2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice(s), this list of conditions and the following disclaimer as
12 * the first lines of this file unmodified other than the possible
13 * addition of one or more copyright notices.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice(s), this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
32 #include "opt_hwpmc_hooks.h"
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
37 #include <sys/param.h>
41 #include <sys/lock_profile.h>
42 #include <sys/lockmgr.h>
43 #include <sys/lockstat.h>
44 #include <sys/mutex.h>
46 #include <sys/sleepqueue.h>
48 #include <sys/stack.h>
50 #include <sys/sysctl.h>
51 #include <sys/systm.h>
53 #include <machine/cpu.h>
60 #include <sys/pmckern.h>
61 PMC_SOFT_DECLARE( , , lock, failed);
64 CTASSERT(LK_UNLOCKED == (LK_UNLOCKED &
65 ~(LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS)));
67 #define SQ_EXCLUSIVE_QUEUE 0
68 #define SQ_SHARED_QUEUE 1
71 #define _lockmgr_assert(lk, what, file, line)
74 #define TD_SLOCKS_INC(td) ((td)->td_lk_slocks++)
75 #define TD_SLOCKS_DEC(td) ((td)->td_lk_slocks--)
78 #define STACK_PRINT(lk)
79 #define STACK_SAVE(lk)
80 #define STACK_ZERO(lk)
82 #define STACK_PRINT(lk) stack_print_ddb(&(lk)->lk_stack)
83 #define STACK_SAVE(lk) stack_save(&(lk)->lk_stack)
84 #define STACK_ZERO(lk) stack_zero(&(lk)->lk_stack)
87 #define LOCK_LOG2(lk, string, arg1, arg2) \
88 if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \
89 CTR2(KTR_LOCK, (string), (arg1), (arg2))
90 #define LOCK_LOG3(lk, string, arg1, arg2, arg3) \
91 if (LOCK_LOG_TEST(&(lk)->lock_object, 0)) \
92 CTR3(KTR_LOCK, (string), (arg1), (arg2), (arg3))
94 #define GIANT_DECLARE \
96 WITNESS_SAVE_DECL(Giant)
97 #define GIANT_RESTORE() do { \
98 if (__predict_false(_i > 0)) { \
101 WITNESS_RESTORE(&Giant.lock_object, Giant); \
104 #define GIANT_SAVE() do { \
105 if (__predict_false(mtx_owned(&Giant))) { \
106 WITNESS_SAVE(&Giant.lock_object, Giant); \
107 while (mtx_owned(&Giant)) { \
109 mtx_unlock(&Giant); \
114 static bool __always_inline
115 LK_CAN_SHARE(uintptr_t x, int flags, bool fp)
118 if ((x & (LK_SHARE | LK_EXCLUSIVE_WAITERS | LK_EXCLUSIVE_SPINNERS)) ==
121 if (fp || (!(x & LK_SHARE)))
123 if ((curthread->td_lk_slocks != 0 && !(flags & LK_NODDLKTREAT)) ||
124 (curthread->td_pflags & TDP_DEADLKTREAT))
129 #define LK_TRYOP(x) \
132 #define LK_CAN_WITNESS(x) \
133 (((x) & LK_NOWITNESS) == 0 && !LK_TRYOP(x))
134 #define LK_TRYWIT(x) \
135 (LK_TRYOP(x) ? LOP_TRYLOCK : 0)
137 #define lockmgr_disowned(lk) \
138 (((lk)->lk_lock & ~(LK_FLAGMASK & ~LK_SHARE)) == LK_KERNPROC)
140 #define lockmgr_xlocked_v(v) \
141 (((v) & ~(LK_FLAGMASK & ~LK_SHARE)) == (uintptr_t)curthread)
143 #define lockmgr_xlocked(lk) lockmgr_xlocked_v((lk)->lk_lock)
145 static void assert_lockmgr(const struct lock_object *lock, int how);
147 static void db_show_lockmgr(const struct lock_object *lock);
149 static void lock_lockmgr(struct lock_object *lock, uintptr_t how);
151 static int owner_lockmgr(const struct lock_object *lock,
152 struct thread **owner);
154 static uintptr_t unlock_lockmgr(struct lock_object *lock);
156 struct lock_class lock_class_lockmgr = {
157 .lc_name = "lockmgr",
158 .lc_flags = LC_RECURSABLE | LC_SLEEPABLE | LC_SLEEPLOCK | LC_UPGRADABLE,
159 .lc_assert = assert_lockmgr,
161 .lc_ddb_show = db_show_lockmgr,
163 .lc_lock = lock_lockmgr,
164 .lc_unlock = unlock_lockmgr,
166 .lc_owner = owner_lockmgr,
170 struct lockmgr_wait {
176 static bool __always_inline lockmgr_slock_try(struct lock *lk, uintptr_t *xp,
178 static bool __always_inline lockmgr_sunlock_try(struct lock *lk, uintptr_t *xp);
181 lockmgr_exit(u_int flags, struct lock_object *ilk, int wakeup_swapper)
183 struct lock_class *class;
185 if (flags & LK_INTERLOCK) {
186 class = LOCK_CLASS(ilk);
187 class->lc_unlock(ilk);
190 if (__predict_false(wakeup_swapper))
195 lockmgr_note_shared_acquire(struct lock *lk, int contested,
196 uint64_t waittime, const char *file, int line, int flags)
199 LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(lockmgr__acquire, lk, contested,
200 waittime, file, line, LOCKSTAT_READER);
201 LOCK_LOG_LOCK("SLOCK", &lk->lock_object, 0, 0, file, line);
202 WITNESS_LOCK(&lk->lock_object, LK_TRYWIT(flags), file, line);
203 TD_LOCKS_INC(curthread);
204 TD_SLOCKS_INC(curthread);
209 lockmgr_note_shared_release(struct lock *lk, const char *file, int line)
212 WITNESS_UNLOCK(&lk->lock_object, 0, file, line);
213 LOCK_LOG_LOCK("SUNLOCK", &lk->lock_object, 0, 0, file, line);
214 TD_LOCKS_DEC(curthread);
215 TD_SLOCKS_DEC(curthread);
219 lockmgr_note_exclusive_acquire(struct lock *lk, int contested,
220 uint64_t waittime, const char *file, int line, int flags)
223 LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(lockmgr__acquire, lk, contested,
224 waittime, file, line, LOCKSTAT_WRITER);
225 LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0, lk->lk_recurse, file, line);
226 WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE | LK_TRYWIT(flags), file,
228 TD_LOCKS_INC(curthread);
233 lockmgr_note_exclusive_release(struct lock *lk, const char *file, int line)
236 if (LK_HOLDER(lk->lk_lock) != LK_KERNPROC) {
237 WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line);
238 TD_LOCKS_DEC(curthread);
240 LOCK_LOG_LOCK("XUNLOCK", &lk->lock_object, 0, lk->lk_recurse, file,
244 static __inline struct thread *
245 lockmgr_xholder(const struct lock *lk)
250 return ((x & LK_SHARE) ? NULL : (struct thread *)LK_HOLDER(x));
254 * It assumes sleepq_lock held and returns with this one unheld.
