK_HOLDER(lk->lk_lock) == 584194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 585194317Sattilio cpu_spinwait(); 586196772Sattilio GIANT_RESTORE(); 587196772Sattilio continue; 588194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 589196772Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 590194317Sattilio spintries < alk_retries) { 591194317Sattilio if (flags & LK_INTERLOCK) { 592194317Sattilio class->lc_unlock(ilk); 593194317Sattilio flags &= ~LK_INTERLOCK; 594194317Sattilio } 595194317Sattilio GIANT_SAVE(); 596194317Sattilio spintries++; 597194317Sattilio for (i = 0; i < alk_loops; i++) { 598194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 599194317Sattilio CTR4(KTR_LOCK, 600194317Sattilio "%s: shared spinning on %p with %u and %u", 601194317Sattilio __func__, lk, spintries, i); 602194317Sattilio x = lk->lk_lock; 603194317Sattilio if ((x & LK_SHARE) == 0 || 604194317Sattilio LK_CAN_SHARE(x) != 0) 605194317Sattilio break; 606194317Sattilio cpu_spinwait(); 607194317Sattilio } 608196772Sattilio GIANT_RESTORE(); 609194317Sattilio if (i != alk_loops) 610194317Sattilio continue; 611194317Sattilio } 612194317Sattilio#endif 613194317Sattilio 614194317Sattilio /* 615177957Sattilio * Acquire the sleepqueue chain lock because we 616177957Sattilio * probabilly will need to manipulate waiters flags. 617177957Sattilio */ 618177957Sattilio sleepq_lock(&lk->lock_object); 619177957Sattilio x = lk->lk_lock; 620111463Sjeff 621177957Sattilio /* 622177957Sattilio * if the lock can be acquired in shared mode, try 623177957Sattilio * again. 624177957Sattilio */ 625177957Sattilio if (LK_CAN_SHARE(x)) { 626177957Sattilio sleepq_release(&lk->lock_object); 627177957Sattilio continue; 628177957Sattilio } 62924269Speter 630194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 631177957Sattilio /* 632194317Sattilio * The current lock owner might have started executing 633194317Sattilio * on another CPU (or the lock could have changed 634194317Sattilio * owner) while we were waiting on the turnstile 635194317Sattilio * chain lock. If so, drop the turnstile lock and try 636194317Sattilio * again. 637194317Sattilio */ 638194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 639194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 640194317Sattilio owner = (struct thread *)LK_HOLDER(x); 641194317Sattilio if (TD_IS_RUNNING(owner)) { 642194317Sattilio sleepq_release(&lk->lock_object); 643194317Sattilio continue; 644194317Sattilio } 645194317Sattilio } 646194317Sattilio#endif 647194317Sattilio 648194317Sattilio /* 649177957Sattilio * Try to set the LK_SHARED_WAITERS flag. If we fail, 650177957Sattilio * loop back and retry. 651177957Sattilio */ 652177957Sattilio if ((x & LK_SHARED_WAITERS) == 0) { 653177957Sattilio if (!atomic_cmpset_acq_ptr(&lk->lk_lock, x, 654177957Sattilio x | LK_SHARED_WAITERS)) { 655177957Sattilio sleepq_release(&lk->lock_object); 656177957Sattilio continue; 657177957Sattilio } 658177957Sattilio LOCK_LOG2(lk, "%s: %p set shared waiters flag", 659177957Sattilio __func__, lk); 660177957Sattilio } 66124269Speter 662177957Sattilio /* 663177957Sattilio * As far as we have been unable to acquire the 664177957Sattilio * shared lock and the shared waiters flag is set, 665177957Sattilio * we will sleep. 666177957Sattilio */ 667177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 668177957Sattilio SQ_SHARED_QUEUE); 669177957Sattilio flags &= ~LK_INTERLOCK; 670177957Sattilio if (error) { 671177957Sattilio LOCK_LOG3(lk, 672177957Sattilio "%s: interrupted sleep for %p with %d", 673177957Sattilio __func__, lk, error); 674177957Sattilio break; 675177957Sattilio } 676177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 677177957Sattilio __func__, lk); 678177957Sattilio } 679177957Sattilio if (error == 0) { 680177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 681177957Sattilio contested, waittime, file, line); 682177957Sattilio LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, file, 683176014Sattilio line); 684178159Sattilio WITNESS_LOCK(&lk->lock_object, LK_TRYWIT(flags), file, 685178159Sattilio line); 686177957Sattilio TD_LOCKS_INC(curthread); 687177957Sattilio TD_SLOCKS_INC(curthread); 688177957Sattilio STACK_SAVE(lk); 689177957Sattilio } 690177957Sattilio break; 691177957Sattilio case LK_UPGRADE: 692177957Sattilio _lockmgr_assert(lk, KA_SLOCKED, file, line); 693194317Sattilio v = lk->lk_lock; 694194317Sattilio x = v & LK_ALL_WAITERS; 695194317Sattilio v &= LK_EXCLUSIVE_SPINNERS; 696177957Sattilio 69744681Sjulian /* 698177957Sattilio * Try to switch from one shared lock to an exclusive one. 699177957Sattilio * We need to preserve waiters flags during the operation. 