Index: stable/11/sys/kern/kern_condvar.c =================================================================== --- stable/11/sys/kern/kern_condvar.c (revision 315385) +++ stable/11/sys/kern/kern_condvar.c (revision 315386) @@ -1,446 +1,446 @@ /*- * Copyright (c) 2000 Jake Burkholder . * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include "opt_ktrace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #include #endif /* * A bound below which cv_waiters is valid. Once cv_waiters reaches this bound, * cv_signal must manually check the wait queue for threads. */ #define CV_WAITERS_BOUND INT_MAX #define CV_WAITERS_INC(cvp) do { \ if ((cvp)->cv_waiters < CV_WAITERS_BOUND) \ (cvp)->cv_waiters++; \ } while (0) /* * Common sanity checks for cv_wait* functions. */ #define CV_ASSERT(cvp, lock, td) do { \ KASSERT((td) != NULL, ("%s: td NULL", __func__)); \ KASSERT(TD_IS_RUNNING(td), ("%s: not TDS_RUNNING", __func__)); \ KASSERT((cvp) != NULL, ("%s: cvp NULL", __func__)); \ KASSERT((lock) != NULL, ("%s: lock NULL", __func__)); \ } while (0) /* * Initialize a condition variable. Must be called before use. */ void cv_init(struct cv *cvp, const char *desc) { cvp->cv_description = desc; cvp->cv_waiters = 0; } /* * Destroy a condition variable. The condition variable must be re-initialized * in order to be re-used. */ void cv_destroy(struct cv *cvp) { #ifdef INVARIANTS struct sleepqueue *sq; sleepq_lock(cvp); sq = sleepq_lookup(cvp); sleepq_release(cvp); KASSERT(sq == NULL, ("%s: associated sleep queue non-empty", __func__)); #endif } /* * Wait on a condition variable. The current thread is placed on the condition * variable's wait queue and suspended. A cv_signal or cv_broadcast on the same * condition variable will resume the thread. The mutex is released before * sleeping and will be held on return. It is recommended that the mutex be * held when cv_signal or cv_broadcast are called. */ void _cv_wait(struct cv *cvp, struct lock_object *lock) { WITNESS_SAVE_DECL(lock_witness); struct lock_class *class; struct thread *td; uintptr_t lock_state; td = curthread; lock_state = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, cv_wmesg(cvp)); #endif CV_ASSERT(cvp, lock, td); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Waiting on \"%s\"", cvp->cv_description); class = LOCK_CLASS(lock); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return; sleepq_lock(cvp); CV_WAITERS_INC(cvp); if (lock == &Giant.lock_object) mtx_assert(&Giant, MA_OWNED); DROP_GIANT(); sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0); if (lock != &Giant.lock_object) { if (class->lc_flags & LC_SLEEPABLE) sleepq_release(cvp); WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); if (class->lc_flags & LC_SLEEPABLE) sleepq_lock(cvp); } sleepq_wait(cvp, 0); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, cv_wmesg(cvp)); #endif PICKUP_GIANT(); if (lock != &Giant.lock_object) { class->lc_lock(lock, lock_state); WITNESS_RESTORE(lock, lock_witness); } } /* * Wait on a condition variable. This function differs from cv_wait by * not acquiring the mutex after condition variable was signaled. */ void _cv_wait_unlock(struct cv *cvp, struct lock_object *lock) { struct lock_class *class; struct thread *td; td = curthread; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, cv_wmesg(cvp)); #endif CV_ASSERT(cvp, lock, td); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Waiting on \"%s\"", cvp->cv_description); KASSERT(lock != &Giant.lock_object, ("cv_wait_unlock cannot be used with Giant")); class = LOCK_CLASS(lock); - if (SCHEDULER_STOPPED()) { + if (SCHEDULER_STOPPED_TD(td)) { class->lc_unlock(lock); return; } sleepq_lock(cvp); CV_WAITERS_INC(cvp); DROP_GIANT(); sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0); if (class->lc_flags & LC_SLEEPABLE) sleepq_release(cvp); class->lc_unlock(lock); if (class->lc_flags & LC_SLEEPABLE) sleepq_lock(cvp); sleepq_wait(cvp, 0); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, cv_wmesg(cvp)); #endif PICKUP_GIANT(); } /* * Wait on a condition variable, allowing interruption by signals. Return 0 if * the thread was resumed with cv_signal or cv_broadcast, EINTR or ERESTART if * a signal was caught. If ERESTART is returned the system call should be * restarted if possible. */ int _cv_wait_sig(struct cv *cvp, struct lock_object *lock) { WITNESS_SAVE_DECL(lock_witness); struct lock_class *class; struct thread *td; uintptr_t lock_state; int rval; td = curthread; lock_state = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, cv_wmesg(cvp)); #endif CV_ASSERT(cvp, lock, td); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Waiting on \"%s\"", cvp->cv_description); class = LOCK_CLASS(lock); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return (0); sleepq_lock(cvp); CV_WAITERS_INC(cvp); if (lock == &Giant.lock_object) mtx_assert(&Giant, MA_OWNED); DROP_GIANT(); sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR | SLEEPQ_INTERRUPTIBLE, 0); if (lock != &Giant.lock_object) { if (class->lc_flags & LC_SLEEPABLE) sleepq_release(cvp); WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); if (class->lc_flags & LC_SLEEPABLE) sleepq_lock(cvp); } rval = sleepq_wait_sig(cvp, 0); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, cv_wmesg(cvp)); #endif PICKUP_GIANT(); if (lock != &Giant.lock_object) { class->lc_lock(lock, lock_state); WITNESS_RESTORE(lock, lock_witness); } return (rval); } /* * Wait on a condition variable for (at most) the value specified in sbt * argument. Returns 0 if the process was resumed by cv_signal or cv_broadcast, * EWOULDBLOCK if the timeout expires. */ int _cv_timedwait_sbt(struct cv *cvp, struct lock_object *lock, sbintime_t sbt, sbintime_t pr, int flags) { WITNESS_SAVE_DECL(lock_witness); struct lock_class *class; struct thread *td; int lock_state, rval; td = curthread; lock_state = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, cv_wmesg(cvp)); #endif CV_ASSERT(cvp, lock, td); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Waiting on \"%s\"", cvp->cv_description); class = LOCK_CLASS(lock); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return (0); sleepq_lock(cvp); CV_WAITERS_INC(cvp); if (lock == &Giant.lock_object) mtx_assert(&Giant, MA_OWNED); DROP_GIANT(); sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR, 0); sleepq_set_timeout_sbt(cvp, sbt, pr, flags); if (lock != &Giant.lock_object) { if (class->lc_flags & LC_SLEEPABLE) sleepq_release(cvp); WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); if (class->lc_flags & LC_SLEEPABLE) sleepq_lock(cvp); } rval = sleepq_timedwait(cvp, 0); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, cv_wmesg(cvp)); #endif PICKUP_GIANT(); if (lock != &Giant.lock_object) { class->lc_lock(lock, lock_state); WITNESS_RESTORE(lock, lock_witness); } return (rval); } /* * Wait on a condition variable for (at most) the value specified in sbt * argument, allowing interruption by signals. * Returns 0 if the thread was resumed by cv_signal or cv_broadcast, * EWOULDBLOCK if the timeout expires, and EINTR or ERESTART if a signal * was caught. */ int _cv_timedwait_sig_sbt(struct cv *cvp, struct lock_object *lock, sbintime_t sbt, sbintime_t pr, int flags) { WITNESS_SAVE_DECL(lock_witness); struct lock_class *class; struct thread *td; int lock_state, rval; td = curthread; lock_state = 0; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, cv_wmesg(cvp)); #endif CV_ASSERT(cvp, lock, td); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Waiting on \"%s\"", cvp->cv_description); class = LOCK_CLASS(lock); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return (0); sleepq_lock(cvp); CV_WAITERS_INC(cvp); if (lock == &Giant.lock_object) mtx_assert(&Giant, MA_OWNED); DROP_GIANT(); sleepq_add(cvp, lock, cvp->cv_description, SLEEPQ_CONDVAR | SLEEPQ_INTERRUPTIBLE, 