255 * It also assumes the generic interlock is sane and previously checked.
256 * If LK_INTERLOCK is specified the interlock is not reacquired after the
260 sleeplk(struct lock *lk, u_int flags, struct lock_object *ilk,
261 const char *wmesg, int pri, int timo, int queue)
264 struct lock_class *class;
267 class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL;
268 catch = pri & PCATCH;
272 LOCK_LOG3(lk, "%s: %p blocking on the %s sleepqueue", __func__, lk,
273 (queue == SQ_EXCLUSIVE_QUEUE) ? "exclusive" : "shared");
275 if (flags & LK_INTERLOCK)
276 class->lc_unlock(ilk);
277 if (queue == SQ_EXCLUSIVE_QUEUE && (flags & LK_SLEEPFAIL) != 0)
280 sleepq_add(&lk->lock_object, NULL, wmesg, SLEEPQ_LK | (catch ?
281 SLEEPQ_INTERRUPTIBLE : 0), queue);
282 if ((flags & LK_TIMELOCK) && timo)
283 sleepq_set_timeout(&lk->lock_object, timo);
286 * Decisional switch for real sleeping.
288 if ((flags & LK_TIMELOCK) && timo && catch)
289 error = sleepq_timedwait_sig(&lk->lock_object, pri);
290 else if ((flags & LK_TIMELOCK) && timo)
291 error = sleepq_timedwait(&lk->lock_object, pri);
293 error = sleepq_wait_sig(&lk->lock_object, pri);
295 sleepq_wait(&lk->lock_object, pri);
297 if ((flags & LK_SLEEPFAIL) && error == 0)
304 wakeupshlk(struct lock *lk, const char *file, int line)
306 uintptr_t v, x, orig_x;
308 int queue, wakeup_swapper;
313 if (lockmgr_sunlock_try(lk, &x))
317 * We should have a sharer with waiters, so enter the hard
318 * path in order to handle wakeups correctly.
320 sleepq_lock(&lk->lock_object);
321 orig_x = lk->lk_lock;
323 x = orig_x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS);
327 * If the lock has exclusive waiters, give them preference in
328 * order to avoid deadlock with shared runners up.
329 * If interruptible sleeps left the exclusive queue empty
330 * avoid a starvation for the threads sleeping on the shared
331 * queue by giving them precedence and cleaning up the
332 * exclusive waiters bit anyway.
333 * Please note that lk_exslpfail count may be lying about
334 * the real number of waiters with the LK_SLEEPFAIL flag on
335 * because they may be used in conjunction with interruptible
336 * sleeps so lk_exslpfail might be considered an 'upper limit'
337 * bound, including the edge cases.
339 realexslp = sleepq_sleepcnt(&lk->lock_object,
341 if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) {
342 if (lk->lk_exslpfail < realexslp) {
343 lk->lk_exslpfail = 0;
344 queue = SQ_EXCLUSIVE_QUEUE;
345 v |= (x & LK_SHARED_WAITERS);
347 lk->lk_exslpfail = 0;
349 "%s: %p has only LK_SLEEPFAIL sleepers",
352 "%s: %p waking up threads on the exclusive queue",
355 sleepq_broadcast(&lk->lock_object,
356 SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE);
357 queue = SQ_SHARED_QUEUE;
363 * Exclusive waiters sleeping with LK_SLEEPFAIL on
364 * and using interruptible sleeps/timeout may have
365 * left spourious lk_exslpfail counts on, so clean
368 lk->lk_exslpfail = 0;
369 queue = SQ_SHARED_QUEUE;
372 if (lockmgr_sunlock_try(lk, &orig_x)) {
373 sleepq_release(&lk->lock_object);
377 x |= LK_SHARERS_LOCK(1);
378 if (!atomic_fcmpset_rel_ptr(&lk->lk_lock, &x, v)) {
382 LOCK_LOG3(lk, "%s: %p waking up threads on the %s queue",
383 __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" :
385 wakeup_swapper |= sleepq_broadcast(&lk->lock_object, SLEEPQ_LK,
387 sleepq_release(&lk->lock_object);
391 LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER);
392 return (wakeup_swapper);
396 assert_lockmgr(const struct lock_object *lock, int what)
399 panic("lockmgr locks do not support assertions");
403 lock_lockmgr(struct lock_object *lock, uintptr_t how)
406 panic("lockmgr locks do not support sleep interlocking");
410 unlock_lockmgr(struct lock_object *lock)
413 panic("lockmgr locks do not support sleep interlocking");
418 owner_lockmgr(const struct lock_object *lock, struct thread **owner)
421 panic("lockmgr locks do not support owner inquiring");
426 lockinit(struct lock *lk, int pri, const char *wmesg, int timo, int flags)
430 MPASS((flags & ~LK_INIT_MASK) == 0);
431 ASSERT_ATOMIC_LOAD_PTR(lk->lk_lock,
432 ("%s: lockmgr not aligned for %s: %p", __func__, wmesg,
435 iflags = LO_SLEEPABLE | LO_UPGRADABLE;
436 if (flags & LK_CANRECURSE)
437 iflags |= LO_RECURSABLE;
438 if ((flags & LK_NODUP) == 0)
440 if (flags & LK_NOPROFILE)
441 iflags |= LO_NOPROFILE;
442 if ((flags & LK_NOWITNESS) == 0)
443 iflags |= LO_WITNESS;
444 if (flags & LK_QUIET)
446 if (flags & LK_IS_VNODE)
447 iflags |= LO_IS_VNODE;
450 iflags |= flags & LK_NOSHARE;
452 lock_init(&lk->lock_object, &lock_class_lockmgr, wmesg, NULL, iflags);
453 lk->lk_lock = LK_UNLOCKED;
455 lk->lk_exslpfail = 0;
462 * XXX: Gross hacks to manipulate external lock flags after
463 * initialization. Used for certain vnode and buf locks.