70044681Sjulian */ 701194317Sattilio if (atomic_cmpset_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x | v, 702177957Sattilio tid | x)) { 703177957Sattilio LOCK_LOG_LOCK("XUPGRADE", &lk->lock_object, 0, 0, file, 704177957Sattilio line); 705178159Sattilio WITNESS_UPGRADE(&lk->lock_object, LOP_EXCLUSIVE | 706178159Sattilio LK_TRYWIT(flags), file, line); 707177957Sattilio TD_SLOCKS_DEC(curthread); 70824269Speter break; 70924269Speter } 710177957Sattilio 71124269Speter /* 712177957Sattilio * We have been unable to succeed in upgrading, so just 713177957Sattilio * give up the shared lock. 71424269Speter */ 715182010Sjhb wakeup_swapper |= wakeupshlk(lk, file, line); 71624269Speter 717177957Sattilio /* FALLTHROUGH */ 718177957Sattilio case LK_EXCLUSIVE: 719178159Sattilio if (LK_CAN_WITNESS(flags)) 720178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 721182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 72224269Speter 72324269Speter /* 724180798Skib * If curthread already holds the lock and this one is 725177957Sattilio * allowed to recurse, simply recurse on it. 72624269Speter */ 727177957Sattilio if (lockmgr_xlocked(lk)) { 728177957Sattilio if ((flags & LK_CANRECURSE) == 0 && 729193307Sattilio (lk->lock_object.lo_flags & LO_RECURSABLE) == 0) { 730177957Sattilio 731177957Sattilio /* 732177957Sattilio * If the lock is expected to not panic just 733177957Sattilio * give up and return. 734177957Sattilio */ 735177957Sattilio if (LK_TRYOP(flags)) { 736177957Sattilio LOCK_LOG2(lk, 737177957Sattilio "%s: %p fails the try operation", 738177957Sattilio __func__, lk); 739177957Sattilio error = EBUSY; 740177957Sattilio break; 741177957Sattilio } 742177957Sattilio if (flags & LK_INTERLOCK) 743177957Sattilio class->lc_unlock(ilk); 744177957Sattilio panic("%s: recursing on non recursive lockmgr %s @ %s:%d\n", 745177957Sattilio __func__, iwmesg, file, line); 746177957Sattilio } 747177957Sattilio lk->lk_recurse++; 748177957Sattilio LOCK_LOG2(lk, "%s: %p recursing", __func__, lk); 749177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 750177957Sattilio lk->lk_recurse, file, line); 751178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 752178159Sattilio LK_TRYWIT(flags), file, line); 753177957Sattilio TD_LOCKS_INC(curthread); 75424269Speter break; 75524269Speter } 756177957Sattilio 757177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, 758177957Sattilio tid)) { 759233628Sfabient#ifdef HWPMC_HOOKS 760233628Sfabient PMC_SOFT_CALL( , , lock, failed); 761233628Sfabient#endif 762177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 763177957Sattilio &contested, &waittime); 764177957Sattilio 76524269Speter /* 766177957Sattilio * If the lock is expected to not sleep just give up 767177957Sattilio * and return. 76824269Speter */ 769177957Sattilio if (LK_TRYOP(flags)) { 770177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 771177957Sattilio __func__, lk); 772177957Sattilio error = EBUSY; 773177957Sattilio break; 774177957Sattilio } 77534194Sdyson 776194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 777177957Sattilio /* 778194317Sattilio * If the owner is running on another CPU, spin until 779194317Sattilio * the owner stops running or the state of the lock 780194317Sattilio * changes. 781194317Sattilio */ 782194317Sattilio x = lk->lk_lock; 783194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 784194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 785194317Sattilio owner = (struct thread *)LK_HOLDER(x); 786194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 787194317Sattilio CTR3(KTR_LOCK, 788194317Sattilio "%s: spinning on %p held by %p", 789194317Sattilio __func__, lk, owner); 790194317Sattilio 791194317Sattilio /* 792194317Sattilio * If we are holding also an interlock drop it 793194317Sattilio * in order to avoid a deadlock if the lockmgr 794194317Sattilio * owner is adaptively spinning on the 795194317Sattilio * interlock itself. 796194317Sattilio */ 797194317Sattilio if (flags & LK_INTERLOCK) { 798194317Sattilio class->lc_unlock(ilk); 799194317Sattilio flags &= ~LK_INTERLOCK; 800194317Sattilio } 801194317Sattilio GIANT_SAVE(); 802194317Sattilio while (LK_HOLDER(lk->lk_lock) == 803194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 804194317Sattilio cpu_spinwait(); 805196772Sattilio GIANT_RESTORE(); 806196772Sattilio continue; 807194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 808194317Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 809194317Sattilio spintries < alk_retries) { 810194317Sattilio if ((x & LK_EXCLUSIVE_SPINNERS) == 0 && 811194317Sattilio !atomic_cmpset_ptr(&lk->lk_lock, x, 812194317Sattilio x | LK_EXCLUSIVE_SPINNERS)) 813194317Sattilio continue; 814194317Sattilio if (flags & LK_INTERLOCK) { 815194317Sattilio