0); sleepq_set_timeout_sbt(cvp, sbt, pr, flags); if (lock != &Giant.lock_object) { if (class->lc_flags & LC_SLEEPABLE) sleepq_release(cvp); WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); if (class->lc_flags & LC_SLEEPABLE) sleepq_lock(cvp); } rval = sleepq_timedwait_sig(cvp, 0); #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, cv_wmesg(cvp)); #endif PICKUP_GIANT(); if (lock != &Giant.lock_object) { class->lc_lock(lock, lock_state); WITNESS_RESTORE(lock, lock_witness); } return (rval); } /* * Signal a condition variable, wakes up one waiting thread. Will also wakeup * the swapper if the process is not in memory, so that it can bring the * sleeping process in. Note that this may also result in additional threads * being made runnable. Should be called with the same mutex as was passed to * cv_wait held. */ void cv_signal(struct cv *cvp) { int wakeup_swapper; if (cvp->cv_waiters == 0) return; wakeup_swapper = 0; sleepq_lock(cvp); if (cvp->cv_waiters > 0) { if (cvp->cv_waiters == CV_WAITERS_BOUND && sleepq_lookup(cvp) == NULL) { cvp->cv_waiters = 0; } else { if (cvp->cv_waiters < CV_WAITERS_BOUND) cvp->cv_waiters--; wakeup_swapper = sleepq_signal(cvp, SLEEPQ_CONDVAR, 0, 0); } } sleepq_release(cvp); if (wakeup_swapper) kick_proc0(); } /* * Broadcast a signal to a condition variable. Wakes up all waiting threads. * Should be called with the same mutex as was passed to cv_wait held. */ void cv_broadcastpri(struct cv *cvp, int pri) { int wakeup_swapper; if (cvp->cv_waiters == 0) return; /* * XXX sleepq_broadcast pri argument changed from -1 meaning * no pri to 0 meaning no pri. */ wakeup_swapper = 0; if (pri == -1) pri = 0; sleepq_lock(cvp); if (cvp->cv_waiters > 0) { cvp->cv_waiters = 0; wakeup_swapper = sleepq_broadcast(cvp, SLEEPQ_CONDVAR, pri, 0); } sleepq_release(cvp); if (wakeup_swapper) kick_proc0(); } Index: stable/11/sys/kern/kern_mutex.c =================================================================== --- stable/11/sys/kern/kern_mutex.c (revision 315385) +++ stable/11/sys/kern/kern_mutex.c (revision 315386) @@ -1,1116 +1,1110 @@ /*- * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Berkeley Software Design Inc's name may not be used to endorse or * promote products derived from this software without specific prior * written permission. * * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ */ /* * Machine independent bits of mutex implementation. */ #include __FBSDID("$FreeBSD$"); #include "opt_adaptive_mutexes.h" #include "opt_ddb.h" #include "opt_hwpmc_hooks.h" #include "opt_sched.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) && !defined(NO_ADAPTIVE_MUTEXES) #define ADAPTIVE_MUTEXES #endif #ifdef HWPMC_HOOKS #include PMC_SOFT_DEFINE( , , lock, failed); #endif /* * Return the mutex address when the lock cookie address is provided. * This functionality assumes that struct mtx* have a member named mtx_lock. */ #define mtxlock2mtx(c) (__containerof(c, struct mtx, mtx_lock)) /* * Internal utility macros. */ #define mtx_unowned(m) ((m)->mtx_lock == MTX_UNOWNED) #define mtx_destroyed(m) ((m)->mtx_lock == MTX_DESTROYED) static void assert_mtx(const struct lock_object *lock, int what); #ifdef DDB static void db_show_mtx(const struct lock_object *lock); #endif static void lock_mtx(struct lock_object *lock, uintptr_t how); static void lock_spin(struct lock_object *lock, uintptr_t how); #ifdef KDTRACE_HOOKS static int owner_mtx(const struct lock_object *lock, struct thread **owner); #endif static uintptr_t unlock_mtx(struct lock_object *lock); static uintptr_t unlock_spin(struct lock_object *lock); /* * Lock classes for sleep and spin mutexes. */ struct lock_class lock_class_mtx_sleep = { .lc_name = "sleep mutex", .lc_flags = LC_SLEEPLOCK | LC_RECURSABLE, .lc_assert = assert_mtx, #ifdef DDB .lc_ddb_show = db_show_mtx, #endif .lc_lock = lock_mtx, .lc_unlock = unlock_mtx, #ifdef KDTRACE_HOOKS .lc_owner = owner_mtx, #endif }; struct lock_class lock_class_mtx_spin = { .lc_name = "spin mutex", .lc_flags = LC_SPINLOCK | LC_RECURSABLE, .lc_assert = assert_mtx, #ifdef DDB .lc_ddb_show = db_show_mtx, #endif .lc_lock = lock_spin, .lc_unlock = unlock_spin, #ifdef KDTRACE_HOOKS .lc_owner = owner_mtx, #endif }; #ifdef ADAPTIVE_MUTEXES static SYSCTL_NODE(_debug, OID_AUTO, mtx, CTLFLAG_RD, NULL, "mtx debugging"); static struct lock_delay_config __read_mostly mtx_delay; SYSCTL_INT(_debug_mtx, OID_AUTO, delay_base, CTLFLAG_RW, &mtx_delay.base, 0, ""); SYSCTL_INT(_debug_mtx, OID_AUTO, delay_max, CTLFLAG_RW, &mtx_delay.max, 0, ""); LOCK_DELAY_SYSINIT_DEFAULT(mtx_delay); #endif static SYSCTL_NODE(_debug, OID_AUTO, mtx_spin, CTLFLAG_RD, NULL, "mtx spin debugging"); static struct lock_delay_config __read_mostly mtx_spin_delay; SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_base, CTLFLAG_RW, &mtx_spin_delay.base, 0, ""); SYSCTL_INT(_debug_mtx_spin, OID_AUTO, delay_max, CTLFLAG_RW, &mtx_spin_delay.max, 0, ""); LOCK_DELAY_SYSINIT_DEFAULT(mtx_spin_delay); /* * System-wide mutexes */ struct mtx blocked_lock; struct mtx Giant; void assert_mtx(const struct lock_object *lock, int what) { mtx_assert((const struct mtx *)lock, what); } void lock_mtx(struct lock_object *lock, uintptr_t how) { mtx_lock((struct mtx *)lock); } void lock_spin(struct lock_object *lock, uintptr_t how) { panic("spin locks can only use msleep_spin"); } uintptr_t unlock_mtx(struct lock_object *lock) { struct mtx *m; m = (struct mtx *)lock; mtx_assert(m, MA_OWNED | MA_NOTRECURSED); mtx_unlock(m); return (0); } uintptr_t unlock_spin(struct lock_object *lock) { panic("spin locks can only use msleep_spin"); } #ifdef KDTRACE_HOOKS int owner_mtx(const struct lock_object *lock, struct thread **owner) { const struct mtx *m = (const struct mtx *)lock; *owner = mtx_owner(m); return (mtx_unowned(m) == 0); } #endif /* * Function versions of the inlined __mtx_* macros. These are used by * modules and can also be called from assembly language if needed. */ void __mtx_lock_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid, v; - if (SCHEDULER_STOPPED()) - return; - m = mtxlock2mtx(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("mtx_lock() by idle thread %p on sleep mutex %s @ %s:%d", curthread, m->lock_object.lo_name, file, line)); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_lock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, ("mtx_lock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); tid = (uintptr_t)curthread; v = MTX_UNOWNED; if (!_mtx_obtain_lock_fetch(m, &v, tid)) _mtx_lock_sleep(m, v, tid, opts, file, line); else LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, m, 0, 0, file, line); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, (opts & ~MTX_RECURSE) | LOP_EXCLUSIVE, file, line); TD_LOCKS_INC(curthread); } void __mtx_unlock_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; - - if (SCHEDULER_STOPPED()) - return; m = mtxlock2mtx(c); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_unlock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, ("mtx_unlock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, line); mtx_assert(m, MA_OWNED); __mtx_unlock_sleep(c, opts, file, line); TD_LOCKS_DEC(curthread); } void __mtx_lock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; if (SCHEDULER_STOPPED()) return; m = mtxlock2mtx(c); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_lock_spin() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("mtx_lock_spin() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || (opts & MTX_RECURSE) != 0, ("mtx_lock_spin: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); opts &= ~MTX_RECURSE; WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); __mtx_lock_spin(m, curthread, opts, file, line); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); } int __mtx_trylock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; if (SCHEDULER_STOPPED()) return (1); m = mtxlock2mtx(c); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_trylock_spin() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("mtx_trylock_spin() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); KASSERT((opts & MTX_RECURSE) == 0, ("mtx_trylock_spin: unsupp. opt MTX_RECURSE on mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); if (__mtx_trylock_spin(m, curthread, opts, file, line)) { LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 1, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); return (1); } LOCK_LOG_TRY("LOCK", &m->lock_object, opts, 0, file, line); return (0); } void __mtx_unlock_spin_flags(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; if (SCHEDULER_STOPPED()) return; m = mtxlock2mtx(c); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_unlock_spin() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("mtx_unlock_spin() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); WITNESS_UNLOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); LOCK_LOG_LOCK("UNLOCK", &m->lock_object, opts, m->mtx_recurse, file, line); mtx_assert(m, MA_OWNED); __mtx_unlock_spin(m); } /* * The important part of mtx_trylock{,_flags}() * Tries to acquire lock `m.' If this function is called on a mutex that * is already owned, it will recursively acquire the lock. */ int _mtx_trylock_flags_(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; #ifdef LOCK_PROFILING uint64_t waittime = 0; int contested = 0; #endif int rval; if (SCHEDULER_STOPPED()) return (1); m = mtxlock2mtx(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("mtx_trylock() by idle thread %p on sleep mutex %s @ %s:%d", curthread, m->lock_object.lo_name, file, line)); KASSERT(m->mtx_lock != MTX_DESTROYED, ("mtx_trylock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_sleep, ("mtx_trylock() of spin mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m) && ((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || (opts & MTX_RECURSE) != 0)) { m->mtx_recurse++; atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); rval = 1; } else rval = _mtx_obtain_lock(m, (uintptr_t)curthread); opts &= ~MTX_RECURSE; LOCK_LOG_TRY("LOCK", &m->lock_object, opts, rval, file, line); if (rval) { WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE | LOP_TRYLOCK, file, line); TD_LOCKS_INC(curthread); if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, m, contested, waittime, file, line); } return (rval); } /* * __mtx_lock_sleep: the tougher part of acquiring an MTX_DEF lock. * * We call this if the lock is either contested (i.e. we need to go to * sleep waiting for it), or if we need to recurse on it. */ void __mtx_lock_sleep(volatile uintptr_t *c, uintptr_t v, uintptr_t tid, int opts, const char *file, int line) { struct mtx *m; struct turnstile *ts; #ifdef ADAPTIVE_MUTEXES volatile struct thread *owner; #endif #ifdef KTR int cont_logged = 0; #endif #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #if defined(ADAPTIVE_MUTEXES) || defined(KDTRACE_HOOKS) struct lock_delay_arg lda; #endif #ifdef KDTRACE_HOOKS u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif if (SCHEDULER_STOPPED()) return; #if defined(ADAPTIVE_MUTEXES) lock_delay_arg_init(&lda, &mtx_delay); #elif defined(KDTRACE_HOOKS) lock_delay_arg_init(&lda, NULL); #endif m = mtxlock2mtx(c); if (__predict_false(v == MTX_UNOWNED)) v = MTX_READ_VALUE(m); if (__predict_false(lv_mtx_owner(v) == (struct thread *)tid)) { KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0 || (opts & MTX_RECURSE) != 0, ("_mtx_lock_sleep: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); opts &= ~MTX_RECURSE; m->mtx_recurse++; atomic_set_ptr(&m->mtx_lock, MTX_RECURSED); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_sleep: %p recursing", m); return; } opts &= ~MTX_RECURSE; #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR4(KTR_LOCK, "_mtx_lock_sleep: %s contested (lock=%p) at %s:%d", m->lock_object.lo_name, (void *)m->mtx_lock, file, line); #ifdef KDTRACE_HOOKS all_time -= lockstat_nsecs(&m->lock_object); #endif for (;;) { if (v == MTX_UNOWNED) { if (_mtx_obtain_lock_fetch(m, &v, tid)) break; continue; } #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif #ifdef ADAPTIVE_MUTEXES /* * If the owner is running on another CPU, spin until the * owner stops running or the state of the lock changes. */ owner = lv_mtx_owner(v); if (TD_IS_RUNNING(owner)) { if (LOCK_LOG_TEST(&m->lock_object, 0)) CTR3(KTR_LOCK, "%s: spinning on %p held by %p", __func__, m, owner); KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "spinning", "lockname:\"%s\"", m->lock_object.lo_name); do { lock_delay(&lda); v = MTX_READ_VALUE(m); owner = lv_mtx_owner(v); } while (v != MTX_UNOWNED && TD_IS_RUNNING(owner)); KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "running"); continue; } #endif ts = turnstile_trywait(&m->lock_object); v = MTX_READ_VALUE(m); /* * Check if the lock has been released while spinning for * the turnstile chain lock. */ if (v == MTX_UNOWNED) { turnstile_cancel(ts); continue; } #ifdef ADAPTIVE_MUTEXES /* * The current lock owner might have started executing * on another CPU (or the lock could have changed * owners) while we were waiting on the turnstile * chain lock. If so, drop the turnstile lock and try * again. */ owner = lv_mtx_owner(v); if (TD_IS_RUNNING(owner)) { turnstile_cancel(ts); continue; } #endif /* * If the mutex isn't already contested and a failure occurs * setting the contested bit, the mutex was either released * or the state of the MTX_RECURSED bit changed. */ if ((v & MTX_CONTESTED) == 0 && !atomic_cmpset_ptr(&m->mtx_lock, v, v | MTX_CONTESTED)) { turnstile_cancel(ts); v = MTX_READ_VALUE(m); continue; } /* * We definitely must sleep for this lock. */ mtx_assert(m, MA_NOTOWNED); #ifdef KTR if (!cont_logged) { CTR6(KTR_CONTENTION, "contention: %p at %s:%d wants %s, taken by %s:%d", (void *)tid, file, line, m->lock_object.lo_name, WITNESS_FILE(&m->lock_object), WITNESS_LINE(&m->lock_object)); cont_logged = 1; } #endif /* * Block on the turnstile. */ #ifdef KDTRACE_HOOKS sleep_time -= lockstat_nsecs(&m->lock_object); #endif turnstile_wait(ts, mtx_owner(m), TS_EXCLUSIVE_QUEUE); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&m->lock_object); sleep_cnt++; #endif v = MTX_READ_VALUE(m); } #ifdef KDTRACE_HOOKS all_time += lockstat_nsecs(&m->lock_object); #endif #ifdef KTR if (cont_logged) { CTR4(KTR_CONTENTION, "contention end: %s acquired by %p at %s:%d", m->lock_object.lo_name, (void *)tid, file, line); } #endif LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(adaptive__acquire, m, contested, waittime, file, line); #ifdef KDTRACE_HOOKS if (sleep_time) LOCKSTAT_RECORD1(adaptive__block, m, sleep_time); /* * Only record the loops spinning and not sleeping. */ if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD1(adaptive__spin, m, all_time - sleep_time); #endif } static void _mtx_lock_spin_failed(struct mtx *m) { struct thread *td; td = mtx_owner(m); /* If the mutex is unlocked, try again. */ if (td == NULL) return; printf( "spin lock %p (%s) held by %p (tid %d) too long\n", m, m->lock_object.lo_name, td, td->td_tid); #ifdef WITNESS witness_display_spinlock(&m->lock_object, td, printf); #endif panic("spin lock held too long"); } #ifdef SMP /* * _mtx_lock_spin_cookie: the tougher part of acquiring an MTX_SPIN lock. * * This is only called if we need to actually spin for the lock. Recursion * is handled inline. */ void _mtx_lock_spin_cookie(volatile uintptr_t *c, uintptr_t v, uintptr_t tid, int opts, const char *file, int line) { struct mtx *m; struct lock_delay_arg lda; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif if (SCHEDULER_STOPPED()) return; lock_delay_arg_init(&lda, &mtx_spin_delay); m = mtxlock2mtx(c); if (__predict_false(v == MTX_UNOWNED)) v = MTX_READ_VALUE(m); if (__predict_false(v == tid)) { m->mtx_recurse++; return; } if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spinning", m); KTR_STATE1(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "spinning", "lockname:\"%s\"", m->lock_object.lo_name); #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&m->lock_object); #endif for (;;) { if (v == MTX_UNOWNED) { if (_mtx_obtain_lock_fetch(m, &v, tid)) break; continue; } /* Give interrupts a chance while we spin. */ spinlock_exit(); do { if (lda.spin_cnt < 10000000) { lock_delay(&lda); } else { lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } v = MTX_READ_VALUE(m); } while (v != MTX_UNOWNED); spinlock_enter(); } #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_lock_spin: %p spin done", m); KTR_STATE0(KTR_SCHED, "thread", sched_tdname((struct thread *)tid), "running"); #ifdef KDTRACE_HOOKS LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); if (spin_time != 0) LOCKSTAT_RECORD1(spin__spin, m, spin_time); #endif } #endif /* SMP */ void thread_lock_flags_(struct thread *td, int opts, const char *file, int line) { struct mtx *m; uintptr_t tid, v; struct lock_delay_arg lda; #ifdef LOCK_PROFILING int contested = 0; uint64_t waittime = 0; #endif #ifdef KDTRACE_HOOKS int64_t spin_time = 0; #endif tid = (uintptr_t)curthread; if (SCHEDULER_STOPPED()) { /* * Ensure that spinlock sections are balanced even when the * scheduler is stopped, since we may otherwise inadvertently * re-enable interrupts while dumping core. */ spinlock_enter(); return; } lock_delay_arg_init(&lda, &mtx_spin_delay); #ifdef KDTRACE_HOOKS spin_time -= lockstat_nsecs(&td->td_lock->lock_object); #endif for (;;) { retry: v = MTX_UNOWNED; spinlock_enter(); m = td->td_lock; KASSERT(m->mtx_lock != MTX_DESTROYED, ("thread_lock() of destroyed mutex @ %s:%d", file, line)); KASSERT(LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin, ("thread_lock() of sleep mutex %s @ %s:%d", m->lock_object.lo_name, file, line)); if (mtx_owned(m)) KASSERT((m->lock_object.lo_flags & LO_RECURSABLE) != 0, ("thread_lock: recursed on non-recursive mutex %s @ %s:%d\n", m->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&m->lock_object, opts | LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); for (;;) { if (_mtx_obtain_lock_fetch(m, &v, tid)) break; if (v == MTX_UNOWNED) continue; if (v == tid) { m->mtx_recurse++; break; } #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&m->lock_object, &contested, &waittime); /* Give interrupts a chance while we spin. */ spinlock_exit(); do { if (lda.spin_cnt < 10000000) { lock_delay(&lda); } else { lda.spin_cnt++; if (lda.spin_cnt < 60000000 || kdb_active || panicstr != NULL) DELAY(1); else _mtx_lock_spin_failed(m); cpu_spinwait(); } if (m != td->td_lock) goto retry; v = MTX_READ_VALUE(m); } while (v != MTX_UNOWNED); spinlock_enter(); } if (m == td->td_lock) break; __mtx_unlock_spin(m); /* does spinlock_exit() */ } #ifdef KDTRACE_HOOKS spin_time += lockstat_nsecs(&m->lock_object); #endif if (m->mtx_recurse == 0) LOCKSTAT_PROFILE_OBTAIN_LOCK_SUCCESS(spin__acquire, m, contested, waittime, file, line); LOCK_LOG_LOCK("LOCK", &m->lock_object, opts, m->mtx_recurse, file, line); WITNESS_LOCK(&m->lock_object, opts | LOP_EXCLUSIVE, file, line); #ifdef KDTRACE_HOOKS if (spin_time != 0) LOCKSTAT_RECORD1(thread__spin, m, spin_time); #endif } struct mtx * thread_lock_block(struct thread *td) { struct mtx *lock; THREAD_LOCK_ASSERT(td, MA_OWNED); lock = td->td_lock; td->td_lock = &blocked_lock; mtx_unlock_spin(lock); return (lock); } void thread_lock_unblock(struct thread *td, struct mtx *new) { mtx_assert(new, MA_OWNED); MPASS(td->td_lock == &blocked_lock); atomic_store_rel_ptr((volatile void *)&td->td_lock, (uintptr_t)new); } void thread_lock_set(struct thread *td, struct mtx *new) { struct mtx *lock; mtx_assert(new, MA_OWNED); THREAD_LOCK_ASSERT(td, MA_OWNED); lock = td->td_lock; td->td_lock = new; mtx_unlock_spin(lock); } /* * __mtx_unlock_sleep: the tougher part of releasing an MTX_DEF lock. * * We are only called here if the lock is recursed, contested (i.e. we * need to wake up a blocked thread) or lockstat probe is active. */ void __mtx_unlock_sleep(volatile uintptr_t *c, int opts, const char *file, int line) { struct mtx *m; struct turnstile *ts; uintptr_t tid, v; if (SCHEDULER_STOPPED()) return; tid = (uintptr_t)curthread; m = mtxlock2mtx(c); v = MTX_READ_VALUE(m); if (v & MTX_RECURSED) { if (--(m->mtx_recurse) == 0) atomic_clear_ptr(&m->mtx_lock, MTX_RECURSED); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p unrecurse", m); return; } LOCKSTAT_PROFILE_RELEASE_LOCK(adaptive__release, m); if (v == tid && _mtx_release_lock(m, tid)) return; /* * We have to lock the chain before the turnstile so this turnstile * can be removed from the hash list if it is empty. */ turnstile_chain_lock(&m->lock_object); ts = turnstile_lookup(&m->lock_object); if (LOCK_LOG_TEST(&m->lock_object, opts)) CTR1(KTR_LOCK, "_mtx_unlock_sleep: %p contested", m); MPASS(ts != NULL); turnstile_broadcast(ts, TS_EXCLUSIVE_QUEUE); _mtx_release_lock_quick(m); /* * This turnstile is now no longer associated with the mutex. We can * unlock the chain lock so a new turnstile may take it's place. */ turnstile_unpend(ts, TS_EXCLUSIVE_LOCK); turnstile_chain_unlock(&m->lock_object); } /* * All the unlocking of MTX_SPIN locks is done inline. * See the __mtx_unlock_spin() macro for the details. */ /* * The backing function for the INVARIANTS-enabled mtx_assert() */ #ifdef INVARIANT_SUPPORT void __mtx_assert(const volatile uintptr_t *c, int what, const char *file, int line) { const struct mtx *m; if (panicstr != NULL || dumping || SCHEDULER_STOPPED()) return; m = mtxlock2mtx(c); switch (what) { case MA_OWNED: case MA_OWNED | MA_RECURSED: case MA_OWNED | MA_NOTRECURSED: if (!mtx_owned(m)) panic("mutex %s not owned at %s:%d", m->lock_object.lo_name, file, line); if (mtx_recursed(m)) { if ((what & MA_NOTRECURSED) != 0) panic("mutex %s recursed at %s:%d", m->lock_object.lo_name, file, line); } else if ((what & MA_RECURSED) != 0) { panic("mutex %s unrecursed at %s:%d", m->lock_object.lo_name, file, line); } break; case MA_NOTOWNED: if (mtx_owned(m)) panic("mutex %s owned at %s:%d", m->lock_object.lo_name, file, line); break; default: panic("unknown mtx_assert at %s:%d", file, line); } } #endif /* * General init routine used by the MTX_SYSINIT() macro. */ void mtx_sysinit(void *arg) { struct mtx_args *margs = arg; mtx_init((struct mtx *)margs->ma_mtx, margs->ma_desc, NULL, margs->ma_opts); } /* * Mutex initialization routine; initialize lock `m' of type contained in * `opts' with options contained in `opts' and name `name.' The optional * lock type `type' is used as a general lock category name for use with * witness. */ void _mtx_init(volatile uintptr_t *c, const char *name, const char *type, int opts) { struct mtx *m; struct lock_class *class; int flags; m = mtxlock2mtx(c); MPASS((opts & ~(MTX_SPIN | MTX_QUIET | MTX_RECURSE | MTX_NOWITNESS | MTX_DUPOK | MTX_NOPROFILE | MTX_NEW)) == 0); ASSERT_ATOMIC_LOAD_PTR(m->mtx_lock, ("%s: mtx_lock not aligned for %s: %p", __func__, name, &m->mtx_lock)); /* Determine lock class and lock flags. */ if (opts & MTX_SPIN) class = &lock_class_mtx_spin; else class = &lock_class_mtx_sleep; flags = 0; if (opts & MTX_QUIET) flags |= LO_QUIET; if (opts & MTX_RECURSE) flags |= LO_RECURSABLE; if ((opts & MTX_NOWITNESS) == 0) flags |= LO_WITNESS; if (opts & MTX_DUPOK) flags |= LO_DUPOK; if (opts & MTX_NOPROFILE) flags |= LO_NOPROFILE; if (opts & MTX_NEW) flags |= LO_NEW; /* Initialize mutex. */ lock_init(&m->lock_object, class, name, type, flags); m->mtx_lock = MTX_UNOWNED; m->mtx_recurse = 0; } /* * Remove lock `m' from all_mtx queue. We don't allow MTX_QUIET to be * passed in as