kern_lock.c revision 233628
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 233628 2012-03-28 20:58:30Z fabient $"); 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)); 48066615Sjasone 481177957Sattilio class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL; 482177957Sattilio if (panicstr != NULL) { 483177957Sattilio if (flags & LK_INTERLOCK) 484177957Sattilio class->lc_unlock(ilk); 485177957Sattilio return (0); 48628345Sdyson } 48728345Sdyson 488224581Skib if (lk->lock_object.lo_flags & LK_NOSHARE) { 489224581Skib switch (op) { 490224581Skib case LK_SHARED: 491224581Skib op = LK_EXCLUSIVE; 492224581Skib break; 493224581Skib case LK_UPGRADE: 494224581Skib case LK_DOWNGRADE: 495224581Skib _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, 496224581Skib file, line); 497224581Skib return (0); 498224581Skib } 499224581Skib } 500164159Skmacy 501181334Sjhb wakeup_swapper = 0; 502177957Sattilio switch (op) { 503177957Sattilio case LK_SHARED: 504178159Sattilio if (LK_CAN_WITNESS(flags)) 505178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER, 506182914Sjhb file, line, ilk); 507177957Sattilio for (;;) { 508177957Sattilio x = lk->lk_lock; 509174948Sattilio 510177957Sattilio /* 511177957Sattilio * If no other thread has an exclusive lock, or 512177957Sattilio * no exclusive waiter is present, bump the count of 513177957Sattilio * sharers. Since we have to preserve the state of 514177957Sattilio * waiters, if we fail to acquire the shared lock 515177957Sattilio * loop back and retry. 516177957Sattilio */ 517177957Sattilio if (LK_CAN_SHARE(x)) { 518177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 519177957Sattilio x + LK_ONE_SHARER)) 520177957Sattilio break; 521177957Sattilio continue; 522177957Sattilio } 523233628Sfabient#ifdef HWPMC_HOOKS 524233628Sfabient PMC_SOFT_CALL( , , lock, failed); 525233628Sfabient#endif 526177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 527177957Sattilio &contested, &waittime); 52828345Sdyson 529177957Sattilio /* 530180798Skib * If the lock is already held by curthread in 531177957Sattilio * exclusive way avoid a deadlock. 532177957Sattilio */ 533177957Sattilio if (LK_HOLDER(x) == tid) { 534177957Sattilio LOCK_LOG2(lk, 535180798Skib "%s: %p already held in exclusive mode", 536177957Sattilio __func__, lk); 537177957Sattilio error = EDEADLK; 538177957Sattilio break; 539177957Sattilio } 540140711Sjeff 541177957Sattilio /* 542177957Sattilio * If the lock is expected to not sleep just give up 543177957Sattilio * and return. 544177957Sattilio */ 545177957Sattilio if (LK_TRYOP(flags)) { 546177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 547177957Sattilio __func__, lk); 548177957Sattilio error = EBUSY; 549177957Sattilio break; 550177957Sattilio } 55128345Sdyson 552194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 553177957Sattilio /* 554194317Sattilio * If the owner is running on another CPU, spin until 555194317Sattilio * the owner stops running or the state of the lock 556196772Sattilio * changes. We need a double-state handle here 557196772Sattilio * because for a failed acquisition the lock can be 558196772Sattilio * either held in exclusive mode or shared mode 559196772Sattilio * (for the writer starvation avoidance technique). 560194317Sattilio */ 561194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 562194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 563194317Sattilio owner = (struct thread *)LK_HOLDER(x); 564194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 565194317Sattilio CTR3(KTR_LOCK, 566194317Sattilio "%s: spinning on %p held by %p", 567194317Sattilio __func__, lk, owner); 568194317Sattilio 569194317Sattilio /* 570194317Sattilio * If we are holding also an interlock drop it 571194317Sattilio * in order to avoid a deadlock if the lockmgr 572194317Sattilio * owner is adaptively spinning on the 573194317Sattilio * interlock itself. 574194317Sattilio */ 575194317Sattilio if (flags & LK_INTERLOCK) { 576194317Sattilio class->lc_unlock(ilk); 577194317Sattilio flags &= ~LK_INTERLOCK; 578194317Sattilio } 579194317Sattilio GIANT_SAVE(); 580194317Sattilio while (LK_HOLDER(lk->lk_lock) == 581194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 582194317Sattilio cpu_spinwait(); 583196772Sattilio GIANT_RESTORE(); 584196772Sattilio continue; 585194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 586196772Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 587194317Sattilio spintries < alk_retries) { 588194317Sattilio if (flags & LK_INTERLOCK) { 589194317Sattilio class->lc_unlock(ilk); 590194317Sattilio flags &= ~LK_INTERLOCK; 591194317Sattilio } 592194317Sattilio GIANT_SAVE(); 593194317Sattilio spintries++; 594194317Sattilio for (i = 0; i < alk_loops; i++) { 595194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 596194317Sattilio CTR4(KTR_LOCK, 597194317Sattilio "%s: shared spinning on %p with %u and %u", 598194317Sattilio __func__, lk, spintries, i); 599194317Sattilio x = lk->lk_lock; 600194317Sattilio if ((x & LK_SHARE) == 0 || 601194317Sattilio LK_CAN_SHARE(x) != 0) 602194317Sattilio break; 603194317Sattilio cpu_spinwait(); 604194317Sattilio } 605196772Sattilio GIANT_RESTORE(); 606194317Sattilio if (i != alk_loops) 607194317Sattilio continue; 608194317Sattilio } 609194317Sattilio#endif 610194317Sattilio 611194317Sattilio /* 612177957Sattilio * Acquire the sleepqueue chain lock because we 613177957Sattilio * probabilly will need to manipulate waiters flags. 