class->lc_unlock(ilk); 816194317Sattilio flags &= ~LK_INTERLOCK; 817194317Sattilio } 818194317Sattilio GIANT_SAVE(); 819194317Sattilio spintries++; 820194317Sattilio for (i = 0; i < alk_loops; i++) { 821194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 822194317Sattilio CTR4(KTR_LOCK, 823194317Sattilio "%s: shared spinning on %p with %u and %u", 824194317Sattilio __func__, lk, spintries, i); 825194317Sattilio if ((lk->lk_lock & 826194317Sattilio LK_EXCLUSIVE_SPINNERS) == 0) 827194317Sattilio break; 828194317Sattilio cpu_spinwait(); 829194317Sattilio } 830196772Sattilio GIANT_RESTORE(); 831194317Sattilio if (i != alk_loops) 832194317Sattilio continue; 833194317Sattilio } 834194317Sattilio#endif 835194317Sattilio 836194317Sattilio /* 837177957Sattilio * Acquire the sleepqueue chain lock because we 838177957Sattilio * probabilly will need to manipulate waiters flags. 839177957Sattilio */ 840177957Sattilio sleepq_lock(&lk->lock_object); 841177957Sattilio x = lk->lk_lock; 842177957Sattilio 843177957Sattilio /* 844177957Sattilio * if the lock has been released while we spun on 845177957Sattilio * the sleepqueue chain lock just try again. 846177957Sattilio */ 847177957Sattilio if (x == LK_UNLOCKED) { 848177957Sattilio sleepq_release(&lk->lock_object); 849177957Sattilio continue; 850134365Skan } 85124269Speter 852194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 85324269Speter /* 854194317Sattilio * The current lock owner might have started executing 855194317Sattilio * on another CPU (or the lock could have changed 856194317Sattilio * owner) while we were waiting on the turnstile 857194317Sattilio * chain lock. If so, drop the turnstile lock and try 858194317Sattilio * again. 859194317Sattilio */ 860194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 861194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 862194317Sattilio owner = (struct thread *)LK_HOLDER(x); 863194317Sattilio if (TD_IS_RUNNING(owner)) { 864194317Sattilio sleepq_release(&lk->lock_object); 865194317Sattilio continue; 866194317Sattilio } 867194317Sattilio } 868194317Sattilio#endif 869194317Sattilio 870194317Sattilio /* 871177957Sattilio * The lock can be in the state where there is a 872177957Sattilio * pending queue of waiters, but still no owner. 873177957Sattilio * This happens when the lock is contested and an 874177957Sattilio * owner is going to claim the lock. 875177957Sattilio * If curthread is the one successfully acquiring it 876177957Sattilio * claim lock ownership and return, preserving waiters 877177957Sattilio * flags. 87824269Speter */ 879194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 880194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 881194317Sattilio v &= ~LK_EXCLUSIVE_SPINNERS; 882177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 883177957Sattilio tid | v)) { 884177957Sattilio sleepq_release(&lk->lock_object); 885177957Sattilio LOCK_LOG2(lk, 886177957Sattilio "%s: %p claimed by a new writer", 887177957Sattilio __func__, lk); 888177957Sattilio break; 889177957Sattilio } 890177957Sattilio sleepq_release(&lk->lock_object); 891177957Sattilio continue; 892177957Sattilio } 893177957Sattilio 894177957Sattilio /* 895177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 896177957Sattilio * fail, loop back and retry. 897177957Sattilio */ 898177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 899177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 900177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 901177957Sattilio sleepq_release(&lk->lock_object); 902177957Sattilio continue; 903177957Sattilio } 904177957Sattilio LOCK_LOG2(lk, "%s: %p set excl waiters flag", 905177957Sattilio __func__, lk); 906177957Sattilio } 907177957Sattilio 908177957Sattilio /* 909177957Sattilio * As far as we have been unable to acquire the 910177957Sattilio * exclusive lock and the exclusive waiters flag 911177957Sattilio * is set, we will sleep. 912177957Sattilio */ 913177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 914177957Sattilio SQ_EXCLUSIVE_QUEUE); 915177957Sattilio flags &= ~LK_INTERLOCK; 916177957Sattilio if (error) { 917177957Sattilio LOCK_LOG3(lk, 918177957Sattilio "%s: interrupted sleep for %p with %d", 919177957Sattilio __func__, lk, error); 92048301Smckusick break; 92148301Smckusick } 922177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 923177957Sattilio __func__, lk); 92424269Speter } 925177957Sattilio if (error == 0) { 926177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 927177957Sattilio contested, waittime, file, line); 928177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 929177957Sattilio lk->lk_recurse, file, line); 930178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 931178159Sattilio LK_TRYWIT(flags), file, line); 932177957Sattilio TD_LOCKS_INC(curthread); 933177957Sattilio STACK_SAVE(lk); 934177957Sattilio } 935177957Sattilio break; 936177957Sattilio case LK_DOWNGRADE: 937243900Sattilio _lockmgr_assert(lk, KA_XLOCKED, file, line); 938178159Sattilio LOCK_LOG_LOCK("XDOWNGRADE", &lk->lock_object, 0, 0, file, line); 939178159Sattilio WITNESS_DOWNGRADE(&lk->lock_object, 0, file, line); 940243900Sattilio 941243900Sattilio /* 942243900Sattilio * Panic if the lock is recursed. 