a flag here because if the corresponding mtx_init() was * called with MTX_QUIET set, then it will already be set in the mutex's * flags. */ void _mtx_destroy(volatile uintptr_t *c) { struct mtx *m; m = mtxlock2mtx(c); if (!mtx_owned(m)) MPASS(mtx_unowned(m)); else { MPASS((m->mtx_lock & (MTX_RECURSED|MTX_CONTESTED)) == 0); /* Perform the non-mtx related part of mtx_unlock_spin(). */ if (LOCK_CLASS(&m->lock_object) == &lock_class_mtx_spin) spinlock_exit(); else TD_LOCKS_DEC(curthread); lock_profile_release_lock(&m->lock_object); /* Tell witness this isn't locked to make it happy. */ WITNESS_UNLOCK(&m->lock_object, LOP_EXCLUSIVE, __FILE__, __LINE__); } m->mtx_lock = MTX_DESTROYED; lock_destroy(&m->lock_object); } /* * Intialize the mutex code and system mutexes. This is called from the MD * startup code prior to mi_startup(). The per-CPU data space needs to be * setup before this is called. */ void mutex_init(void) { /* Setup turnstiles so that sleep mutexes work. */ init_turnstiles(); /* * Initialize mutexes. */ mtx_init(&Giant, "Giant", NULL, MTX_DEF | MTX_RECURSE); mtx_init(&blocked_lock, "blocked lock", NULL, MTX_SPIN); blocked_lock.mtx_lock = 0xdeadc0de; /* Always blocked. */ mtx_init(&proc0.p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK); mtx_init(&proc0.p_slock, "process slock", NULL, MTX_SPIN); mtx_init(&proc0.p_statmtx, "pstatl", NULL, MTX_SPIN); mtx_init(&proc0.p_itimmtx, "pitiml", NULL, MTX_SPIN); mtx_init(&proc0.p_profmtx, "pprofl", NULL, MTX_SPIN); mtx_init(&devmtx, "cdev", NULL, MTX_DEF); mtx_lock(&Giant); } #ifdef DDB void db_show_mtx(const struct lock_object *lock) { struct thread *td; const struct mtx *m; m = (const struct mtx *)lock; db_printf(" flags: {"); if (LOCK_CLASS(lock) == &lock_class_mtx_spin) db_printf("SPIN"); else db_printf("DEF"); if (m->lock_object.lo_flags & LO_RECURSABLE) db_printf(", RECURSE"); if (m->lock_object.lo_flags & LO_DUPOK) db_printf(", DUPOK"); db_printf("}\n"); db_printf(" state: {"); if (mtx_unowned(m)) db_printf("UNOWNED"); else if (mtx_destroyed(m)) db_printf("DESTROYED"); else { db_printf("OWNED"); if (m->mtx_lock & MTX_CONTESTED) db_printf(", CONTESTED"); if (m->mtx_lock & MTX_RECURSED) db_printf(", RECURSED"); } db_printf("}\n"); if (!mtx_unowned(m) && !mtx_destroyed(m)) { td = mtx_owner(m); db_printf(" owner: %p (tid %d, pid %d, \"%s\")\n", td, td->td_tid, td->td_proc->p_pid, td->td_name); if (mtx_recursed(m)) db_printf(" recursed: %d\n", m->mtx_recurse); } } #endif Index: stable/11/sys/kern/kern_rwlock.c =================================================================== --- stable/11/sys/kern/kern_rwlock.c (revision 315385) +++ stable/11/sys/kern/kern_rwlock.c (revision 315386) @@ -1,1385 +1,1379 @@ /*- * Copyright (c) 2006 John Baldwin * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Machine independent bits of reader/writer lock implementation. */ #include __FBSDID("$FreeBSD$"); #include "opt_ddb.h" #include "opt_hwpmc_hooks.h" #include "opt_no_adaptive_rwlocks.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) && !defined(NO_ADAPTIVE_RWLOCKS) #define ADAPTIVE_RWLOCKS #endif #ifdef HWPMC_HOOKS #include PMC_SOFT_DECLARE( , , lock, failed); #endif /* * Return the rwlock address when the lock cookie address is provided. * This functionality assumes that struct rwlock* have a member named rw_lock. */ #define rwlock2rw(c) (__containerof(c, struct rwlock, rw_lock)) #ifdef DDB #include static void db_show_rwlock(const struct lock_object *lock); #endif static void assert_rw(const struct lock_object *lock, int what); static void lock_rw(struct lock_object *lock, uintptr_t how); #ifdef KDTRACE_HOOKS static int owner_rw(const struct lock_object *lock, struct thread **owner); #endif static uintptr_t unlock_rw(struct lock_object *lock); struct lock_class lock_class_rw = { .lc_name = "rw", .lc_flags = LC_SLEEPLOCK | LC_RECURSABLE | LC_UPGRADABLE, .lc_assert = assert_rw, #ifdef DDB .lc_ddb_show = db_show_rwlock, #endif .lc_lock = lock_rw, .lc_unlock = unlock_rw, #ifdef KDTRACE_HOOKS .lc_owner = owner_rw, #endif }; #ifdef ADAPTIVE_RWLOCKS static int rowner_retries = 10; static int rowner_loops = 10000; static SYSCTL_NODE(_debug, OID_AUTO, rwlock, CTLFLAG_RD, NULL, "rwlock debugging"); SYSCTL_INT(_debug_rwlock, OID_AUTO, retry, CTLFLAG_RW, &rowner_retries, 0, ""); SYSCTL_INT(_debug_rwlock, OID_AUTO, loops, CTLFLAG_RW, &rowner_loops, 0, ""); static struct lock_delay_config __read_mostly rw_delay; SYSCTL_INT(_debug_rwlock, OID_AUTO, delay_base, CTLFLAG_RW, &rw_delay.base, 0, ""); SYSCTL_INT(_debug_rwlock, OID_AUTO, delay_max, CTLFLAG_RW, &rw_delay.max, 0, ""); LOCK_DELAY_SYSINIT_DEFAULT(rw_delay); #endif /* * Return a pointer to the owning thread if the lock is write-locked or * NULL if the lock is unlocked or read-locked. */ #define lv_rw_wowner(v) \ ((v) & RW_LOCK_READ ? NULL : \ (struct thread *)RW_OWNER((v))) #define rw_wowner(rw) lv_rw_wowner(RW_READ_VALUE(rw)) /* * Returns if a write owner is recursed. Write ownership is not assured * here and should be previously checked. */ #define rw_recursed(rw) ((rw)->rw_recurse != 0) /* * Return true if curthread helds the lock. */ #define rw_wlocked(rw) (rw_wowner((rw)) == curthread) /* * Return a pointer to the owning thread for this lock who should receive * any priority lent by threads that block on this lock. Currently this * is identical to rw_wowner(). */ #define rw_owner(rw) rw_wowner(rw) #ifndef INVARIANTS #define __rw_assert(c, what, file, line) #endif void assert_rw(const struct lock_object *lock, int what) { rw_assert((const struct rwlock *)lock, what); } void lock_rw(struct lock_object *lock, uintptr_t how) { struct rwlock *rw; rw = (struct rwlock *)lock; if (how) rw_rlock(rw); else rw_wlock(rw); } uintptr_t unlock_rw(struct lock_object *lock) { struct rwlock *rw; rw = (struct rwlock *)lock; rw_assert(rw, RA_LOCKED | LA_NOTRECURSED); if (rw->rw_lock & RW_LOCK_READ) { rw_runlock(rw); return (1); } else { rw_wunlock(rw); return (0); } } #ifdef KDTRACE_HOOKS int owner_rw(const struct lock_object *lock, struct thread **owner) { const struct rwlock *rw = (const struct rwlock *)lock; uintptr_t x = rw->rw_lock; *owner = rw_wowner(rw); return ((x & RW_LOCK_READ) != 0 ? (RW_READERS(x) != 0) : (*owner != NULL)); } #endif void _rw_init_flags(volatile uintptr_t *c, const char *name, int opts) { struct rwlock *rw; int flags; rw = rwlock2rw(c); MPASS((opts & ~(RW_DUPOK | RW_NOPROFILE | RW_NOWITNESS | RW_QUIET | RW_RECURSE | RW_NEW)) == 0); ASSERT_ATOMIC_LOAD_PTR(rw->rw_lock, ("%s: rw_lock not aligned for %s: %p", __func__, name, &rw->rw_lock)); flags = LO_UPGRADABLE; if (opts & RW_DUPOK) flags |= LO_DUPOK; if (opts & RW_NOPROFILE) flags |= LO_NOPROFILE; if (!(opts & RW_NOWITNESS)) flags |= LO_WITNESS; if (opts & RW_RECURSE) flags |= LO_RECURSABLE; if (opts & RW_QUIET) flags |= LO_QUIET; if (opts & RW_NEW) flags |= LO_NEW; lock_init(&rw->lock_object, &lock_class_rw, name, NULL, flags); rw->rw_lock = RW_UNLOCKED; rw->rw_recurse = 0; } void _rw_destroy(volatile uintptr_t *c) { struct rwlock *rw; rw = rwlock2rw(c); KASSERT(rw->rw_lock == RW_UNLOCKED, ("rw lock %p not unlocked", rw)); KASSERT(rw->rw_recurse == 0, ("rw lock %p still recursed", rw)); rw->rw_lock = RW_DESTROYED; lock_destroy(&rw->lock_object); } void rw_sysinit(void *arg) { struct rw_args *args = arg; rw_init((struct rwlock *)args->ra_rw, args->ra_desc); } void rw_sysinit_flags(void *arg) { struct rw_args_flags *args = arg; rw_init_flags((struct rwlock *)args->ra_rw, args->ra_desc, args->ra_flags); } int _rw_wowned(const volatile uintptr_t *c) { return (rw_wowner(rwlock2rw(c)) == curthread); } void _rw_wlock_cookie(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; uintptr_t tid, v; - if (SCHEDULER_STOPPED()) - return; - rw = rwlock2rw(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("rw_wlock() by idle thread %p on rwlock %s @ %s:%d", curthread, rw->lock_object.lo_name, file, line)); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_wlock() of destroyed rwlock @ %s:%d", file, line)); WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); tid = (uintptr_t)curthread; v = RW_UNLOCKED; if (!