614177957Sattilio */ 615177957Sattilio sleepq_lock(&lk->lock_object); 616177957Sattilio x = lk->lk_lock; 617111463Sjeff 618177957Sattilio /* 619177957Sattilio * if the lock can be acquired in shared mode, try 620177957Sattilio * again. 621177957Sattilio */ 622177957Sattilio if (LK_CAN_SHARE(x)) { 623177957Sattilio sleepq_release(&lk->lock_object); 624177957Sattilio continue; 625177957Sattilio } 62624269Speter 627194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 628177957Sattilio /* 629194317Sattilio * The current lock owner might have started executing 630194317Sattilio * on another CPU (or the lock could have changed 631194317Sattilio * owner) while we were waiting on the turnstile 632194317Sattilio * chain lock. If so, drop the turnstile lock and try 633194317Sattilio * again. 634194317Sattilio */ 635194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 636194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 637194317Sattilio owner = (struct thread *)LK_HOLDER(x); 638194317Sattilio if (TD_IS_RUNNING(owner)) { 639194317Sattilio sleepq_release(&lk->lock_object); 640194317Sattilio continue; 641194317Sattilio } 642194317Sattilio } 643194317Sattilio#endif 644194317Sattilio 645194317Sattilio /* 646177957Sattilio * Try to set the LK_SHARED_WAITERS flag. If we fail, 647177957Sattilio * loop back and retry. 648177957Sattilio */ 649177957Sattilio if ((x & LK_SHARED_WAITERS) == 0) { 650177957Sattilio if (!atomic_cmpset_acq_ptr(&lk->lk_lock, x, 651177957Sattilio x | LK_SHARED_WAITERS)) { 652177957Sattilio sleepq_release(&lk->lock_object); 653177957Sattilio continue; 654177957Sattilio } 655177957Sattilio LOCK_LOG2(lk, "%s: %p set shared waiters flag", 656177957Sattilio __func__, lk); 657177957Sattilio } 65824269Speter 659177957Sattilio /* 660177957Sattilio * As far as we have been unable to acquire the 661177957Sattilio * shared lock and the shared waiters flag is set, 662177957Sattilio * we will sleep. 663177957Sattilio */ 664177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 665177957Sattilio SQ_SHARED_QUEUE); 666177957Sattilio flags &= ~LK_INTERLOCK; 667177957Sattilio if (error) { 668177957Sattilio LOCK_LOG3(lk, 669177957Sattilio "%s: interrupted sleep for %p with %d", 670177957Sattilio __func__, lk, error); 671177957Sattilio break; 672177957Sattilio } 673177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 674177957Sattilio __func__, lk); 675177957Sattilio } 676177957Sattilio if (error == 0) { 677177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 678177957Sattilio contested, waittime, file, line); 679177957Sattilio LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, file, 680176014Sattilio line); 681178159Sattilio WITNESS_LOCK(&lk->lock_object, LK_TRYWIT(flags), file, 682178159Sattilio line); 683177957Sattilio TD_LOCKS_INC(curthread); 684177957Sattilio TD_SLOCKS_INC(curthread); 685177957Sattilio STACK_SAVE(lk); 686177957Sattilio } 687177957Sattilio break; 688177957Sattilio case LK_UPGRADE: 689177957Sattilio _lockmgr_assert(lk, KA_SLOCKED, file, line); 690194317Sattilio v = lk->lk_lock; 691194317Sattilio x = v & LK_ALL_WAITERS; 692194317Sattilio v &= LK_EXCLUSIVE_SPINNERS; 693177957Sattilio 69444681Sjulian /* 695177957Sattilio * Try to switch from one shared lock to an exclusive one. 696177957Sattilio * We need to preserve waiters flags during the operation. 69744681Sjulian */ 698194317Sattilio if (atomic_cmpset_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x | v, 699177957Sattilio tid | x)) { 700177957Sattilio LOCK_LOG_LOCK("XUPGRADE", &lk->lock_object, 0, 0, file, 701177957Sattilio line); 702178159Sattilio WITNESS_UPGRADE(&lk->lock_object, LOP_EXCLUSIVE | 703178159Sattilio LK_TRYWIT(flags), file, line); 704177957Sattilio TD_SLOCKS_DEC(curthread); 70524269Speter break; 70624269Speter } 707177957Sattilio 70824269Speter /* 709177957Sattilio * We have been unable to succeed in upgrading, so just 710177957Sattilio * give up the shared lock. 71124269Speter */ 712182010Sjhb wakeup_swapper |= wakeupshlk(lk, file, line); 71324269Speter 714177957Sattilio /* FALLTHROUGH */ 715177957Sattilio case LK_EXCLUSIVE: 716178159Sattilio if (LK_CAN_WITNESS(flags)) 717178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 718182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 71924269Speter 72024269Speter /* 721180798Skib * If curthread already holds the lock and this one is 722177957Sattilio * allowed to recurse, simply recurse on it. 72324269Speter */ 724177957Sattilio if (lockmgr_xlocked(lk)) { 725177957Sattilio if ((flags & LK_CANRECURSE) == 0 && 726193307Sattilio (lk->lock_object.lo_flags & LO_RECURSABLE) == 0) { 727177957Sattilio 728177957Sattilio /* 729177957Sattilio * If the lock is expected to not panic just 730177957Sattilio * give up and return. 