943243900Sattilio */ 944243900Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) { 945243900Sattilio if (flags & LK_INTERLOCK) 946243900Sattilio class->lc_unlock(ilk); 947243900Sattilio panic("%s: downgrade a recursed lockmgr %s @ %s:%d\n", 948243900Sattilio __func__, iwmesg, file, line); 949243900Sattilio } 950178159Sattilio TD_SLOCKS_INC(curthread); 951177957Sattilio 95224269Speter /* 953177957Sattilio * In order to preserve waiters flags, just spin. 95424269Speter */ 955177957Sattilio for (;;) { 956194317Sattilio x = lk->lk_lock; 957194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 958194317Sattilio x &= LK_ALL_WAITERS; 959177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 960178159Sattilio LK_SHARERS_LOCK(1) | x)) 961177957Sattilio break; 962177957Sattilio cpu_spinwait(); 96324269Speter } 96424269Speter break; 965177957Sattilio case LK_RELEASE: 966177957Sattilio _lockmgr_assert(lk, KA_LOCKED, file, line); 967177957Sattilio x = lk->lk_lock; 96824269Speter 969177957Sattilio if ((x & LK_SHARE) == 0) { 970177957Sattilio 971177957Sattilio /* 972177957Sattilio * As first option, treact the lock as if it has not 973177957Sattilio * any waiter. 974177957Sattilio * Fix-up the tid var if the lock has been disowned. 975177957Sattilio */ 976177957Sattilio if (LK_HOLDER(x) == LK_KERNPROC) 977177957Sattilio tid = LK_KERNPROC; 978178159Sattilio else { 979178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, 980178159Sattilio file, line); 981177957Sattilio TD_LOCKS_DEC(curthread); 982178159Sattilio } 983177957Sattilio LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, 984177957Sattilio lk->lk_recurse, file, line); 985177957Sattilio 986177957Sattilio /* 987177957Sattilio * The lock is held in exclusive mode. 988177957Sattilio * If the lock is recursed also, then unrecurse it. 989177957Sattilio */ 990177957Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) { 991177957Sattilio LOCK_LOG2(lk, "%s: %p unrecursing", __func__, 992177957Sattilio lk); 993177957Sattilio lk->lk_recurse--; 994177957Sattilio break; 995176014Sattilio } 996189788Sjeff if (tid != LK_KERNPROC) 997189788Sjeff lock_profile_release_lock(&lk->lock_object); 998177957Sattilio 999177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid, 1000177957Sattilio LK_UNLOCKED)) 1001177957Sattilio break; 1002177957Sattilio 1003177957Sattilio sleepq_lock(&lk->lock_object); 1004194317Sattilio x = lk->lk_lock; 1005177957Sattilio v = LK_UNLOCKED; 1006177957Sattilio 1007177957Sattilio /* 1008177957Sattilio * If the lock has exclusive waiters, give them 1009177957Sattilio * preference in order to avoid deadlock with 1010177957Sattilio * shared runners up. 1011200447Sattilio * If interruptible sleeps left the exclusive queue 1012200447Sattilio * empty avoid a starvation for the threads sleeping 1013200447Sattilio * on the shared queue by giving them precedence 1014200447Sattilio * and cleaning up the exclusive waiters bit anyway. 1015201709Sattilio * Please note that lk_exslpfail count may be lying 1016201709Sattilio * about the real number of waiters with the 1017201709Sattilio * LK_SLEEPFAIL flag on because they may be used in 1018201709Sattilio * conjuction with interruptible sleeps so 1019201710Sattilio * lk_exslpfail might be considered an 'upper limit' 1020201710Sattilio * bound, including the edge cases. 1021177957Sattilio */ 1022194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1023200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 1024200447Sattilio SQ_EXCLUSIVE_QUEUE); 1025200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 1026200447Sattilio if (lk->lk_exslpfail < realexslp) { 1027200447Sattilio lk->lk_exslpfail = 0; 1028200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1029200447Sattilio v |= (x & LK_SHARED_WAITERS); 1030200447Sattilio } else { 1031200447Sattilio lk->lk_exslpfail = 0; 1032200447Sattilio LOCK_LOG2(lk, 1033200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1034200447Sattilio __func__, lk); 1035200447Sattilio LOCK_LOG2(lk, 1036200447Sattilio "%s: %p waking up threads on the exclusive queue", 1037200447Sattilio __func__, lk); 1038200447Sattilio wakeup_swapper = 1039200447Sattilio sleepq_broadcast(&lk->lock_object, 1040200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 1041200447Sattilio queue = SQ_SHARED_QUEUE; 1042200447Sattilio } 1043177957Sattilio } else { 1044201703Sattilio 1045201703Sattilio /* 1046201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL 1047201703Sattilio * on and using interruptible sleeps/timeout 1048201703Sattilio * may have left spourious lk_exslpfail counts 1049201703Sattilio * on, so clean it up anyway. 