466 lockallowshare(struct lock *lk)
469 lockmgr_assert(lk, KA_XLOCKED);
470 lk->lock_object.lo_flags &= ~LK_NOSHARE;
474 lockdisableshare(struct lock *lk)
477 lockmgr_assert(lk, KA_XLOCKED);
478 lk->lock_object.lo_flags |= LK_NOSHARE;
482 lockallowrecurse(struct lock *lk)
485 lockmgr_assert(lk, KA_XLOCKED);
486 lk->lock_object.lo_flags |= LO_RECURSABLE;
490 lockdisablerecurse(struct lock *lk)
493 lockmgr_assert(lk, KA_XLOCKED);
494 lk->lock_object.lo_flags &= ~LO_RECURSABLE;
498 lockdestroy(struct lock *lk)
501 KASSERT(lk->lk_lock == LK_UNLOCKED, ("lockmgr still held"));
502 KASSERT(lk->lk_recurse == 0, ("lockmgr still recursed"));
503 KASSERT(lk->lk_exslpfail == 0, ("lockmgr still exclusive waiters"));
504 lock_destroy(&lk->lock_object);
507 static bool __always_inline
508 lockmgr_slock_try(struct lock *lk, uintptr_t *xp, int flags, bool fp)
512 * If no other thread has an exclusive lock, or
513 * no exclusive waiter is present, bump the count of
514 * sharers. Since we have to preserve the state of
515 * waiters, if we fail to acquire the shared lock
516 * loop back and retry.
519 while (LK_CAN_SHARE(*xp, flags, fp)) {
520 if (atomic_fcmpset_acq_ptr(&lk->lk_lock, xp,
521 *xp + LK_ONE_SHARER)) {
528 static bool __always_inline
529 lockmgr_sunlock_try(struct lock *lk, uintptr_t *xp)
533 if (LK_SHARERS(*xp) > 1 || !(*xp & LK_ALL_WAITERS)) {
534 if (atomic_fcmpset_rel_ptr(&lk->lk_lock, xp,
535 *xp - LK_ONE_SHARER))
544 static __noinline int
545 lockmgr_slock_hard(struct lock *lk, u_int flags, struct lock_object *ilk,
546 const char *file, int line, struct lockmgr_wait *lwa)
554 uint64_t sleep_time = 0;
556 #ifdef LOCK_PROFILING
557 uint64_t waittime = 0;
561 if (KERNEL_PANICKED())
564 tid = (uintptr_t)curthread;
566 if (LK_CAN_WITNESS(flags))
567 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER,
568 file, line, flags & LK_INTERLOCK ? ilk : NULL);
570 if (lockmgr_slock_try(lk, &x, flags, false))
573 PMC_SOFT_CALL( , , lock, failed);
575 lock_profile_obtain_lock_failed(&lk->lock_object,
576 &contested, &waittime);
579 * If the lock is already held by curthread in
580 * exclusive way avoid a deadlock.
582 if (LK_HOLDER(x) == tid) {
584 "%s: %p already held in exclusive mode",
591 * If the lock is expected to not sleep just give up
594 if (LK_TRYOP(flags)) {
595 LOCK_LOG2(lk, "%s: %p fails the try operation",
602 * Acquire the sleepqueue chain lock because we
603 * probabilly will need to manipulate waiters flags.
605 sleepq_lock(&lk->lock_object);
610 * if the lock can be acquired in shared mode, try
613 if (LK_CAN_SHARE(x, flags, false)) {
614 sleepq_release(&lk->lock_object);
619 * Try to set the LK_SHARED_WAITERS flag. If we fail,
620 * loop back and retry.
622 if ((x & LK_SHARED_WAITERS) == 0) {
623 if (!atomic_fcmpset_acq_ptr(&lk->lk_lock, &x,
624 x | LK_SHARED_WAITERS)) {
627 LOCK_LOG2(lk, "%s: %p set shared waiters flag",
632 iwmesg = lk->lock_object.lo_name;
636 iwmesg = lwa->iwmesg;
642 * As far as we have been unable to acquire the
643 * shared lock and the shared waiters flag is set,
647 sleep_time -= lockstat_nsecs(&lk->lock_object);
649 error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo,
652 sleep_time += lockstat_nsecs(&lk->lock_object);
654 flags &= ~LK_INTERLOCK;
657 "%s: interrupted sleep for %p with %d",
658 __func__, lk, error);
661 LOCK_LOG2(lk, "%s: %p resuming from the sleep queue",
667 LOCKSTAT_RECORD4(lockmgr__block, lk, sleep_time,
668 LOCKSTAT_READER, (x & LK_SHARE) == 0,
669 (x & LK_SHARE) == 0 ? 0 : LK_SHARERS(x));
671 #ifdef LOCK_PROFILING
672 lockmgr_note_shared_acquire(lk, contested, waittime,
675 lockmgr_note_shared_acquire(lk, 0, 0, file, line,
681 lockmgr_exit(flags, ilk, 0);
685 static __noinline int
686 lockmgr_xlock_hard(struct lock *lk, u_int flags, struct lock_object *ilk,
687 const char *file, int line, struct lockmgr_wait *lwa)
689 struct lock_class *class;
696 uint64_t sleep_time = 0;
698 #ifdef LOCK_PROFILING
699 uint64_t waittime = 0;
703 if (KERNEL_PANICKED())
706 tid = (uintptr_t)curthread;
708 if (LK_CAN_WITNESS(flags))
709 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER |
710 LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ?
714 * If curthread already holds the lock and this one is
715 * allowed to recurse, simply recurse on it.