_rw_write_lock_fetch(rw, &v, tid)) _rw_wlock_hard(rw, v, tid, file, line); else LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, 0, 0, file, line, LOCKSTAT_WRITER); LOCK_LOG_LOCK("WLOCK", &rw->lock_object, 0, rw->rw_recurse, file, line); WITNESS_LOCK(&rw->lock_object, LOP_EXCLUSIVE, file, line); TD_LOCKS_INC(curthread); } int __rw_try_wlock(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; int rval; if (SCHEDULER_STOPPED()) return (1); rw = rwlock2rw(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("rw_try_wlock() by idle thread %p on rwlock %s @ %s:%d", curthread, rw->lock_object.lo_name, file, line)); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_try_wlock() of destroyed rwlock @ %s:%d", file, line)); if (rw_wlocked(rw) && (rw->lock_object.lo_flags & LO_RECURSABLE) != 0) { rw->rw_recurse++; atomic_set_ptr(&rw->rw_lock, RW_LOCK_WRITER_RECURSED); rval = 1; } else rval = atomic_cmpset_acq_ptr(&rw->rw_lock, RW_UNLOCKED, (uintptr_t)curthread); LOCK_LOG_TRY("WLOCK", &rw->lock_object, 0, rval, file, line); if (rval) { WITNESS_LOCK(&rw->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file, line); if (!rw_recursed(rw)) LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, 0, 0, file, line, LOCKSTAT_WRITER); TD_LOCKS_INC(curthread); } return (rval); } void _rw_wunlock_cookie(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; - - if (SCHEDULER_STOPPED()) - return; rw = rwlock2rw(c); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_wunlock() of destroyed rwlock @ %s:%d", file, line)); __rw_assert(c, RA_WLOCKED, file, line); WITNESS_UNLOCK(&rw->lock_object, LOP_EXCLUSIVE, file, line); LOCK_LOG_LOCK("WUNLOCK", &rw->lock_object, 0, rw->rw_recurse, file, line); _rw_wunlock_hard(rw, (uintptr_t)curthread, file, line); TD_LOCKS_DEC(curthread); } /* * Determines whether a new reader can acquire a lock. Succeeds if the * reader already owns a read lock and the lock is locked for read to * prevent deadlock from reader recursion. Also succeeds if the lock * is unlocked and has no writer waiters or spinners. Failing otherwise * prioritizes writers before readers. */ #define RW_CAN_READ(td, _rw) \ (((td)->td_rw_rlocks && (_rw) & RW_LOCK_READ) || ((_rw) & \ (RW_LOCK_READ | RW_LOCK_WRITE_WAITERS | RW_LOCK_WRITE_SPINNER)) == \ RW_LOCK_READ) static bool __always_inline __rw_rlock_try(struct rwlock *rw, struct thread *td, uintptr_t *vp, const char *file, int line) { /* * Handle the easy case. If no other thread has a write * lock, then try to bump up the count of read locks. Note * that we have to preserve the current state of the * RW_LOCK_WRITE_WAITERS flag. If we fail to acquire a * read lock, then rw_lock must have changed, so restart * the loop. Note that this handles the case of a * completely unlocked rwlock since such a lock is encoded * as a read lock with no waiters. */ while (RW_CAN_READ(td, *vp)) { if (atomic_fcmpset_acq_ptr(&rw->rw_lock, vp, *vp + RW_ONE_READER)) { if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR4(KTR_LOCK, "%s: %p succeed %p -> %p", __func__, rw, (void *)*vp, (void *)(*vp + RW_ONE_READER)); td->td_rw_rlocks++; return (true); } } return (false); } static void __noinline __rw_rlock_hard(volatile uintptr_t *c, struct thread *td, uintptr_t v, const char *file, int line) { struct rwlock *rw; struct turnstile *ts; #ifdef ADAPTIVE_RWLOCKS volatile struct thread *owner; int spintries = 0; int i; #endif #ifdef LOCK_PROFILING uint64_t waittime = 0; int contested = 0; #endif #if defined(ADAPTIVE_RWLOCKS) || defined(KDTRACE_HOOKS) struct lock_delay_arg lda; #endif #ifdef KDTRACE_HOOKS uintptr_t state; u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif if (SCHEDULER_STOPPED()) return; #if defined(ADAPTIVE_RWLOCKS) lock_delay_arg_init(&lda, &rw_delay); #elif defined(KDTRACE_HOOKS) lock_delay_arg_init(&lda, NULL); #endif rw = rwlock2rw(c); #ifdef KDTRACE_HOOKS all_time -= lockstat_nsecs(&rw->lock_object); #endif #ifdef KDTRACE_HOOKS state = v; #endif for (;;) { if (__rw_rlock_try(rw, td, &v, file, line)) break; #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&rw->lock_object, &contested, &waittime); #ifdef ADAPTIVE_RWLOCKS /* * If the owner is running on another CPU, spin until * the owner stops running or the state of the lock * changes. */ if ((v & RW_LOCK_READ) == 0) { owner = (struct thread *)RW_OWNER(v); if (TD_IS_RUNNING(owner)) { if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR3(KTR_LOCK, "%s: spinning on %p held by %p", __func__, rw, owner); KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", rw->lock_object.lo_name); do { lock_delay(&lda); v = RW_READ_VALUE(rw); owner = lv_rw_wowner(v); } while (owner != NULL && TD_IS_RUNNING(owner)); KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); continue; } } else if (spintries < rowner_retries) { spintries++; KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", rw->lock_object.lo_name); for (i = 0; i < rowner_loops; i++) { v = RW_READ_VALUE(rw); if ((v & RW_LOCK_READ) == 0 || RW_CAN_READ(td, v)) break; cpu_spinwait(); } v = RW_READ_VALUE(rw); #ifdef KDTRACE_HOOKS lda.spin_cnt += rowner_loops - i; #endif KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); if (i != rowner_loops) continue; } #endif /* * Okay, now it's the hard case. Some other thread already * has a write lock or there are write waiters present, * acquire the turnstile lock so we can begin the process * of blocking. */ ts = turnstile_trywait(&rw->lock_object); /* * The lock might have been released while we spun, so * recheck its state and restart the loop if needed. */ v = RW_READ_VALUE(rw); if (RW_CAN_READ(td, v)) { turnstile_cancel(ts); continue; } #ifdef ADAPTIVE_RWLOCKS /* * The current lock owner might have started executing * on another CPU (or the lock could have changed * owners) while we were waiting on the turnstile * chain lock. If so, drop the turnstile lock and try * again. */ if ((v & RW_LOCK_READ) == 0) { owner = (struct thread *)RW_OWNER(v); if (TD_IS_RUNNING(owner)) { turnstile_cancel(ts); continue; } } #endif /* * The lock is held in write mode or it already has waiters. */ MPASS(!RW_CAN_READ(td, v)); /* * If the RW_LOCK_READ_WAITERS flag is already set, then * we can go ahead and block. If it is not set then try * to set it. If we fail to set it drop the turnstile * lock and restart the loop. */ if (!(v & RW_LOCK_READ_WAITERS)) { if (!atomic_cmpset_ptr(&rw->rw_lock, v, v | RW_LOCK_READ_WAITERS)) { turnstile_cancel(ts); v = RW_READ_VALUE(rw); continue; } if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p set read waiters flag", __func__, rw); } /* * We were unable to acquire the lock and the read waiters * flag is set, so we must block on the turnstile. */ if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p blocking on turnstile", __func__, rw); #ifdef KDTRACE_HOOKS sleep_time -= lockstat_nsecs(&rw->lock_object); #endif turnstile_wait(ts, rw_owner(rw), TS_SHARED_QUEUE); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&rw->lock_object); sleep_cnt++; #endif if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p resuming from turnstile", __func__, rw); v = RW_READ_VALUE(rw); } #ifdef KDTRACE_HOOKS all_time += lockstat_nsecs(&rw->lock_object); if (sleep_time) LOCKSTAT_RECORD4(rw__block, rw, sleep_time, LOCKSTAT_READER, (state & RW_LOCK_READ) == 0, (state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state)); /* Record only the loops spinning and not sleeping. */ if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(rw__spin, rw, all_time - sleep_time, LOCKSTAT_READER, (state & RW_LOCK_READ) == 0, (state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state)); #endif /* * TODO: acquire "owner of record" here. Here be turnstile dragons * however. turnstiles don't like owners changing between calls to * turnstile_wait() currently. */ LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, contested, waittime, file, line, LOCKSTAT_READER); } void __rw_rlock(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; struct thread *td; uintptr_t v; td = curthread; rw = rwlock2rw(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(td), ("rw_rlock() by idle thread %p on rwlock %s @ %s:%d", td, rw->lock_object.lo_name, file, line)); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_rlock() of destroyed rwlock @ %s:%d", file, line)); KASSERT(rw_wowner(rw) != td, ("rw_rlock: wlock already held for %s @ %s:%d", rw->lock_object.lo_name, file, line)); WITNESS_CHECKORDER(&rw->lock_object, LOP_NEWORDER, file, line, NULL); v = RW_READ_VALUE(rw); if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(rw__acquire) || !