1050201703Sattilio */ 1051201703Sattilio lk->lk_exslpfail = 0; 1052177957Sattilio queue = SQ_SHARED_QUEUE; 105324269Speter } 1054149723Sssouhlal 1055177957Sattilio LOCK_LOG3(lk, 1056177957Sattilio "%s: %p waking up threads on the %s queue", 1057177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 1058177957Sattilio "exclusive"); 1059177957Sattilio atomic_store_rel_ptr(&lk->lk_lock, v); 1060200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, 1061181334Sjhb SLEEPQ_LK, 0, queue); 1062177957Sattilio sleepq_release(&lk->lock_object); 1063177957Sattilio break; 1064177957Sattilio } else 1065181334Sjhb wakeup_swapper = wakeupshlk(lk, file, line); 106624269Speter break; 1067177957Sattilio case LK_DRAIN: 1068178159Sattilio if (LK_CAN_WITNESS(flags)) 1069178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 1070182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 107124269Speter 107224269Speter /* 1073180798Skib * Trying to drain a lock we already own will result in a 1074177957Sattilio * deadlock. 107524269Speter */ 1076177957Sattilio if (lockmgr_xlocked(lk)) { 1077177957Sattilio if (flags & LK_INTERLOCK) 1078177957Sattilio class->lc_unlock(ilk); 1079177957Sattilio panic("%s: draining %s with the lock held @ %s:%d\n", 1080177957Sattilio __func__, iwmesg, file, line); 1081177957Sattilio } 108228345Sdyson 1083177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) { 1084233628Sfabient#ifdef HWPMC_HOOKS 1085233628Sfabient PMC_SOFT_CALL( , , lock, failed); 1086233628Sfabient#endif 1087177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 1088177957Sattilio &contested, &waittime); 108924269Speter 1090177957Sattilio /* 1091177957Sattilio * If the lock is expected to not sleep just give up 1092177957Sattilio * and return. 1093177957Sattilio */ 1094177957Sattilio if (LK_TRYOP(flags)) { 1095177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 1096177957Sattilio __func__, lk); 1097177957Sattilio error = EBUSY; 1098177957Sattilio break; 1099177957Sattilio } 110024269Speter 1101177957Sattilio /* 1102177957Sattilio * Acquire the sleepqueue chain lock because we 1103177957Sattilio * probabilly will need to manipulate waiters flags. 1104177957Sattilio */ 1105177957Sattilio sleepq_lock(&lk->lock_object); 1106177957Sattilio x = lk->lk_lock; 110729653Sdyson 1108177957Sattilio /* 1109177957Sattilio * if the lock has been released while we spun on 1110177957Sattilio * the sleepqueue chain lock just try again. 1111177957Sattilio */ 1112177957Sattilio if (x == LK_UNLOCKED) { 1113177957Sattilio sleepq_release(&lk->lock_object); 1114177957Sattilio continue; 1115177957Sattilio } 1116176320Sattilio 1117194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 1118194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 1119194317Sattilio v = (x & ~LK_EXCLUSIVE_SPINNERS); 1120200447Sattilio 1121200447Sattilio /* 1122200447Sattilio * If interruptible sleeps left the exclusive 1123200447Sattilio * queue empty avoid a starvation for the 1124200447Sattilio * threads sleeping on the shared queue by 1125200447Sattilio * giving them precedence and cleaning up the 1126200447Sattilio * exclusive waiters bit anyway. 1127201709Sattilio * Please note that lk_exslpfail count may be 1128201709Sattilio * lying about the real number of waiters with 1129201709Sattilio * the LK_SLEEPFAIL flag on because they may 1130201709Sattilio * be used in conjuction with interruptible 1131201710Sattilio * sleeps so lk_exslpfail might be considered 1132201710Sattilio * an 'upper limit' bound, including the edge 1133201709Sattilio * cases. 1134200447Sattilio */ 1135177957Sattilio if (v & LK_EXCLUSIVE_WAITERS) { 1136177957Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1137177957Sattilio v &= ~LK_EXCLUSIVE_WAITERS; 1138177957Sattilio } else { 1139201703Sattilio 1140201703Sattilio /* 1141201703Sattilio * Exclusive waiters sleeping with 1142201703Sattilio * LK_SLEEPFAIL on and using 1143201703Sattilio * interruptible sleeps/timeout may 1144201703Sattilio * have left spourious lk_exslpfail 1145201703Sattilio * counts on, so clean it up anyway. 