717 if (lockmgr_xlocked(lk)) {
718 if ((flags & LK_CANRECURSE) == 0 &&
719 (lk->lock_object.lo_flags & LO_RECURSABLE) == 0) {
721 * If the lock is expected to not panic just
722 * give up and return.
724 if (LK_TRYOP(flags)) {
726 "%s: %p fails the try operation",
731 if (flags & LK_INTERLOCK) {
732 class = LOCK_CLASS(ilk);
733 class->lc_unlock(ilk);
736 panic("%s: recursing on non recursive lockmgr %p "
737 "@ %s:%d\n", __func__, lk, file, line);
740 LOCK_LOG2(lk, "%s: %p recursing", __func__, lk);
741 LOCK_LOG_LOCK("XLOCK", &lk->lock_object, 0,
742 lk->lk_recurse, file, line);
743 WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE |
744 LK_TRYWIT(flags), file, line);
745 TD_LOCKS_INC(curthread);
750 if (lk->lk_lock == LK_UNLOCKED &&
751 atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid))
754 PMC_SOFT_CALL( , , lock, failed);
756 lock_profile_obtain_lock_failed(&lk->lock_object,
757 &contested, &waittime);
760 * If the lock is expected to not sleep just give up
763 if (LK_TRYOP(flags)) {
764 LOCK_LOG2(lk, "%s: %p fails the try operation",
771 * Acquire the sleepqueue chain lock because we
772 * probabilly will need to manipulate waiters flags.
774 sleepq_lock(&lk->lock_object);
779 * if the lock has been released while we spun on
780 * the sleepqueue chain lock just try again.
782 if (x == LK_UNLOCKED) {
783 sleepq_release(&lk->lock_object);
788 * The lock can be in the state where there is a
789 * pending queue of waiters, but still no owner.
790 * This happens when the lock is contested and an
791 * owner is going to claim the lock.
792 * If curthread is the one successfully acquiring it
793 * claim lock ownership and return, preserving waiters
796 v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS);
797 if ((x & ~v) == LK_UNLOCKED) {
798 v &= ~LK_EXCLUSIVE_SPINNERS;
799 if (atomic_fcmpset_acq_ptr(&lk->lk_lock, &x,
801 sleepq_release(&lk->lock_object);
803 "%s: %p claimed by a new writer",
811 * Try to set the LK_EXCLUSIVE_WAITERS flag. If we
812 * fail, loop back and retry.
814 if ((x & LK_EXCLUSIVE_WAITERS) == 0) {
815 if (!atomic_fcmpset_ptr(&lk->lk_lock, &x,
816 x | LK_EXCLUSIVE_WAITERS)) {
819 LOCK_LOG2(lk, "%s: %p set excl waiters flag",
824 iwmesg = lk->lock_object.lo_name;
828 iwmesg = lwa->iwmesg;
834 * As far as we have been unable to acquire the
835 * exclusive lock and the exclusive waiters flag
836 * is set, we will sleep.
839 sleep_time -= lockstat_nsecs(&lk->lock_object);
841 error = sleeplk(lk, flags, ilk, iwmesg, ipri, itimo,
844 sleep_time += lockstat_nsecs(&lk->lock_object);
846 flags &= ~LK_INTERLOCK;
849 "%s: interrupted sleep for %p with %d",
850 __func__, lk, error);
853 LOCK_LOG2(lk, "%s: %p resuming from the sleep queue",
859 LOCKSTAT_RECORD4(lockmgr__block, lk, sleep_time,
860 LOCKSTAT_WRITER, (x & LK_SHARE) == 0,
861 (x & LK_SHARE) == 0 ? 0 : LK_SHARERS(x));
863 #ifdef LOCK_PROFILING
864 lockmgr_note_exclusive_acquire(lk, contested, waittime,
867 lockmgr_note_exclusive_acquire(lk, 0, 0, file, line,
873 lockmgr_exit(flags, ilk, 0);
877 static __noinline int
878 lockmgr_upgrade(struct lock *lk, u_int flags, struct lock_object *ilk,
879 const char *file, int line, struct lockmgr_wait *lwa)
883 int wakeup_swapper = 0;
886 if (KERNEL_PANICKED())
889 tid = (uintptr_t)curthread;
891 _lockmgr_assert(lk, KA_SLOCKED, file, line);
893 x = v & LK_ALL_WAITERS;
894 v &= LK_EXCLUSIVE_SPINNERS;
897 * Try to switch from one shared lock to an exclusive one.
898 * We need to preserve waiters flags during the operation.
900 if (atomic_cmpset_ptr(&lk->lk_lock, LK_SHARERS_LOCK(1) | x | v,
902 LOCK_LOG_LOCK("XUPGRADE", &lk->lock_object, 0, 0, file,
904 WITNESS_UPGRADE(&lk->lock_object, LOP_EXCLUSIVE |
905 LK_TRYWIT(flags), file, line);
906 LOCKSTAT_RECORD0(lockmgr__upgrade, lk);
907 TD_SLOCKS_DEC(curthread);
911 op = flags & LK_TYPE_MASK;
914 * In LK_TRYUPGRADE mode, do not drop the lock,
915 * returning EBUSY instead.
917 if (op == LK_TRYUPGRADE) {
918 LOCK_LOG2(lk, "%s: %p failed the nowait upgrade",
925 * We have been unable to succeed in upgrading, so just
926 * give up the shared lock.