731177957Sattilio */ 732177957Sattilio if (LK_TRYOP(flags)) { 733177957Sattilio LOCK_LOG2(lk, 734177957Sattilio "%s: %p fails the try operation", 735177957Sattilio __func__, lk); 736177957Sattilio error = EBUSY; 737177957Sattilio break; 738177957Sattilio } 739177957Sattilio if (flags & LK_INTERLOCK) 740177957Sattilio class->lc_unlock(ilk); 741177957Sattilio panic("%s: recursing on non recursive lockmgr %s @ %s:%d\n", 742177957Sattilio __func__, iwmesg, file, line); 743177957Sattilio } 744177957Sattilio lk->lk_recurse++; 745177957Sattilio LOCK_LOG2(lk, "%s: %p recursing", __func__, lk); 746177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 747177957Sattilio lk->lk_recurse, file, line); 748178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 749178159Sattilio LK_TRYWIT(flags), file, line); 750177957Sattilio TD_LOCKS_INC(curthread); 75124269Speter break; 75224269Speter } 753177957Sattilio 754177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, 755177957Sattilio tid)) { 756233628Sfabient#ifdef HWPMC_HOOKS 757233628Sfabient PMC_SOFT_CALL( , , lock, failed); 758233628Sfabient#endif 759177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 760177957Sattilio &contested, &waittime); 761177957Sattilio 76224269Speter /* 763177957Sattilio * If the lock is expected to not sleep just give up 764177957Sattilio * and return. 76524269Speter */ 766177957Sattilio if (LK_TRYOP(flags)) { 767177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 768177957Sattilio __func__, lk); 769177957Sattilio error = EBUSY; 770177957Sattilio break; 771177957Sattilio } 77234194Sdyson 773194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 774177957Sattilio /* 775194317Sattilio * If the owner is running on another CPU, spin until 776194317Sattilio * the owner stops running or the state of the lock 777194317Sattilio * changes. 778194317Sattilio */ 779194317Sattilio x = lk->lk_lock; 780194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 781194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 782194317Sattilio owner = (struct thread *)LK_HOLDER(x); 783194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 784194317Sattilio CTR3(KTR_LOCK, 785194317Sattilio "%s: spinning on %p held by %p", 786194317Sattilio __func__, lk, owner); 787194317Sattilio 788194317Sattilio /* 789194317Sattilio * If we are holding also an interlock drop it 790194317Sattilio * in order to avoid a deadlock if the lockmgr 791194317Sattilio * owner is adaptively spinning on the 792194317Sattilio * interlock itself. 793194317Sattilio */ 794194317Sattilio if (flags & LK_INTERLOCK) { 795194317Sattilio class->lc_unlock(ilk); 796194317Sattilio flags &= ~LK_INTERLOCK; 797194317Sattilio } 798194317Sattilio GIANT_SAVE(); 799194317Sattilio while (LK_HOLDER(lk->lk_lock) == 800194317Sattilio (uintptr_t)owner && TD_IS_RUNNING(owner)) 801194317Sattilio cpu_spinwait(); 802196772Sattilio GIANT_RESTORE(); 803196772Sattilio continue; 804194317Sattilio } else if (LK_CAN_ADAPT(lk, flags) && 805194317Sattilio (x & LK_SHARE) != 0 && LK_SHARERS(x) && 806194317Sattilio spintries < alk_retries) { 807194317Sattilio if ((x & LK_EXCLUSIVE_SPINNERS) == 0 && 808194317Sattilio !atomic_cmpset_ptr(&lk->lk_lock, x, 809194317Sattilio x | LK_EXCLUSIVE_SPINNERS)) 810194317Sattilio continue; 811194317Sattilio if (flags & LK_INTERLOCK) { 812194317Sattilio class->lc_unlock(ilk); 813194317Sattilio flags &= ~LK_INTERLOCK; 814194317Sattilio } 815194317Sattilio GIANT_SAVE(); 816194317Sattilio spintries++; 817194317Sattilio for (i = 0; i < alk_loops; i++) { 818194317Sattilio if (LOCK_LOG_TEST(&lk->lock_object, 0)) 819194317Sattilio CTR4(KTR_LOCK, 820194317Sattilio "%s: shared spinning on %p with %u and %u", 821194317Sattilio __func__, lk, spintries, i); 822194317Sattilio if ((lk->lk_lock & 823194317Sattilio LK_EXCLUSIVE_SPINNERS) == 0) 824194317Sattilio break; 825194317Sattilio cpu_spinwait(); 826194317Sattilio } 827196772Sattilio GIANT_RESTORE(); 828194317Sattilio if (i != alk_loops) 829194317Sattilio continue; 830194317Sattilio } 831194317Sattilio#endif 832194317Sattilio 833194317Sattilio /* 834177957Sattilio * Acquire the sleepqueue chain lock because we 835177957Sattilio * probabilly will need to manipulate waiters flags. 836177957Sattilio */ 837177957Sattilio sleepq_lock(&lk->lock_object); 838177957Sattilio x = lk->lk_lock; 839177957Sattilio 840177957Sattilio /* 841177957Sattilio * if the lock has been released while we spun on 842177957Sattilio * the sleepqueue chain lock just try again. 843177957Sattilio */ 844177957Sattilio if (x == LK_UNLOCKED) { 845177957Sattilio sleepq_release(&lk->lock_object); 846177957Sattilio continue; 847134365Skan } 84824269Speter 849194317Sattilio#ifdef ADAPTIVE_LOCKMGRS 85024269Speter /* 851194317Sattilio * The current lock owner might have started executing 852194317Sattilio * on another CPU (or the lock could have changed 853194317Sattilio * owner) while we were waiting on the turnstile 854194317Sattilio * chain lock. If so, drop the turnstile lock and try 855194317Sattilio * again. 