1146201703Sattilio */ 1147177957Sattilio MPASS(v & LK_SHARED_WAITERS); 1148201703Sattilio lk->lk_exslpfail = 0; 1149177957Sattilio queue = SQ_SHARED_QUEUE; 1150177957Sattilio v &= ~LK_SHARED_WAITERS; 1151177957Sattilio } 1152200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE) { 1153200447Sattilio realexslp = 1154200447Sattilio sleepq_sleepcnt(&lk->lock_object, 1155200447Sattilio SQ_EXCLUSIVE_QUEUE); 1156200447Sattilio if (lk->lk_exslpfail >= realexslp) { 1157200447Sattilio lk->lk_exslpfail = 0; 1158200447Sattilio queue = SQ_SHARED_QUEUE; 1159200447Sattilio v &= ~LK_SHARED_WAITERS; 1160200447Sattilio if (realexslp != 0) { 1161200447Sattilio LOCK_LOG2(lk, 1162200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1163200447Sattilio __func__, lk); 1164200447Sattilio LOCK_LOG2(lk, 1165200447Sattilio "%s: %p waking up threads on the exclusive queue", 1166200447Sattilio __func__, lk); 1167200447Sattilio wakeup_swapper = 1168200447Sattilio sleepq_broadcast( 1169200447Sattilio &lk->lock_object, 1170200447Sattilio SLEEPQ_LK, 0, 1171200447Sattilio SQ_EXCLUSIVE_QUEUE); 1172200447Sattilio } 1173200447Sattilio } else 1174200447Sattilio lk->lk_exslpfail = 0; 1175200447Sattilio } 1176177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, v)) { 1177177957Sattilio sleepq_release(&lk->lock_object); 1178177957Sattilio continue; 1179177957Sattilio } 1180177957Sattilio LOCK_LOG3(lk, 1181177957Sattilio "%s: %p waking up all threads on the %s queue", 1182177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? 1183177957Sattilio "shared" : "exclusive"); 1184182010Sjhb wakeup_swapper |= sleepq_broadcast( 1185181334Sjhb &lk->lock_object, SLEEPQ_LK, 0, queue); 1186177957Sattilio 1187177957Sattilio /* 1188177957Sattilio * If shared waiters have been woken up we need 1189177957Sattilio * to wait for one of them to acquire the lock 1190177957Sattilio * before to set the exclusive waiters in 1191177957Sattilio * order to avoid a deadlock. 1192177957Sattilio */ 1193177957Sattilio if (queue == SQ_SHARED_QUEUE) { 1194177957Sattilio for (v = lk->lk_lock; 1195177957Sattilio (v & LK_SHARE) && !LK_SHARERS(v); 1196177957Sattilio v = lk->lk_lock) 1197177957Sattilio cpu_spinwait(); 1198177957Sattilio } 1199177957Sattilio } 1200177957Sattilio 1201177957Sattilio /* 1202177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 1203177957Sattilio * fail, loop back and retry. 1204177957Sattilio */ 1205177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 1206177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 1207177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 1208177957Sattilio sleepq_release(&lk->lock_object); 1209177957Sattilio continue; 1210177957Sattilio } 1211177957Sattilio LOCK_LOG2(lk, "%s: %p set drain waiters flag", 1212177957Sattilio __func__, lk); 1213177957Sattilio } 1214177957Sattilio 1215177957Sattilio /* 1216177957Sattilio * As far as we have been unable to acquire the 1217177957Sattilio * exclusive lock and the exclusive waiters flag 1218177957Sattilio * is set, we will sleep. 1219177957Sattilio */ 1220177957Sattilio if (flags & LK_INTERLOCK) { 1221177957Sattilio class->lc_unlock(ilk); 1222177957Sattilio flags &= ~LK_INTERLOCK; 1223177957Sattilio } 1224178159Sattilio GIANT_SAVE(); 1225177957Sattilio sleepq_add(&lk->lock_object, NULL, iwmesg, SLEEPQ_LK, 1226177957Sattilio SQ_EXCLUSIVE_QUEUE); 1227177957Sattilio sleepq_wait(&lk->lock_object, ipri & PRIMASK); 1228178159Sattilio GIANT_RESTORE(); 1229177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 1230177957Sattilio __func__, lk); 123129653Sdyson } 1232177957Sattilio 1233177957Sattilio if (error == 0) { 1234177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 1235177957Sattilio contested, waittime, file, line); 1236177957Sattilio LOCK_LOG_LOCK("DRAIN", &lk->lock_object, 0, 1237177957Sattilio lk->lk_recurse, file, line); 1238178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 1239178159Sattilio LK_TRYWIT(flags), file, line); 1240177957Sattilio TD_LOCKS_INC(curthread); 1241177957Sattilio STACK_SAVE(lk); 1242177957Sattilio } 1243177957Sattilio break; 1244177957Sattilio default: 1245177957Sattilio if (flags & LK_INTERLOCK) 1246177957Sattilio class->lc_unlock(ilk); 1247177957Sattilio panic("%s: unknown lockmgr request 0x%x\n", __func__, op); 124829653Sdyson } 1249177957Sattilio 1250177957Sattilio if (flags & LK_INTERLOCK) 1251177957Sattilio class->lc_unlock(ilk); 1252181334Sjhb if (wakeup_swapper) 1253181334Sjhb kick_proc0(); 1254177957Sattilio 1255177957Sattilio return (error); 125629653Sdyson} 125729653Sdyson 125829653Sdysonvoid 1259177957Sattilio_lockmgr_disown(struct lock *lk, const char *file, int line) 126029653Sdyson{ 1261177957Sattilio uintptr_t tid, x; 1262176014Sattilio 1263228424Savg if (SCHEDULER_STOPPED()) 1264228424Savg return; 1265228424Savg 1266177957Sattilio tid = (uintptr_t)curthread; 1267243900Sattilio _lockmgr_assert(lk, KA_XLOCKED, file, line); 126829653Sdyson 1269177957Sattilio /* 1270243900Sattilio * Panic if the lock is recursed. 