928 lockmgr_note_shared_release(lk, file, line);
929 wakeup_swapper |= wakeupshlk(lk, file, line);
930 error = lockmgr_xlock_hard(lk, flags, ilk, file, line, lwa);
931 flags &= ~LK_INTERLOCK;
933 lockmgr_exit(flags, ilk, wakeup_swapper);
938 lockmgr_lock_flags(struct lock *lk, u_int flags, struct lock_object *ilk,
939 const char *file, int line)
941 struct lock_class *class;
946 if (KERNEL_PANICKED())
949 op = flags & LK_TYPE_MASK;
953 if (LK_CAN_WITNESS(flags))
954 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER,
955 file, line, flags & LK_INTERLOCK ? ilk : NULL);
956 if (__predict_false(lk->lock_object.lo_flags & LK_NOSHARE))
958 if (lockmgr_slock_try(lk, &x, flags, true)) {
959 lockmgr_note_shared_acquire(lk, 0, 0,
963 return (lockmgr_slock_hard(lk, flags, ilk, file, line,
968 if (LK_CAN_WITNESS(flags))
969 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER |
970 LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ?
972 tid = (uintptr_t)curthread;
973 if (lk->lk_lock == LK_UNLOCKED &&
974 atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) {
975 lockmgr_note_exclusive_acquire(lk, 0, 0, file, line,
979 return (lockmgr_xlock_hard(lk, flags, ilk, file, line,
985 return (lockmgr_upgrade(lk, flags, ilk, file, line, NULL));
989 if (__predict_true(locked)) {
990 if (__predict_false(flags & LK_INTERLOCK)) {
991 class = LOCK_CLASS(ilk);
992 class->lc_unlock(ilk);
996 return (__lockmgr_args(lk, flags, ilk, LK_WMESG_DEFAULT,
997 LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, file, line));
1001 static __noinline int
1002 lockmgr_sunlock_hard(struct lock *lk, uintptr_t x, u_int flags, struct lock_object *ilk,
1003 const char *file, int line)
1006 int wakeup_swapper = 0;
1008 if (KERNEL_PANICKED())
1011 wakeup_swapper = wakeupshlk(lk, file, line);
1014 lockmgr_exit(flags, ilk, wakeup_swapper);
1018 static __noinline int
1019 lockmgr_xunlock_hard(struct lock *lk, uintptr_t x, u_int flags, struct lock_object *ilk,
1020 const char *file, int line)
1023 int wakeup_swapper = 0;
1027 if (KERNEL_PANICKED())
1030 tid = (uintptr_t)curthread;
1033 * As first option, treact the lock as if it has not
1035 * Fix-up the tid var if the lock has been disowned.
1037 if (LK_HOLDER(x) == LK_KERNPROC)
1041 * The lock is held in exclusive mode.
1042 * If the lock is recursed also, then unrecurse it.
1044 if (lockmgr_xlocked_v(x) && lockmgr_recursed(lk)) {
1045 LOCK_LOG2(lk, "%s: %p unrecursing", __func__, lk);
1049 if (tid != LK_KERNPROC)
1050 LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk,
1053 if (x == tid && atomic_cmpset_rel_ptr(&lk->lk_lock, tid, LK_UNLOCKED))
1056 sleepq_lock(&lk->lock_object);
1061 * If the lock has exclusive waiters, give them
1062 * preference in order to avoid deadlock with
1063 * shared runners up.
1064 * If interruptible sleeps left the exclusive queue
1065 * empty avoid a starvation for the threads sleeping
1066 * on the shared queue by giving them precedence
1067 * and cleaning up the exclusive waiters bit anyway.
1068 * Please note that lk_exslpfail count may be lying
1069 * about the real number of waiters with the
1070 * LK_SLEEPFAIL flag on because they may be used in
1071 * conjunction with interruptible sleeps so
1072 * lk_exslpfail might be considered an 'upper limit'
1073 * bound, including the edge cases.
1075 MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
1076 realexslp = sleepq_sleepcnt(&lk->lock_object, SQ_EXCLUSIVE_QUEUE);
1077 if ((x & LK_EXCLUSIVE_WAITERS) != 0 && realexslp != 0) {
1078 if (lk->lk_exslpfail < realexslp) {
1079 lk->lk_exslpfail = 0;
1080 queue = SQ_EXCLUSIVE_QUEUE;
1081 v |= (x & LK_SHARED_WAITERS);
1083 lk->lk_exslpfail = 0;
1085 "%s: %p has only LK_SLEEPFAIL sleepers",
1088 "%s: %p waking up threads on the exclusive queue",
1090 wakeup_swapper = sleepq_broadcast(&lk->lock_object,
1091 SLEEPQ_LK, 0, SQ_EXCLUSIVE_QUEUE);
1092 queue = SQ_SHARED_QUEUE;
1097 * Exclusive waiters sleeping with LK_SLEEPFAIL
1098 * on and using interruptible sleeps/timeout
1099 * may have left spourious lk_exslpfail counts
1100 * on, so clean it up anyway.
1102 lk->lk_exslpfail = 0;
1103 queue = SQ_SHARED_QUEUE;
1106 LOCK_LOG3(lk, "%s: %p waking up threads on the %s queue",
1107 __func__, lk, queue == SQ_SHARED_QUEUE ? "shared" :
1109 atomic_store_rel_ptr(&lk->lk_lock, v);
1110 wakeup_swapper |= sleepq_broadcast(&lk->lock_object, SLEEPQ_LK, 0, queue);
1111 sleepq_release(&lk->lock_object);
1114 lockmgr_exit(flags, ilk, wakeup_swapper);
1119 * Lightweight entry points for common operations.
1121 * Functionality is similar to sx locks, in that none of the additional lockmgr
1122 * features are supported. To be clear, these are NOT supported:
1123 * 1. shared locking disablement
1124 * 2. returning with an error after sleep
1125 * 3. unlocking the interlock
1127 * If in doubt, use lockmgr_lock_flags.