856194317Sattilio */ 857194317Sattilio if (LK_CAN_ADAPT(lk, flags) && (x & LK_SHARE) == 0 && 858194317Sattilio LK_HOLDER(x) != LK_KERNPROC) { 859194317Sattilio owner = (struct thread *)LK_HOLDER(x); 860194317Sattilio if (TD_IS_RUNNING(owner)) { 861194317Sattilio sleepq_release(&lk->lock_object); 862194317Sattilio continue; 863194317Sattilio } 864194317Sattilio } 865194317Sattilio#endif 866194317Sattilio 867194317Sattilio /* 868177957Sattilio * The lock can be in the state where there is a 869177957Sattilio * pending queue of waiters, but still no owner. 870177957Sattilio * This happens when the lock is contested and an 871177957Sattilio * owner is going to claim the lock. 872177957Sattilio * If curthread is the one successfully acquiring it 873177957Sattilio * claim lock ownership and return, preserving waiters 874177957Sattilio * flags. 87524269Speter */ 876194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 877194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 878194317Sattilio v &= ~LK_EXCLUSIVE_SPINNERS; 879177957Sattilio if (atomic_cmpset_acq_ptr(&lk->lk_lock, x, 880177957Sattilio tid | v)) { 881177957Sattilio sleepq_release(&lk->lock_object); 882177957Sattilio LOCK_LOG2(lk, 883177957Sattilio "%s: %p claimed by a new writer", 884177957Sattilio __func__, lk); 885177957Sattilio break; 886177957Sattilio } 887177957Sattilio sleepq_release(&lk->lock_object); 888177957Sattilio continue; 889177957Sattilio } 890177957Sattilio 891177957Sattilio /* 892177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 893177957Sattilio * fail, loop back and retry. 894177957Sattilio */ 895177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 896177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 897177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 898177957Sattilio sleepq_release(&lk->lock_object); 899177957Sattilio continue; 900177957Sattilio } 901177957Sattilio LOCK_LOG2(lk, "%s: %p set excl waiters flag", 902177957Sattilio __func__, lk); 903177957Sattilio } 904177957Sattilio 905177957Sattilio /* 906177957Sattilio * As far as we have been unable to acquire the 907177957Sattilio * exclusive lock and the exclusive waiters flag 908177957Sattilio * is set, we will sleep. 909177957Sattilio */ 910177957Sattilio error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo, 911177957Sattilio SQ_EXCLUSIVE_QUEUE); 912177957Sattilio flags &= ~LK_INTERLOCK; 913177957Sattilio if (error) { 914177957Sattilio LOCK_LOG3(lk, 915177957Sattilio "%s: interrupted sleep for %p with %d", 916177957Sattilio __func__, lk, error); 91748301Smckusick break; 91848301Smckusick } 919177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 920177957Sattilio __func__, lk); 92124269Speter } 922177957Sattilio if (error == 0) { 923177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 924177957Sattilio contested, waittime, file, line); 925177957Sattilio LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, 926177957Sattilio lk->lk_recurse, file, line); 927178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 928178159Sattilio LK_TRYWIT(flags), file, line); 929177957Sattilio TD_LOCKS_INC(curthread); 930177957Sattilio STACK_SAVE(lk); 931177957Sattilio } 932177957Sattilio break; 933177957Sattilio case LK_DOWNGRADE: 934177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 935178159Sattilio LOCK_LOG_LOCK("XDOWNGRADE", &lk->lock_object, 0, 0, file, line); 936178159Sattilio WITNESS_DOWNGRADE(&lk->lock_object, 0, file, line); 937178159Sattilio TD_SLOCKS_INC(curthread); 938177957Sattilio 93924269Speter /* 940177957Sattilio * In order to preserve waiters flags, just spin. 94124269Speter */ 942177957Sattilio for (;;) { 943194317Sattilio x = lk->lk_lock; 944194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 945194317Sattilio x &= LK_ALL_WAITERS; 946177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 947178159Sattilio LK_SHARERS_LOCK(1) | x)) 948177957Sattilio break; 949177957Sattilio cpu_spinwait(); 95024269Speter } 95124269Speter break; 952177957Sattilio case LK_RELEASE: 953177957Sattilio _lockmgr_assert(lk, KA_LOCKED, file, line); 954177957Sattilio x = lk->lk_lock; 95524269Speter 956177957Sattilio if ((x & LK_SHARE) == 0) { 957177957Sattilio 958177957Sattilio /* 959177957Sattilio * As first option, treact the lock as if it has not 960177957Sattilio * any waiter. 961177957Sattilio * Fix-up the tid var if the lock has been disowned. 962177957Sattilio */ 963177957Sattilio if (LK_HOLDER(x) == LK_KERNPROC) 964177957Sattilio tid = LK_KERNPROC; 965178159Sattilio else { 966178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, 967178159Sattilio file, line); 968177957Sattilio TD_LOCKS_DEC(curthread); 969178159Sattilio } 970177957Sattilio LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, 971177957Sattilio lk->lk_recurse, file, line); 972177957Sattilio 973177957Sattilio /* 974177957Sattilio * The lock is held in exclusive mode. 975177957Sattilio * If the lock is recursed also, then unrecurse it. 976177957Sattilio */ 977177957Sattilio if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) { 978177957Sattilio LOCK_LOG2(lk, "%s: %p unrecursing", __func__, 979177957Sattilio lk); 980177957Sattilio lk->lk_recurse--; 981177957Sattilio break; 982176014Sattilio } 983189788Sjeff if (tid != LK_KERNPROC) 984189788Sjeff lock_profile_release_lock(&lk->lock_object); 985177957Sattilio 986177957Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid, 987177957Sattilio LK_UNLOCKED)) 988177957Sattilio break; 989177957Sattilio 990177957Sattilio sleepq_lock(&lk->lock_object); 991194317Sattilio x = lk->lk_lock; 992177957Sattilio v = LK_UNLOCKED; 993177957Sattilio 994177957Sattilio /* 995177957Sattilio * If the lock has exclusive waiters, give them 996177957Sattilio * preference in order to avoid deadlock with 997177957Sattilio * shared runners up. 998200447Sattilio * If interruptible sleeps left the exclusive queue 999200447Sattilio * empty avoid a starvation for the threads sleeping 1000200447Sattilio * on the shared queue by giving them precedence 1001200447Sattilio * and cleaning up the exclusive waiters bit anyway. 