1271243900Sattilio */ 1272243900Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) 1273243900Sattilio panic("%s: disown a recursed lockmgr @ %s:%d\n", 1274243900Sattilio __func__, file, line); 1275243900Sattilio 1276243900Sattilio /* 1277180798Skib * If the owner is already LK_KERNPROC just skip the whole operation. 1278177957Sattilio */ 1279177957Sattilio if (LK_HOLDER(lk->lk_lock) != tid) 1280177957Sattilio return; 1281189788Sjeff lock_profile_release_lock(&lk->lock_object); 1282178159Sattilio LOCK_LOG_LOCK("XDISOWN", &lk->lock_object, 0, 0, file, line); 1283178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); 1284178159Sattilio TD_LOCKS_DEC(curthread); 1285199008Sattilio STACK_SAVE(lk); 128629653Sdyson 1287177957Sattilio /* 1288177957Sattilio * In order to preserve waiters flags, just spin. 1289177957Sattilio */ 1290177957Sattilio for (;;) { 1291194317Sattilio x = lk->lk_lock; 1292194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1293194317Sattilio x &= LK_ALL_WAITERS; 1294178166Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 1295178159Sattilio LK_KERNPROC | x)) 1296177957Sattilio return; 1297177957Sattilio cpu_spinwait(); 1298177957Sattilio } 129966615Sjasone} 130066615Sjasone 1301175166Sattiliovoid 1302227588Spjdlockmgr_printinfo(const struct lock *lk) 1303175166Sattilio{ 1304175166Sattilio struct thread *td; 1305177957Sattilio uintptr_t x; 1306175166Sattilio 1307177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1308188244Sjhb printf("lock type %s: UNLOCKED\n", lk->lock_object.lo_name); 1309177957Sattilio else if (lk->lk_lock & LK_SHARE) 1310188244Sjhb printf("lock type %s: SHARED (count %ju)\n", 1311177957Sattilio lk->lock_object.lo_name, 1312177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1313177957Sattilio else { 1314177957Sattilio td = lockmgr_xholder(lk); 1315232547Sivoras printf("lock type %s: EXCL by thread %p " 1316232547Sivoras "(pid %d, %s, tid %d)\n", lk->lock_object.lo_name, td, 1317232547Sivoras td->td_proc->p_pid, td->td_proc->p_comm, td->td_tid); 1318177957Sattilio } 1319175166Sattilio 1320177957Sattilio x = lk->lk_lock; 1321177957Sattilio if (x & LK_EXCLUSIVE_WAITERS) 1322177957Sattilio printf(" with exclusive waiters pending\n"); 1323177957Sattilio if (x & LK_SHARED_WAITERS) 1324177957Sattilio printf(" with shared waiters pending\n"); 1325194317Sattilio if (x & LK_EXCLUSIVE_SPINNERS) 1326194317Sattilio printf(" with exclusive spinners pending\n"); 1327177957Sattilio 1328177957Sattilio STACK_PRINT(lk); 1329175166Sattilio} 1330175166Sattilio 133129653Sdysonint 1332227588Spjdlockstatus(const struct lock *lk) 133329653Sdyson{ 1334177957Sattilio uintptr_t v, x; 1335177957Sattilio int ret; 133629653Sdyson 1337177957Sattilio ret = LK_SHARED; 1338177957Sattilio x = lk->lk_lock; 1339177957Sattilio v = LK_HOLDER(x); 1340175635Sattilio 1341177957Sattilio if ((x & LK_SHARE) == 0) { 1342177957Sattilio if (v == (uintptr_t)curthread || v == LK_KERNPROC) 1343177957Sattilio ret = LK_EXCLUSIVE; 134454444Seivind else 1345177957Sattilio ret = LK_EXCLOTHER; 1346177957Sattilio } else if (x == LK_UNLOCKED) 1347177957Sattilio ret = 0; 134829653Sdyson 1349177957Sattilio return (ret); 135024269Speter} 1351161322Sjhb 1352176249Sattilio#ifdef INVARIANT_SUPPORT 1353219028Snetchild 1354219028SnetchildFEATURE(invariant_support, 1355219028Snetchild "Support for modules compiled with INVARIANTS option"); 1356219028Snetchild 1357176249Sattilio#ifndef INVARIANTS 1358177957Sattilio#undef _lockmgr_assert 1359176249Sattilio#endif 1360176249Sattilio 1361176249Sattiliovoid 1362227588Spjd_lockmgr_assert(const struct lock *lk, int what, const char *file, int line) 1363176249Sattilio{ 1364176249Sattilio int slocked = 0; 1365176249Sattilio 1366176249Sattilio if (panicstr != NULL) 1367176249Sattilio return; 1368176249Sattilio switch (what) { 1369176249Sattilio case KA_SLOCKED: 1370176249Sattilio case KA_SLOCKED | KA_NOTRECURSED: 1371176249Sattilio case KA_SLOCKED | KA_RECURSED: 1372176249Sattilio slocked = 1; 1373176249Sattilio case KA_LOCKED: 1374176249Sattilio case KA_LOCKED | KA_NOTRECURSED: 1375176249Sattilio case KA_LOCKED | KA_RECURSED: 1376178159Sattilio#ifdef WITNESS 1377178159Sattilio 1378178159Sattilio /* 1379178159Sattilio * We cannot trust WITNESS if the lock is held in exclusive 1380178159Sattilio * mode and a call to lockmgr_disown() happened. 