1130 lockmgr_slock(struct lock *lk, u_int flags, const char *file, int line)
1134 MPASS((flags & LK_TYPE_MASK) == LK_SHARED);
1135 MPASS((flags & LK_INTERLOCK) == 0);
1136 MPASS((lk->lock_object.lo_flags & LK_NOSHARE) == 0);
1138 if (LK_CAN_WITNESS(flags))
1139 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER,
1141 if (__predict_true(lockmgr_slock_try(lk, &x, flags, true))) {
1142 lockmgr_note_shared_acquire(lk, 0, 0, file, line, flags);
1146 return (lockmgr_slock_hard(lk, flags, NULL, file, line, NULL));
1150 lockmgr_xlock(struct lock *lk, u_int flags, const char *file, int line)
1154 MPASS((flags & LK_TYPE_MASK) == LK_EXCLUSIVE);
1155 MPASS((flags & LK_INTERLOCK) == 0);
1157 if (LK_CAN_WITNESS(flags))
1158 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER |
1159 LOP_EXCLUSIVE, file, line, NULL);
1160 tid = (uintptr_t)curthread;
1161 if (atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) {
1162 lockmgr_note_exclusive_acquire(lk, 0, 0, file, line,
1167 return (lockmgr_xlock_hard(lk, flags, NULL, file, line, NULL));
1171 lockmgr_unlock(struct lock *lk)
1180 _lockmgr_assert(lk, KA_LOCKED, file, line);
1182 if (__predict_true(x & LK_SHARE) != 0) {
1183 lockmgr_note_shared_release(lk, file, line);
1184 if (lockmgr_sunlock_try(lk, &x)) {
1185 LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_READER);
1187 return (lockmgr_sunlock_hard(lk, x, LK_RELEASE, NULL, file, line));
1190 tid = (uintptr_t)curthread;
1191 lockmgr_note_exclusive_release(lk, file, line);
1192 if (!lockmgr_recursed(lk) &&
1193 atomic_cmpset_rel_ptr(&lk->lk_lock, tid, LK_UNLOCKED)) {
1194 LOCKSTAT_PROFILE_RELEASE_RWLOCK(lockmgr__release, lk, LOCKSTAT_WRITER);
1196 return (lockmgr_xunlock_hard(lk, x, LK_RELEASE, NULL, file, line));
1203 __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
1204 const char *wmesg, int pri, int timo, const char *file, int line)
1207 struct lockmgr_wait lwa;
1208 struct lock_class *class;
1210 uintptr_t tid, v, x;
1211 u_int op, realexslp;
1212 int error, ipri, itimo, queue, wakeup_swapper;
1213 #ifdef LOCK_PROFILING
1214 uint64_t waittime = 0;
1218 if (KERNEL_PANICKED())
1222 tid = (uintptr_t)curthread;
1223 op = (flags & LK_TYPE_MASK);
1224 iwmesg = (wmesg == LK_WMESG_DEFAULT) ? lk->lock_object.lo_name : wmesg;
1225 ipri = (pri == LK_PRIO_DEFAULT) ? lk->lk_pri : pri;
1226 itimo = (timo == LK_TIMO_DEFAULT) ? lk->lk_timo : timo;
1228 lwa.iwmesg = iwmesg;
1232 MPASS((flags & ~LK_TOTAL_MASK) == 0);
1233 KASSERT((op & (op - 1)) == 0,
1234 ("%s: Invalid requested operation @ %s:%d", __func__, file, line));
1235 KASSERT((flags & (LK_NOWAIT | LK_SLEEPFAIL)) == 0 ||
1236 (op != LK_DOWNGRADE && op != LK_RELEASE),
1237 ("%s: Invalid flags in regard of the operation desired @ %s:%d",
1238 __func__, file, line));
1239 KASSERT((flags & LK_INTERLOCK) == 0 || ilk != NULL,
1240 ("%s: LK_INTERLOCK passed without valid interlock @ %s:%d",
1241 __func__, file, line));
1242 KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread),
1243 ("%s: idle thread %p on lockmgr %s @ %s:%d", __func__, curthread,
1244 lk->lock_object.lo_name, file, line));
1246 class = (flags & LK_INTERLOCK) ? LOCK_CLASS(ilk) : NULL;
1248 if (lk->lock_object.lo_flags & LK_NOSHARE) {
1256 _lockmgr_assert(lk, KA_XLOCKED | KA_NOTRECURSED,
1258 if (flags & LK_INTERLOCK)
1259 class->lc_unlock(ilk);
1267 return (lockmgr_slock_hard(lk, flags, ilk, file, line, &lwa));
1271 return (lockmgr_upgrade(lk, flags, ilk, file, line, &lwa));
1274 return (lockmgr_xlock_hard(lk, flags, ilk, file, line, &lwa));
1277 _lockmgr_assert(lk, KA_XLOCKED, file, line);
1278 WITNESS_DOWNGRADE(&lk->lock_object, 0, file, line);
1281 * Panic if the lock is recursed.
1283 if (lockmgr_xlocked(lk) && lockmgr_recursed(lk)) {
1284 if (flags & LK_INTERLOCK)
1285 class->lc_unlock(ilk);
1286 panic("%s: downgrade a recursed lockmgr %s @ %s:%d\n",
1287 __func__, iwmesg, file, line);
1289 TD_SLOCKS_INC(curthread);
1292 * In order to preserve waiters flags, just spin.
1296 MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
1297 x &= LK_ALL_WAITERS;
1298 if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
1299 LK_SHARERS_LOCK(1) | x))
1303 LOCK_LOG_LOCK("XDOWNGRADE", &lk->lock_object, 0, 0, file, line);
1304 LOCKSTAT_RECORD0(lockmgr__downgrade, lk);
1307 _lockmgr_assert(lk, KA_LOCKED, file, line);
1310 if (__predict_true(x & LK_SHARE) != 0) {
1311 lockmgr_note_shared_release(lk, file, line);
1312 return (lockmgr_sunlock_hard(lk, x, flags, ilk, file, line));
1314 lockmgr_note_exclusive_release(lk, file, line);
1315 return (lockmgr_xunlock_hard(lk, x, flags, ilk, file, line));
1319 if (LK_CAN_WITNESS(flags))
1320 WITNESS_CHECKORDER(&lk->lock_object, LOP_NEWORDER |
1321 LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ?
1325 * Trying to drain a lock we already own will result in a
1328 if (lockmgr_xlocked(lk)) {
1329 if (flags & LK_INTERLOCK)
1330 class->lc_unlock(ilk);
1331 panic("%s: draining %s with the lock held @ %s:%d\n",
1332 __func__, iwmesg, file, line);
1336 if (lk->lk_lock == LK_UNLOCKED &&
1337 atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid))
1341 PMC_SOFT_CALL( , , lock, failed);
1343 lock_profile_obtain_lock_failed(&lk->lock_object,
1344 &contested, &waittime);
1347 * If the lock is expected to not sleep just give up
1350 if (LK_TRYOP(flags)) {
1351 LOCK_LOG2(lk, "%s: %p fails the try operation",
1358 * Acquire the sleepqueue chain lock because we
1359 * probabilly will need to manipulate waiters flags.