1002201709Sattilio * Please note that lk_exslpfail count may be lying 1003201709Sattilio * about the real number of waiters with the 1004201709Sattilio * LK_SLEEPFAIL flag on because they may be used in 1005201709Sattilio * conjuction with interruptible sleeps so 1006201710Sattilio * lk_exslpfail might be considered an 'upper limit' 1007201710Sattilio * bound, including the edge cases. 1008177957Sattilio */ 1009194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1010200447Sattilio realexslp = sleepq_sleepcnt(&lk->lock_object, 1011200447Sattilio SQ_EXCLUSIVE_QUEUE); 1012200447Sattilio if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) { 1013200447Sattilio if (lk->lk_exslpfail < realexslp) { 1014200447Sattilio lk->lk_exslpfail = 0; 1015200447Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1016200447Sattilio v |= (x & LK_SHARED_WAITERS); 1017200447Sattilio } else { 1018200447Sattilio lk->lk_exslpfail = 0; 1019200447Sattilio LOCK_LOG2(lk, 1020200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1021200447Sattilio __func__, lk); 1022200447Sattilio LOCK_LOG2(lk, 1023200447Sattilio "%s: %p waking up threads on the exclusive queue", 1024200447Sattilio __func__, lk); 1025200447Sattilio wakeup_swapper = 1026200447Sattilio sleepq_broadcast(&lk->lock_object, 1027200447Sattilio SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE); 1028200447Sattilio queue = SQ_SHARED_QUEUE; 1029200447Sattilio } 1030177957Sattilio } else { 1031201703Sattilio 1032201703Sattilio /* 1033201703Sattilio * Exclusive waiters sleeping with LK_SLEEPFAIL 1034201703Sattilio * on and using interruptible sleeps/timeout 1035201703Sattilio * may have left spourious lk_exslpfail counts 1036201703Sattilio * on, so clean it up anyway. 1037201703Sattilio */ 1038201703Sattilio lk->lk_exslpfail = 0; 1039177957Sattilio queue = SQ_SHARED_QUEUE; 104024269Speter } 1041149723Sssouhlal 1042177957Sattilio LOCK_LOG3(lk, 1043177957Sattilio "%s: %p waking up threads on the %s queue", 1044177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" : 1045177957Sattilio "exclusive"); 1046177957Sattilio atomic_store_rel_ptr(&lk->lk_lock, v); 1047200447Sattilio wakeup_swapper |= sleepq_broadcast(&lk->lock_object, 1048181334Sjhb SLEEPQ_LK, 0, queue); 1049177957Sattilio sleepq_release(&lk->lock_object); 1050177957Sattilio break; 1051177957Sattilio } else 1052181334Sjhb wakeup_swapper = wakeupshlk(lk, file, line); 105324269Speter break; 1054177957Sattilio case LK_DRAIN: 1055178159Sattilio if (LK_CAN_WITNESS(flags)) 1056178159Sattilio WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER | 1057182914Sjhb LOP_EXCLUSIVE, file, line, ilk); 105824269Speter 105924269Speter /* 1060180798Skib * Trying to drain a lock we already own will result in a 1061177957Sattilio * deadlock. 106224269Speter */ 1063177957Sattilio if (lockmgr_xlocked(lk)) { 1064177957Sattilio if (flags & LK_INTERLOCK) 1065177957Sattilio class->lc_unlock(ilk); 1066177957Sattilio panic("%s: draining %s with the lock held @ %s:%d\n", 1067177957Sattilio __func__, iwmesg, file, line); 1068177957Sattilio } 106928345Sdyson 1070177957Sattilio while (!atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) { 1071233628Sfabient#ifdef HWPMC_HOOKS 1072233628Sfabient PMC_SOFT_CALL( , , lock, failed); 1073233628Sfabient#endif 1074177957Sattilio lock_profile_obtain_lock_failed(&lk->lock_object, 1075177957Sattilio &contested, &waittime); 107624269Speter 1077177957Sattilio /* 1078177957Sattilio * If the lock is expected to not sleep just give up 1079177957Sattilio * and return. 1080177957Sattilio */ 1081177957Sattilio if (LK_TRYOP(flags)) { 1082177957Sattilio LOCK_LOG2(lk, "%s: %p fails the try operation", 1083177957Sattilio __func__, lk); 1084177957Sattilio error = EBUSY; 1085177957Sattilio break; 1086177957Sattilio } 108724269Speter 1088177957Sattilio /* 1089177957Sattilio * Acquire the sleepqueue chain lock because we 1090177957Sattilio * probabilly will need to manipulate waiters flags. 1091177957Sattilio */ 1092177957Sattilio sleepq_lock(&lk->lock_object); 1093177957Sattilio x = lk->lk_lock; 109429653Sdyson 1095177957Sattilio /* 1096177957Sattilio * if the lock has been released while we spun on 1097177957Sattilio * the sleepqueue chain lock just try again. 