1381178159Sattilio * Workaround this skipping the check if the lock is held in 1382178159Sattilio * exclusive mode even for the KA_LOCKED case. 1383178159Sattilio */ 1384178159Sattilio if (slocked || (lk->lk_lock & LK_SHARE)) { 1385178159Sattilio witness_assert(&lk->lock_object, what, file, line); 1386178159Sattilio break; 1387178159Sattilio } 1388178159Sattilio#endif 1389177957Sattilio if (lk->lk_lock == LK_UNLOCKED || 1390177957Sattilio ((lk->lk_lock & LK_SHARE) == 0 && (slocked || 1391177957Sattilio (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk))))) 1392176249Sattilio panic("Lock %s not %slocked @ %s:%d\n", 1393177957Sattilio lk->lock_object.lo_name, slocked ? "share" : "", 1394176249Sattilio file, line); 1395177957Sattilio 1396177957Sattilio if ((lk->lk_lock & LK_SHARE) == 0) { 1397177957Sattilio if (lockmgr_recursed(lk)) { 1398176249Sattilio if (what & KA_NOTRECURSED) 1399176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1400177957Sattilio lk->lock_object.lo_name, file, 1401177957Sattilio line); 1402176249Sattilio } else if (what & KA_RECURSED) 1403176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1404177957Sattilio lk->lock_object.lo_name, file, line); 1405176249Sattilio } 1406176249Sattilio break; 1407176249Sattilio case KA_XLOCKED: 1408176249Sattilio case KA_XLOCKED | KA_NOTRECURSED: 1409176249Sattilio case KA_XLOCKED | KA_RECURSED: 1410177957Sattilio if (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk)) 1411176249Sattilio panic("Lock %s not exclusively locked @ %s:%d\n", 1412177957Sattilio lk->lock_object.lo_name, file, line); 1413177957Sattilio if (lockmgr_recursed(lk)) { 1414176249Sattilio if (what & KA_NOTRECURSED) 1415176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1416177957Sattilio lk->lock_object.lo_name, file, line); 1417176249Sattilio } else if (what & KA_RECURSED) 1418176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1419177957Sattilio lk->lock_object.lo_name, file, line); 1420176249Sattilio break; 1421176249Sattilio case KA_UNLOCKED: 1422177957Sattilio if (lockmgr_xlocked(lk) || lockmgr_disowned(lk)) 1423176249Sattilio panic("Lock %s exclusively locked @ %s:%d\n", 1424177957Sattilio lk->lock_object.lo_name, file, line); 1425176249Sattilio break; 1426176249Sattilio default: 1427177957Sattilio panic("Unknown lockmgr assertion: %d @ %s:%d\n", what, file, 1428177957Sattilio line); 1429176249Sattilio } 1430176249Sattilio} 1431177957Sattilio#endif 1432176249Sattilio 1433161322Sjhb#ifdef DDB 1434161337Sjhbint 1435161337Sjhblockmgr_chain(struct thread *td, struct thread **ownerp) 1436161337Sjhb{ 1437177957Sattilio struct lock *lk; 1438161337Sjhb 1439177957Sattilio lk = td->td_wchan; 1440161337Sjhb 1441177957Sattilio if (LOCK_CLASS(&lk->lock_object) != &lock_class_lockmgr) 1442177957Sattilio return (0); 1443177957Sattilio db_printf("blocked on lockmgr %s", lk->lock_object.lo_name); 1444177957Sattilio if (lk->lk_lock & LK_SHARE) 1445177957Sattilio db_printf("SHARED (count %ju)\n", 1446177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1447177957Sattilio else 1448177957Sattilio db_printf("EXCL\n"); 1449177957Sattilio *ownerp = lockmgr_xholder(lk); 1450161337Sjhb 1451161337Sjhb return (1); 1452161337Sjhb} 1453161337Sjhb 1454177957Sattiliostatic void 1455227588Spjddb_show_lockmgr(const struct lock_object *lock) 1456161322Sjhb{ 1457161322Sjhb struct thread *td; 1458227588Spjd const struct lock *lk; 1459161322Sjhb 1460227588Spjd lk = (const struct lock *)lock; 1461161322Sjhb 1462168070Sjhb db_printf(" state: "); 1463177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1464161322Sjhb db_printf("UNLOCKED\n"); 1465177957Sattilio else if (lk->lk_lock & LK_SHARE) 1466177957Sattilio db_printf("SLOCK: %ju\n", (uintmax_t)LK_SHARERS(lk->lk_lock)); 1467177957Sattilio else { 1468177957Sattilio td = lockmgr_xholder(lk); 1469177957Sattilio if (td == (struct thread *)LK_KERNPROC) 1470177957Sattilio db_printf("XLOCK: LK_KERNPROC\n"); 1471177957Sattilio else 1472177957Sattilio db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td, 1473177957Sattilio td->td_tid, td->td_proc->p_pid, 1474177957Sattilio td->td_proc->p_comm); 1475177957Sattilio if (lockmgr_recursed(lk)) 1476177957Sattilio db_printf(" recursed: %d\n", lk->lk_recurse); 1477177957Sattilio } 1478177957Sattilio db_printf(" waiters: "); 1479177957Sattilio switch (lk->lk_lock & LK_ALL_WAITERS) { 1480177957Sattilio case LK_SHARED_WAITERS: 1481177957Sattilio db_printf("shared\n"); 1482192022Strasz break; 1483177957Sattilio case LK_EXCLUSIVE_WAITERS: 1484177957Sattilio db_printf("exclusive\n"); 1485177957Sattilio break; 1486177957Sattilio case LK_ALL_WAITERS: 1487177957Sattilio db_printf("shared and exclusive\n"); 1488177957Sattilio break; 1489177957Sattilio default: 1490177957Sattilio db_printf("none\n"); 1491177957Sattilio } 1492194317Sattilio db_printf(" spinners: "); 1493194317Sattilio if (lk->lk_lock & LK_EXCLUSIVE_SPINNERS) 1494194317Sattilio db_printf("exclusive\n"); 1495194317Sattilio else 1496194317Sattilio db_printf("none\n"); 1497161322Sjhb} 1498161322Sjhb#endif 1499