1361 sleepq_lock(&lk->lock_object);
1365 * if the lock has been released while we spun on
1366 * the sleepqueue chain lock just try again.
1368 if (x == LK_UNLOCKED) {
1369 sleepq_release(&lk->lock_object);
1373 v = x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS);
1374 if ((x & ~v) == LK_UNLOCKED) {
1375 v = (x & ~LK_EXCLUSIVE_SPINNERS);
1378 * If interruptible sleeps left the exclusive
1379 * queue empty avoid a starvation for the
1380 * threads sleeping on the shared queue by
1381 * giving them precedence and cleaning up the
1382 * exclusive waiters bit anyway.
1383 * Please note that lk_exslpfail count may be
1384 * lying about the real number of waiters with
1385 * the LK_SLEEPFAIL flag on because they may
1386 * be used in conjunction with interruptible
1387 * sleeps so lk_exslpfail might be considered
1388 * an 'upper limit' bound, including the edge
1391 if (v & LK_EXCLUSIVE_WAITERS) {
1392 queue = SQ_EXCLUSIVE_QUEUE;
1393 v &= ~LK_EXCLUSIVE_WAITERS;
1397 * Exclusive waiters sleeping with
1398 * LK_SLEEPFAIL on and using
1399 * interruptible sleeps/timeout may
1400 * have left spourious lk_exslpfail
1401 * counts on, so clean it up anyway.
1403 MPASS(v & LK_SHARED_WAITERS);
1404 lk->lk_exslpfail = 0;
1405 queue = SQ_SHARED_QUEUE;
1406 v &= ~LK_SHARED_WAITERS;
1408 if (queue == SQ_EXCLUSIVE_QUEUE) {
1410 sleepq_sleepcnt(&lk->lock_object,
1411 SQ_EXCLUSIVE_QUEUE);
1412 if (lk->lk_exslpfail >= realexslp) {
1413 lk->lk_exslpfail = 0;
1414 queue = SQ_SHARED_QUEUE;
1415 v &= ~LK_SHARED_WAITERS;
1416 if (realexslp != 0) {
1418 "%s: %p has only LK_SLEEPFAIL sleepers",
1421 "%s: %p waking up threads on the exclusive queue",
1427 SQ_EXCLUSIVE_QUEUE);
1430 lk->lk_exslpfail = 0;
1432 if (!atomic_cmpset_ptr(&lk->lk_lock, x, v)) {
1433 sleepq_release(&lk->lock_object);
1437 "%s: %p waking up all threads on the %s queue",
1438 __func__, lk, queue == SQ_SHARED_QUEUE ?
1439 "shared" : "exclusive");
1440 wakeup_swapper |= sleepq_broadcast(
1441 &lk->lock_object, SLEEPQ_LK, 0, queue);
1444 * If shared waiters have been woken up we need
1445 * to wait for one of them to acquire the lock
1446 * before to set the exclusive waiters in
1447 * order to avoid a deadlock.
1449 if (queue == SQ_SHARED_QUEUE) {
1450 for (v = lk->lk_lock;
1451 (v & LK_SHARE) && !LK_SHARERS(v);
1458 * Try to set the LK_EXCLUSIVE_WAITERS flag. If we
1459 * fail, loop back and retry.
1461 if ((x & LK_EXCLUSIVE_WAITERS) == 0) {
1462 if (!atomic_cmpset_ptr(&lk->lk_lock, x,
1463 x | LK_EXCLUSIVE_WAITERS)) {
1464 sleepq_release(&lk->lock_object);
1467 LOCK_LOG2(lk, "%s: %p set drain waiters flag",
1472 * As far as we have been unable to acquire the
1473 * exclusive lock and the exclusive waiters flag
1474 * is set, we will sleep.
1476 if (flags & LK_INTERLOCK) {
1477 class->lc_unlock(ilk);
1478 flags &= ~LK_INTERLOCK;
1481 sleepq_add(&lk->lock_object, NULL, iwmesg, SLEEPQ_LK,
1482 SQ_EXCLUSIVE_QUEUE);
1483 sleepq_wait(&lk->lock_object, ipri & PRIMASK);
1485 LOCK_LOG2(lk, "%s: %p resuming from the sleep queue",
1490 lock_profile_obtain_lock_success(&lk->lock_object,
1491 contested, waittime, file, line);
1492 LOCK_LOG_LOCK("DRAIN", &lk->lock_object, 0,
1493 lk->lk_recurse, file, line);
1494 WITNESS_LOCK(&lk->lock_object, LOP_EXCLUSIVE |
1495 LK_TRYWIT(flags), file, line);
1496 TD_LOCKS_INC(curthread);
1501 if (flags & LK_INTERLOCK)
1502 class->lc_unlock(ilk);
1503 panic("%s: unknown lockmgr request 0x%x\n", __func__, op);
1506 if (flags & LK_INTERLOCK)
1507 class->lc_unlock(ilk);
1515 _lockmgr_disown(struct lock *lk, const char *file, int line)
1519 if (SCHEDULER_STOPPED())
1522 tid = (uintptr_t)curthread;
1523 _lockmgr_assert(lk, KA_XLOCKED, file, line);
1526 * Panic if the lock is recursed.
1528 if (lockmgr_xlocked(lk) && lockmgr_recursed(lk))
1529 panic("%s: disown a recursed lockmgr @ %s:%d\n",
1530 __func__, file, line);
1533 * If the owner is already LK_KERNPROC just skip the whole operation.
1535 if (LK_HOLDER(lk->lk_lock) != tid)
1537 lock_profile_release_lock(&lk->lock_object);
1538 LOCKSTAT_RECORD1(lockmgr__disown, lk, LOCKSTAT_WRITER);
1539 LOCK_LOG_LOCK("XDISOWN", &lk->lock_object, 0, 0, file, line);
1540 WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line);
1541 TD_LOCKS_DEC(curthread);
1545 * In order to preserve waiters flags, just spin.