1098177957Sattilio */ 1099177957Sattilio if (x == LK_UNLOCKED) { 1100177957Sattilio sleepq_release(&lk->lock_object); 1101177957Sattilio continue; 1102177957Sattilio } 1103176320Sattilio 1104194317Sattilio v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS); 1105194317Sattilio if ((x & ~v) == LK_UNLOCKED) { 1106194317Sattilio v = (x & ~LK_EXCLUSIVE_SPINNERS); 1107200447Sattilio 1108200447Sattilio /* 1109200447Sattilio * If interruptible sleeps left the exclusive 1110200447Sattilio * queue empty avoid a starvation for the 1111200447Sattilio * threads sleeping on the shared queue by 1112200447Sattilio * giving them precedence and cleaning up the 1113200447Sattilio * exclusive waiters bit anyway. 1114201709Sattilio * Please note that lk_exslpfail count may be 1115201709Sattilio * lying about the real number of waiters with 1116201709Sattilio * the LK_SLEEPFAIL flag on because they may 1117201709Sattilio * be used in conjuction with interruptible 1118201710Sattilio * sleeps so lk_exslpfail might be considered 1119201710Sattilio * an 'upper limit' bound, including the edge 1120201709Sattilio * cases. 1121200447Sattilio */ 1122177957Sattilio if (v & LK_EXCLUSIVE_WAITERS) { 1123177957Sattilio queue = SQ_EXCLUSIVE_QUEUE; 1124177957Sattilio v &= ~LK_EXCLUSIVE_WAITERS; 1125177957Sattilio } else { 1126201703Sattilio 1127201703Sattilio /* 1128201703Sattilio * Exclusive waiters sleeping with 1129201703Sattilio * LK_SLEEPFAIL on and using 1130201703Sattilio * interruptible sleeps/timeout may 1131201703Sattilio * have left spourious lk_exslpfail 1132201703Sattilio * counts on, so clean it up anyway. 1133201703Sattilio */ 1134177957Sattilio MPASS(v & LK_SHARED_WAITERS); 1135201703Sattilio lk->lk_exslpfail = 0; 1136177957Sattilio queue = SQ_SHARED_QUEUE; 1137177957Sattilio v &= ~LK_SHARED_WAITERS; 1138177957Sattilio } 1139200447Sattilio if (queue == SQ_EXCLUSIVE_QUEUE) { 1140200447Sattilio realexslp = 1141200447Sattilio sleepq_sleepcnt(&lk->lock_object, 1142200447Sattilio SQ_EXCLUSIVE_QUEUE); 1143200447Sattilio if (lk->lk_exslpfail >= realexslp) { 1144200447Sattilio lk->lk_exslpfail = 0; 1145200447Sattilio queue = SQ_SHARED_QUEUE; 1146200447Sattilio v &= ~LK_SHARED_WAITERS; 1147200447Sattilio if (realexslp != 0) { 1148200447Sattilio LOCK_LOG2(lk, 1149200447Sattilio "%s: %p has only LK_SLEEPFAIL sleepers", 1150200447Sattilio __func__, lk); 1151200447Sattilio LOCK_LOG2(lk, 1152200447Sattilio "%s: %p waking up threads on the exclusive queue", 1153200447Sattilio __func__, lk); 1154200447Sattilio wakeup_swapper = 1155200447Sattilio sleepq_broadcast( 1156200447Sattilio &lk->lock_object, 1157200447Sattilio SLEEPQ_LK, 0, 1158200447Sattilio SQ_EXCLUSIVE_QUEUE); 1159200447Sattilio } 1160200447Sattilio } else 1161200447Sattilio lk->lk_exslpfail = 0; 1162200447Sattilio } 1163177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, v)) { 1164177957Sattilio sleepq_release(&lk->lock_object); 1165177957Sattilio continue; 1166177957Sattilio } 1167177957Sattilio LOCK_LOG3(lk, 1168177957Sattilio "%s: %p waking up all threads on the %s queue", 1169177957Sattilio __func__, lk, queue == SQ_SHARED_QUEUE ? 1170177957Sattilio "shared" : "exclusive"); 1171182010Sjhb wakeup_swapper |= sleepq_broadcast( 1172181334Sjhb &lk->lock_object, SLEEPQ_LK, 0, queue); 1173177957Sattilio 1174177957Sattilio /* 1175177957Sattilio * If shared waiters have been woken up we need 1176177957Sattilio * to wait for one of them to acquire the lock 1177177957Sattilio * before to set the exclusive waiters in 1178177957Sattilio * order to avoid a deadlock. 1179177957Sattilio */ 1180177957Sattilio if (queue == SQ_SHARED_QUEUE) { 1181177957Sattilio for (v = lk->lk_lock; 1182177957Sattilio (v & LK_SHARE) && !LK_SHARERS(v); 1183177957Sattilio v = lk->lk_lock) 1184177957Sattilio cpu_spinwait(); 1185177957Sattilio } 1186177957Sattilio } 1187177957Sattilio 1188177957Sattilio /* 1189177957Sattilio * Try to set the LK_EXCLUSIVE_WAITERS flag. If we 1190177957Sattilio * fail, loop back and retry. 1191177957Sattilio */ 1192177957Sattilio if ((x & LK_EXCLUSIVE_WAITERS) == 0) { 1193177957Sattilio if (!atomic_cmpset_ptr(&lk->lk_lock, x, 1194177957Sattilio x | LK_EXCLUSIVE_WAITERS)) { 1195177957Sattilio sleepq_release(&lk->lock_object); 1196177957Sattilio continue; 1197177957Sattilio } 1198177957Sattilio LOCK_LOG2(lk, "%s: %p set drain waiters flag", 1199177957Sattilio __func__, lk); 1200177957Sattilio } 1201177957Sattilio 1202177957Sattilio /* 1203177957Sattilio * As far as we have been unable to acquire the 1204177957Sattilio * exclusive lock and the exclusive waiters flag 1205177957Sattilio * is set, we will sleep. 1206177957Sattilio */ 1207177957Sattilio if (flags & LK_INTERLOCK) { 1208177957Sattilio class->lc_unlock(ilk); 1209177957Sattilio flags &= ~LK_INTERLOCK; 1210177957Sattilio } 1211178159Sattilio GIANT_SAVE(); 1212177957Sattilio sleepq_add(&lk->lock_object, NULL, iwmesg, SLEEPQ_LK, 1213177957Sattilio SQ_EXCLUSIVE_QUEUE); 1214177957Sattilio sleepq_wait(&lk->lock_object, ipri & PRIMASK); 1215178159Sattilio GIANT_RESTORE(); 1216177957Sattilio LOCK_LOG2(lk, "%s: %p resuming from the sleep queue", 1217177957Sattilio __func__, lk); 121829653Sdyson } 1219177957Sattilio 1220177957Sattilio if (error == 0) { 1221177957Sattilio lock_profile_obtain_lock_success(&lk->lock_object, 1222177957Sattilio contested, waittime, file, line); 1223177957Sattilio LOCK_LOG_LOCK("DRAIN", &lk->lock_object, 0, 1224177957Sattilio lk->lk_recurse, file, line); 