__rw_rlock_try(rw, td, &v, file, line))) __rw_rlock_hard(c, td, v, file, line); LOCK_LOG_LOCK("RLOCK", &rw->lock_object, 0, 0, file, line); WITNESS_LOCK(&rw->lock_object, 0, file, line); TD_LOCKS_INC(curthread); } int __rw_try_rlock(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; uintptr_t x; if (SCHEDULER_STOPPED()) return (1); rw = rwlock2rw(c); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("rw_try_rlock() by idle thread %p on rwlock %s @ %s:%d", curthread, rw->lock_object.lo_name, file, line)); for (;;) { x = rw->rw_lock; KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_try_rlock() of destroyed rwlock @ %s:%d", file, line)); if (!(x & RW_LOCK_READ)) break; if (atomic_cmpset_acq_ptr(&rw->rw_lock, x, x + RW_ONE_READER)) { LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 1, file, line); WITNESS_LOCK(&rw->lock_object, LOP_TRYLOCK, file, line); LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, 0, 0, file, line, LOCKSTAT_READER); TD_LOCKS_INC(curthread); curthread->td_rw_rlocks++; return (1); } } LOCK_LOG_TRY("RLOCK", &rw->lock_object, 0, 0, file, line); return (0); } static bool __always_inline __rw_runlock_try(struct rwlock *rw, struct thread *td, uintptr_t *vp) { for (;;) { /* * See if there is more than one read lock held. If so, * just drop one and return. */ if (RW_READERS(*vp) > 1) { if (atomic_fcmpset_rel_ptr(&rw->rw_lock, vp, *vp - RW_ONE_READER)) { if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR4(KTR_LOCK, "%s: %p succeeded %p -> %p", __func__, rw, (void *)*vp, (void *)(*vp - RW_ONE_READER)); td->td_rw_rlocks--; return (true); } continue; } /* * If there aren't any waiters for a write lock, then try * to drop it quickly. */ if (!(*vp & RW_LOCK_WAITERS)) { MPASS((*vp & ~RW_LOCK_WRITE_SPINNER) == RW_READERS_LOCK(1)); if (atomic_fcmpset_rel_ptr(&rw->rw_lock, vp, RW_UNLOCKED)) { if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p last succeeded", __func__, rw); td->td_rw_rlocks--; return (true); } continue; } break; } return (false); } static void __noinline __rw_runlock_hard(volatile uintptr_t *c, struct thread *td, uintptr_t v, const char *file, int line) { struct rwlock *rw; struct turnstile *ts; uintptr_t x, queue; if (SCHEDULER_STOPPED()) return; rw = rwlock2rw(c); for (;;) { if (__rw_runlock_try(rw, td, &v)) break; /* * Ok, we know we have waiters and we think we are the * last reader, so grab the turnstile lock. */ turnstile_chain_lock(&rw->lock_object); v = rw->rw_lock & (RW_LOCK_WAITERS | RW_LOCK_WRITE_SPINNER); MPASS(v & RW_LOCK_WAITERS); /* * Try to drop our lock leaving the lock in a unlocked * state. * * If you wanted to do explicit lock handoff you'd have to * do it here. You'd also want to use turnstile_signal() * and you'd have to handle the race where a higher * priority thread blocks on the write lock before the * thread you wakeup actually runs and have the new thread * "steal" the lock. For now it's a lot simpler to just * wakeup all of the waiters. * * As above, if we fail, then another thread might have * acquired a read lock, so drop the turnstile lock and * restart. */ x = RW_UNLOCKED; if (v & RW_LOCK_WRITE_WAITERS) { queue = TS_EXCLUSIVE_QUEUE; x |= (v & RW_LOCK_READ_WAITERS); } else queue = TS_SHARED_QUEUE; if (!atomic_cmpset_rel_ptr(&rw->rw_lock, RW_READERS_LOCK(1) | v, x)) { turnstile_chain_unlock(&rw->lock_object); x = RW_READ_VALUE(rw); continue; } if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p last succeeded with waiters", __func__, rw); /* * Ok. The lock is released and all that's left is to * wake up the waiters. Note that the lock might not be * free anymore, but in that case the writers will just * block again if they run before the new lock holder(s) * release the lock. */ ts = turnstile_lookup(&rw->lock_object); MPASS(ts != NULL); turnstile_broadcast(ts, queue); turnstile_unpend(ts, TS_SHARED_LOCK); turnstile_chain_unlock(&rw->lock_object); td->td_rw_rlocks--; break; } LOCKSTAT_PROFILE_RELEASE_RWLOCK(rw__release, rw, LOCKSTAT_READER); } void _rw_runlock_cookie(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; struct thread *td; uintptr_t v; rw = rwlock2rw(c); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_runlock() of destroyed rwlock @ %s:%d", file, line)); __rw_assert(c, RA_RLOCKED, file, line); WITNESS_UNLOCK(&rw->lock_object, 0, file, line); LOCK_LOG_LOCK("RUNLOCK", &rw->lock_object, 0, 0, file, line); td = curthread; v = RW_READ_VALUE(rw); if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(rw__release) || !__rw_runlock_try(rw, td, &v))) __rw_runlock_hard(c, td, v, file, line); TD_LOCKS_DEC(curthread); } /* * This function is called when we are unable to obtain a write lock on the * first try. This means that at least one other thread holds either a * read or write lock. */ void __rw_wlock_hard(volatile uintptr_t *c, uintptr_t v, uintptr_t tid, const char *file, int line) { struct rwlock *rw; struct turnstile *ts; #ifdef ADAPTIVE_RWLOCKS volatile struct thread *owner; int spintries = 0; int i; #endif uintptr_t x; #ifdef LOCK_PROFILING uint64_t waittime = 0; int contested = 0; #endif #if defined(ADAPTIVE_RWLOCKS) || defined(KDTRACE_HOOKS) struct lock_delay_arg lda; #endif #ifdef KDTRACE_HOOKS uintptr_t state; u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif if (SCHEDULER_STOPPED()) return; #if defined(ADAPTIVE_RWLOCKS) lock_delay_arg_init(&lda, &rw_delay); #elif defined(KDTRACE_HOOKS) lock_delay_arg_init(&lda, NULL); #endif rw = rwlock2rw(c); if (__predict_false(v == RW_UNLOCKED)) v = RW_READ_VALUE(rw); if (__predict_false(lv_rw_wowner(v) == (struct thread *)tid)) { KASSERT(rw->lock_object.lo_flags & LO_RECURSABLE, ("%s: recursing but non-recursive rw %s @ %s:%d\n", __func__, rw->lock_object.lo_name, file, line)); rw->rw_recurse++; atomic_set_ptr(&rw->rw_lock, RW_LOCK_WRITER_RECURSED); if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p recursing", __func__, rw); return; } if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR5(KTR_LOCK, "%s: %s contested (lock=%p) at %s:%d", __func__, rw->lock_object.lo_name, (void *)rw->rw_lock, file, line); #ifdef KDTRACE_HOOKS all_time -= lockstat_nsecs(&rw->lock_object); state = v; #endif for (;;) { if (v == RW_UNLOCKED) { if (_rw_write_lock_fetch(rw, &v, tid)) break; continue; } #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&rw->lock_object, &contested, &waittime); #ifdef ADAPTIVE_RWLOCKS /* * If the lock is write locked and the owner is * running on another CPU, spin until the owner stops * running or the state of the lock changes. */ owner = lv_rw_wowner(v); if (!