1549 MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
1550 x &= LK_ALL_WAITERS;
1551 if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
1559 lockmgr_printinfo(const struct lock *lk)
1564 if (lk->lk_lock == LK_UNLOCKED)
1565 printf("lock type %s: UNLOCKED\n", lk->lock_object.lo_name);
1566 else if (lk->lk_lock & LK_SHARE)
1567 printf("lock type %s: SHARED (count %ju)\n",
1568 lk->lock_object.lo_name,
1569 (uintmax_t)LK_SHARERS(lk->lk_lock));
1571 td = lockmgr_xholder(lk);
1572 if (td == (struct thread *)LK_KERNPROC)
1573 printf("lock type %s: EXCL by KERNPROC\n",
1574 lk->lock_object.lo_name);
1576 printf("lock type %s: EXCL by thread %p "
1577 "(pid %d, %s, tid %d)\n", lk->lock_object.lo_name,
1578 td, td->td_proc->p_pid, td->td_proc->p_comm,
1583 if (x & LK_EXCLUSIVE_WAITERS)
1584 printf(" with exclusive waiters pending\n");
1585 if (x & LK_SHARED_WAITERS)
1586 printf(" with shared waiters pending\n");
1587 if (x & LK_EXCLUSIVE_SPINNERS)
1588 printf(" with exclusive spinners pending\n");
1594 lockstatus(const struct lock *lk)
1603 if ((x & LK_SHARE) == 0) {
1604 if (v == (uintptr_t)curthread || v == LK_KERNPROC)
1608 } else if (x == LK_UNLOCKED)
1614 #ifdef INVARIANT_SUPPORT
1616 FEATURE(invariant_support,
1617 "Support for modules compiled with INVARIANTS option");
1620 #undef _lockmgr_assert
1624 _lockmgr_assert(const struct lock *lk, int what, const char *file, int line)
1628 if (KERNEL_PANICKED())
1632 case KA_SLOCKED | KA_NOTRECURSED:
1633 case KA_SLOCKED | KA_RECURSED:
1636 case KA_LOCKED | KA_NOTRECURSED:
1637 case KA_LOCKED | KA_RECURSED:
1641 * We cannot trust WITNESS if the lock is held in exclusive
1642 * mode and a call to lockmgr_disown() happened.
1643 * Workaround this skipping the check if the lock is held in
1644 * exclusive mode even for the KA_LOCKED case.
1646 if (slocked || (lk->lk_lock & LK_SHARE)) {
1647 witness_assert(&lk->lock_object, what, file, line);
1651 if (lk->lk_lock == LK_UNLOCKED ||
1652 ((lk->lk_lock & LK_SHARE) == 0 && (slocked ||
1653 (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk)))))
1654 panic("Lock %s not %slocked @ %s:%d\n",
1655 lk->lock_object.lo_name, slocked ? "share" : "",
1658 if ((lk->lk_lock & LK_SHARE) == 0) {
1659 if (lockmgr_recursed(lk)) {
1660 if (what & KA_NOTRECURSED)
1661 panic("Lock %s recursed @ %s:%d\n",
1662 lk->lock_object.lo_name, file,
1664 } else if (what & KA_RECURSED)
1665 panic("Lock %s not recursed @ %s:%d\n",
1666 lk->lock_object.lo_name, file, line);
1670 case KA_XLOCKED | KA_NOTRECURSED:
1671 case KA_XLOCKED | KA_RECURSED:
1672 if (!lockmgr_xlocked(lk) && !lockmgr_disowned(lk))
1673 panic("Lock %s not exclusively locked @ %s:%d\n",
1674 lk->lock_object.lo_name, file, line);
1675 if (lockmgr_recursed(lk)) {
1676 if (what & KA_NOTRECURSED)
1677 panic("Lock %s recursed @ %s:%d\n",
1678 lk->lock_object.lo_name, file, line);
1679 } else if (what & KA_RECURSED)
1680 panic("Lock %s not recursed @ %s:%d\n",
1681 lk->lock_object.lo_name, file, line);
1684 if (lockmgr_xlocked(lk) || lockmgr_disowned(lk))
1685 panic("Lock %s exclusively locked @ %s:%d\n",
1686 lk->lock_object.lo_name, file, line);
1689 panic("Unknown lockmgr assertion: %d @ %s:%d\n", what, file,
1697 lockmgr_chain(struct thread *td, struct thread **ownerp)
1699 const struct lock *lk;
1703 if (LOCK_CLASS(&lk->lock_object) != &lock_class_lockmgr)
1705 db_printf("blocked on lockmgr %s", lk->lock_object.lo_name);
1706 if (lk->lk_lock & LK_SHARE)
1707 db_printf("SHARED (count %ju)\n",
1708 (uintmax_t)LK_SHARERS(lk->lk_lock));
1710 db_printf("EXCL\n");
1711 *ownerp = lockmgr_xholder(lk);
1717 db_show_lockmgr(const struct lock_object *lock)
1720 const struct lock *lk;
1722 lk = (const struct lock *)lock;
1724 db_printf(" state: ");
1725 if (lk->lk_lock == LK_UNLOCKED)
1726 db_printf("UNLOCKED\n");
1727 else if (lk->lk_lock & LK_SHARE)
1728 db_printf("SLOCK: %ju\n", (uintmax_t)LK_SHARERS(lk->lk_lock));
1730 td = lockmgr_xholder(lk);
1731 if (td == (struct thread *)LK_KERNPROC)
1732 db_printf("XLOCK: LK_KERNPROC\n");
1734 db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td,
1735 td->td_tid, td->td_proc->p_pid,
1736 td->td_proc->p_comm);
1737 if (lockmgr_recursed(lk))
1738 db_printf(" recursed: %d\n", lk->lk_recurse);
1740 db_printf(" waiters: ");
1741 switch (lk->lk_lock & LK_ALL_WAITERS) {
1742 case LK_SHARED_WAITERS:
1743 db_printf("shared\n");
1745 case LK_EXCLUSIVE_WAITERS:
1746 db_printf("exclusive\n");
1748 case LK_ALL_WAITERS:
1749 db_printf("shared and exclusive\n");
1752 db_printf("none\n");
1754 db_printf(" spinners: ");
1755 if (lk->lk_lock & LK_EXCLUSIVE_SPINNERS)
1756 db_printf("exclusive\n");
1758 db_printf("none\n");