1225178159Sattilio WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | 1226178159Sattilio LK_TRYWIT(flags), file, line); 1227177957Sattilio TD_LOCKS_INC(curthread); 1228177957Sattilio STACK_SAVE(lk); 1229177957Sattilio } 1230177957Sattilio break; 1231177957Sattilio default: 1232177957Sattilio if (flags & LK_INTERLOCK) 1233177957Sattilio class->lc_unlock(ilk); 1234177957Sattilio panic("%s: unknown lockmgr request 0x%x\n", __func__, op); 123529653Sdyson } 1236177957Sattilio 1237177957Sattilio if (flags & LK_INTERLOCK) 1238177957Sattilio class->lc_unlock(ilk); 1239181334Sjhb if (wakeup_swapper) 1240181334Sjhb kick_proc0(); 1241177957Sattilio 1242177957Sattilio return (error); 124329653Sdyson} 124429653Sdyson 124529653Sdysonvoid 1246177957Sattilio_lockmgr_disown(struct lock *lk, const char *file, int line) 124729653Sdyson{ 1248177957Sattilio uintptr_t tid, x; 1249176014Sattilio 1250228424Savg if (SCHEDULER_STOPPED()) 1251228424Savg return; 1252228424Savg 1253177957Sattilio tid = (uintptr_t)curthread; 1254177957Sattilio _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED, file, line); 125529653Sdyson 1256177957Sattilio /* 1257180798Skib * If the owner is already LK_KERNPROC just skip the whole operation. 1258177957Sattilio */ 1259177957Sattilio if (LK_HOLDER(lk->lk_lock) != tid) 1260177957Sattilio return; 1261189788Sjeff lock_profile_release_lock(&lk->lock_object); 1262178159Sattilio LOCK_LOG_LOCK("XDISOWN", &lk->lock_object, 0, 0, file, line); 1263178159Sattilio WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line); 1264178159Sattilio TD_LOCKS_DEC(curthread); 1265199008Sattilio STACK_SAVE(lk); 126629653Sdyson 1267177957Sattilio /* 1268177957Sattilio * In order to preserve waiters flags, just spin. 1269177957Sattilio */ 1270177957Sattilio for (;;) { 1271194317Sattilio x = lk->lk_lock; 1272194317Sattilio MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0); 1273194317Sattilio x &= LK_ALL_WAITERS; 1274178166Sattilio if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x, 1275178159Sattilio LK_KERNPROC | x)) 1276177957Sattilio return; 1277177957Sattilio cpu_spinwait(); 1278177957Sattilio } 127966615Sjasone} 128066615Sjasone 1281175166Sattiliovoid 1282227588Spjdlockmgr_printinfo(const struct lock *lk) 1283175166Sattilio{ 1284175166Sattilio struct thread *td; 1285177957Sattilio uintptr_t x; 1286175166Sattilio 1287177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1288188244Sjhb printf("lock type %s: UNLOCKED\n", lk->lock_object.lo_name); 1289177957Sattilio else if (lk->lk_lock & LK_SHARE) 1290188244Sjhb printf("lock type %s: SHARED (count %ju)\n", 1291177957Sattilio lk->lock_object.lo_name, 1292177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1293177957Sattilio else { 1294177957Sattilio td = lockmgr_xholder(lk); 1295232547Sivoras printf("lock type %s: EXCL by thread %p " 1296232547Sivoras "(pid %d, %s, tid %d)\n", lk->lock_object.lo_name, td, 1297232547Sivoras td->td_proc->p_pid, td->td_proc->p_comm, td->td_tid); 1298177957Sattilio } 1299175166Sattilio 1300177957Sattilio x = lk->lk_lock; 1301177957Sattilio if (x & LK_EXCLUSIVE_WAITERS) 1302177957Sattilio printf(" with exclusive waiters pending\n"); 1303177957Sattilio if (x & LK_SHARED_WAITERS) 1304177957Sattilio printf(" with shared waiters pending\n"); 1305194317Sattilio if (x & LK_EXCLUSIVE_SPINNERS) 1306194317Sattilio printf(" with exclusive spinners pending\n"); 1307177957Sattilio 1308177957Sattilio STACK_PRINT(lk); 1309175166Sattilio} 1310175166Sattilio 131129653Sdysonint 1312227588Spjdlockstatus(const struct lock *lk) 131329653Sdyson{ 1314177957Sattilio uintptr_t v, x; 1315177957Sattilio int ret; 131629653Sdyson 1317177957Sattilio ret = LK_SHARED; 1318177957Sattilio x = lk->lk_lock; 1319177957Sattilio v = LK_HOLDER(x); 1320175635Sattilio 1321177957Sattilio if ((x & LK_SHARE) == 0) { 1322177957Sattilio if (v == (uintptr_t)curthread || v == LK_KERNPROC) 1323177957Sattilio ret = LK_EXCLUSIVE; 132454444Seivind else 1325177957Sattilio ret = LK_EXCLOTHER; 1326177957Sattilio } else if (x == LK_UNLOCKED) 1327177957Sattilio ret = 0; 132829653Sdyson 1329177957Sattilio return (ret); 133024269Speter} 1331161322Sjhb 1332176249Sattilio#ifdef INVARIANT_SUPPORT 1333219028Snetchild 1334219028SnetchildFEATURE(invariant_support, 1335219028Snetchild "Support for modules compiled with INVARIANTS option"); 1336219028Snetchild 1337176249Sattilio#ifndef INVARIANTS 1338177957Sattilio#undef _lockmgr_assert 1339176249Sattilio#endif 1340176249Sattilio 1341176249Sattiliovoid 1342227588Spjd_lockmgr_assert(const struct lock *lk, int what, const char *file, int line) 1343176249Sattilio{ 1344176249Sattilio int slocked = 0; 1345176249Sattilio 1346176249Sattilio if (panicstr != NULL) 1347176249Sattilio return; 1348176249Sattilio switch (what) { 1349176249Sattilio case KA_SLOCKED: 1350176249Sattilio case KA_SLOCKED | KA_NOTRECURSED: 1351176249Sattilio case KA_SLOCKED | KA_RECURSED: 1352176249Sattilio slocked = 1; 1353176249Sattilio case KA_LOCKED: 1354176249Sattilio case KA_LOCKED | KA_NOTRECURSED: 1355176249Sattilio case KA_LOCKED | KA_RECURSED: 1356178159Sattilio#ifdef WITNESS 1357178159Sattilio 1358178159Sattilio /* 1359178159Sattilio * We cannot trust WITNESS if the lock is held in exclusive 1360178159Sattilio * mode and a call to lockmgr_disown() happened. 1361178159Sattilio * Workaround this skipping the check if the lock is held in 1362178159Sattilio * exclusive mode even for the KA_LOCKED case. 1363178159Sattilio */ 1364178159Sattilio if (slocked || (lk->lk_lock & LK_SHARE)) { 1365178159Sattilio witness_assert(&lk->lock_object, what, file, line); 1366178159Sattilio break; 1367178159Sattilio } 1368178159Sattilio#endif 1369177957Sattilio if (lk->lk_lock == LK_UNLOCKED || 1370177957Sattilio ((lk->lk_lock & LK_SHARE) == 0 && (slocked || 1371177957Sattilio (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk))))) 1372176249Sattilio panic("Lock %s not %slocked @ %s:%d\n", 1373177957Sattilio lk->lock_object.lo_name, slocked ? "share" : "", 1374176249Sattilio file, line); 1375177957Sattilio 1376177957Sattilio if ((lk->lk_lock & LK_SHARE) == 0) { 1377177957Sattilio if (lockmgr_recursed(lk)) { 1378176249Sattilio if (what & KA_NOTRECURSED) 1379176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1380177957Sattilio lk->lock_object.lo_name, file, 1381177957Sattilio line); 1382176249Sattilio } else if (what & KA_RECURSED) 1383176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1384177957Sattilio lk->lock_object.lo_name, file, line); 1385176249Sattilio } 1386176249Sattilio break; 1387176249Sattilio case KA_XLOCKED: 1388176249Sattilio case KA_XLOCKED | KA_NOTRECURSED: 1389176249Sattilio case KA_XLOCKED | KA_RECURSED: 1390177957Sattilio if (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk)) 1391176249Sattilio panic("Lock %s not exclusively locked @ %s:%d\n", 1392177957Sattilio lk->lock_object.lo_name, file, line); 1393177957Sattilio if (lockmgr_recursed(lk)) { 1394176249Sattilio if (what & KA_NOTRECURSED) 1395176249Sattilio panic("Lock %s recursed @ %s:%d\n", 1396177957Sattilio lk->lock_object.lo_name, file, line); 1397176249Sattilio } else if (what & KA_RECURSED) 1398176249Sattilio panic("Lock %s not recursed @ %s:%d\n", 1399177957Sattilio lk->lock_object.lo_name, file, line); 1400176249Sattilio break; 1401176249Sattilio case KA_UNLOCKED: 1402177957Sattilio if (lockmgr_xlocked(lk) || lockmgr_disowned(lk)) 1403176249Sattilio panic("Lock %s exclusively locked @ %s:%d\n", 1404177957Sattilio lk->lock_object.lo_name, file, line); 1405176249Sattilio break; 1406176249Sattilio default: 1407177957Sattilio panic("Unknown lockmgr assertion: %d @ %s:%d\n", what, file, 1408177957Sattilio line); 1409176249Sattilio } 1410176249Sattilio} 1411177957Sattilio#endif 1412176249Sattilio 1413161322Sjhb#ifdef DDB 1414161337Sjhbint 1415161337Sjhblockmgr_chain(struct thread *td, struct thread **ownerp) 1416161337Sjhb{ 1417177957Sattilio struct lock *lk; 1418161337Sjhb 1419177957Sattilio lk = td->td_wchan; 1420161337Sjhb 1421177957Sattilio if (LOCK_CLASS(&lk->lock_object) != &lock_class_lockmgr) 1422177957Sattilio return (0); 1423177957Sattilio db_printf("blocked on lockmgr %s", lk->lock_object.lo_name); 1424177957Sattilio if (lk->lk_lock & LK_SHARE) 1425177957Sattilio db_printf("SHARED (count %ju)\n", 1426177957Sattilio (uintmax_t)LK_SHARERS(lk->lk_lock)); 1427177957Sattilio else 1428177957Sattilio db_printf("EXCL\n"); 1429177957Sattilio *ownerp = lockmgr_xholder(lk); 1430161337Sjhb 1431161337Sjhb return (1); 1432161337Sjhb} 1433161337Sjhb 1434177957Sattiliostatic void 1435227588Spjddb_show_lockmgr(const struct lock_object *lock) 1436161322Sjhb{ 1437161322Sjhb struct thread *td; 1438227588Spjd const struct lock *lk; 1439161322Sjhb 1440227588Spjd lk = (const struct lock *)lock; 1441161322Sjhb 1442168070Sjhb db_printf(" state: "); 1443177957Sattilio if (lk->lk_lock == LK_UNLOCKED) 1444161322Sjhb db_printf("UNLOCKED\n"); 1445177957Sattilio else if (lk->lk_lock & LK_SHARE) 1446177957Sattilio db_printf("SLOCK: %ju\n", (uintmax_t)LK_SHARERS(lk->lk_lock)); 1447177957Sattilio else { 1448177957Sattilio td = lockmgr_xholder(lk); 1449177957Sattilio if (td == (struct thread *)LK_KERNPROC) 1450177957Sattilio db_printf("XLOCK: LK_KERNPROC\n"); 1451177957Sattilio else 1452177957Sattilio db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td, 1453177957Sattilio td->td_tid, td->td_proc->p_pid, 1454177957Sattilio td->td_proc->p_comm); 1455177957Sattilio if (lockmgr_recursed(lk)) 1456177957Sattilio db_printf(" recursed: %d\n", lk->lk_recurse); 1457177957Sattilio } 1458177957Sattilio db_printf(" waiters: "); 1459177957Sattilio switch (lk->lk_lock & LK_ALL_WAITERS) { 1460177957Sattilio case LK_SHARED_WAITERS: 1461177957Sattilio db_printf("shared\n"); 1462192022Strasz break; 1463177957Sattilio case LK_EXCLUSIVE_WAITERS: 1464177957Sattilio db_printf("exclusive\n"); 1465177957Sattilio break; 1466177957Sattilio case LK_ALL_WAITERS: 1467177957Sattilio db_printf("shared and exclusive\n"); 1468177957Sattilio break; 1469177957Sattilio default: 1470177957Sattilio db_printf("none\n"); 1471177957Sattilio } 1472194317Sattilio db_printf(" spinners: "); 1473194317Sattilio if (lk->lk_lock & LK_EXCLUSIVE_SPINNERS) 1474194317Sattilio db_printf("exclusive\n"); 1475194317Sattilio else 1476194317Sattilio db_printf("none\n"); 1477161322Sjhb} 1478161322Sjhb#endif 1479