(v & RW_LOCK_READ) && TD_IS_RUNNING(owner)) { if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR3(KTR_LOCK, "%s: spinning on %p held by %p", __func__, rw, owner); KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", rw->lock_object.lo_name); do { lock_delay(&lda); v = RW_READ_VALUE(rw); owner = lv_rw_wowner(v); } while (owner != NULL && TD_IS_RUNNING(owner)); KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); continue; } if ((v & RW_LOCK_READ) && RW_READERS(v) && spintries < rowner_retries) { if (!(v & RW_LOCK_WRITE_SPINNER)) { if (!atomic_cmpset_ptr(&rw->rw_lock, v, v | RW_LOCK_WRITE_SPINNER)) { v = RW_READ_VALUE(rw); continue; } } spintries++; KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", rw->lock_object.lo_name); for (i = 0; i < rowner_loops; i++) { if ((rw->rw_lock & RW_LOCK_WRITE_SPINNER) == 0) break; cpu_spinwait(); } KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); v = RW_READ_VALUE(rw); #ifdef KDTRACE_HOOKS lda.spin_cnt += rowner_loops - i; #endif if (i != rowner_loops) continue; } #endif ts = turnstile_trywait(&rw->lock_object); v = RW_READ_VALUE(rw); #ifdef ADAPTIVE_RWLOCKS /* * The current lock owner might have started executing * on another CPU (or the lock could have changed * owners) while we were waiting on the turnstile * chain lock. If so, drop the turnstile lock and try * again. */ if (!(v & RW_LOCK_READ)) { owner = (struct thread *)RW_OWNER(v); if (TD_IS_RUNNING(owner)) { turnstile_cancel(ts); continue; } } #endif /* * Check for the waiters flags about this rwlock. * If the lock was released, without maintain any pending * waiters queue, simply try to acquire it. * If a pending waiters queue is present, claim the lock * ownership and maintain the pending queue. */ x = v & (RW_LOCK_WAITERS | RW_LOCK_WRITE_SPINNER); if ((v & ~x) == RW_UNLOCKED) { x &= ~RW_LOCK_WRITE_SPINNER; if (atomic_cmpset_acq_ptr(&rw->rw_lock, v, tid | x)) { if (x) turnstile_claim(ts); else turnstile_cancel(ts); break; } turnstile_cancel(ts); v = RW_READ_VALUE(rw); continue; } /* * If the RW_LOCK_WRITE_WAITERS flag isn't set, then try to * set it. If we fail to set it, then loop back and try * again. */ if (!(v & RW_LOCK_WRITE_WAITERS)) { if (!atomic_cmpset_ptr(&rw->rw_lock, v, v | RW_LOCK_WRITE_WAITERS)) { turnstile_cancel(ts); v = RW_READ_VALUE(rw); continue; } if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p set write waiters flag", __func__, rw); } /* * We were unable to acquire the lock and the write waiters * flag is set, so we must block on the turnstile. */ if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p blocking on turnstile", __func__, rw); #ifdef KDTRACE_HOOKS sleep_time -= lockstat_nsecs(&rw->lock_object); #endif turnstile_wait(ts, rw_owner(rw), TS_EXCLUSIVE_QUEUE); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&rw->lock_object); sleep_cnt++; #endif if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p resuming from turnstile", __func__, rw); #ifdef ADAPTIVE_RWLOCKS spintries = 0; #endif v = RW_READ_VALUE(rw); } #ifdef KDTRACE_HOOKS all_time += lockstat_nsecs(&rw->lock_object); if (sleep_time) LOCKSTAT_RECORD4(rw__block, rw, sleep_time, LOCKSTAT_WRITER, (state & RW_LOCK_READ) == 0, (state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state)); /* Record only the loops spinning and not sleeping. */ if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(rw__spin, rw, all_time - sleep_time, LOCKSTAT_WRITER, (state & RW_LOCK_READ) == 0, (state & RW_LOCK_READ) == 0 ? 0 : RW_READERS(state)); #endif LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(rw__acquire, rw, contested, waittime, file, line, LOCKSTAT_WRITER); } /* * This function is called if lockstat is active or the first try at releasing * a write lock failed. The latter means that the lock is recursed or one of * the 2 waiter bits must be set indicating that at least one thread is waiting * on this lock. */ void __rw_wunlock_hard(volatile uintptr_t *c, uintptr_t tid, const char *file, int line) { struct rwlock *rw; struct turnstile *ts; uintptr_t v; int queue; if (SCHEDULER_STOPPED()) return; rw = rwlock2rw(c); v = RW_READ_VALUE(rw); if (v & RW_LOCK_WRITER_RECURSED) { if (--(rw->rw_recurse) == 0) atomic_clear_ptr(&rw->rw_lock, RW_LOCK_WRITER_RECURSED); if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p unrecursing", __func__, rw); return; } LOCKSTAT_PROFILE_RELEASE_RWLOCK(rw__release, rw, LOCKSTAT_WRITER); if (v == tid && _rw_write_unlock(rw, tid)) return; KASSERT(rw->rw_lock & (RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS), ("%s: neither of the waiter flags are set", __func__)); if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p contested", __func__, rw); turnstile_chain_lock(&rw->lock_object); ts = turnstile_lookup(&rw->lock_object); MPASS(ts != NULL); /* * Use the same algo as sx locks for now. Prefer waking up shared * waiters if we have any over writers. This is probably not ideal. * * 'v' is the value we are going to write back to rw_lock. If we * have waiters on both queues, we need to preserve the state of * the waiter flag for the queue we don't wake up. For now this is * hardcoded for the algorithm mentioned above. * * In the case of both readers and writers waiting we wakeup the * readers but leave the RW_LOCK_WRITE_WAITERS flag set. If a * new writer comes in before a reader it will claim the lock up * above. There is probably a potential priority inversion in * there that could be worked around either by waking both queues * of waiters or doing some complicated lock handoff gymnastics. */ v = RW_UNLOCKED; if (rw->rw_lock & RW_LOCK_WRITE_WAITERS) { queue = TS_EXCLUSIVE_QUEUE; v |= (rw->rw_lock & RW_LOCK_READ_WAITERS); } else queue = TS_SHARED_QUEUE; /* Wake up all waiters for the specific queue. */ if (LOCK_LOG_TEST(&rw->lock_object, 0)) CTR3(KTR_LOCK, "%s: %p waking up %s waiters", __func__, rw, queue == TS_SHARED_QUEUE ? "read" : "write"); turnstile_broadcast(ts, queue); atomic_store_rel_ptr(&rw->rw_lock, v); turnstile_unpend(ts, TS_EXCLUSIVE_LOCK); turnstile_chain_unlock(&rw->lock_object); } /* * Attempt to do a non-blocking upgrade from a read lock to a write * lock. This will only succeed if this thread holds a single read * lock. Returns true if the upgrade succeeded and false otherwise. */ int __rw_try_upgrade(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; uintptr_t v, x, tid; struct turnstile *ts; int success; if (SCHEDULER_STOPPED()) return (1); rw = rwlock2rw(c); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_try_upgrade() of destroyed rwlock @ %s:%d", file, line)); __rw_assert(c, RA_RLOCKED, file, line); /* * Attempt to switch from one reader to a writer. If there * are any write waiters, then we will have to lock the * turnstile first to prevent races with another writer * calling turnstile_wait() before we have claimed this * turnstile. So, do the simple case of no waiters first. */ tid = (uintptr_t)curthread; success = 0; for (;;) { v = rw->rw_lock; if (RW_READERS(v) > 1) break; if (!(v & RW_LOCK_WAITERS)) { success = atomic_cmpset_acq_ptr(&rw->rw_lock, v, tid); if (!success) continue; break; } /* * Ok, we think we have waiters, so lock the turnstile. */ ts = turnstile_trywait(&rw->lock_object); v = rw->rw_lock; if (RW_READERS(v) > 1) { turnstile_cancel(ts); break; } /* * Try to switch from one reader to a writer again. This time * we honor the current state of the waiters flags. * If we obtain the lock with the flags set, then claim * ownership of the turnstile. */ x = rw->rw_lock & RW_LOCK_WAITERS; success = atomic_cmpset_ptr(&rw->rw_lock, v, tid | x); if (success) { if (x) turnstile_claim(ts); else turnstile_cancel(ts); break; } turnstile_cancel(ts); } LOCK_LOG_TRY("WUPGRADE", &rw->lock_object, 0, success, file, line); if (success) { curthread->td_rw_rlocks--; WITNESS_UPGRADE(&rw->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file, line); LOCKSTAT_RECORD0(rw__upgrade, rw); } return (success); } /* * Downgrade a write lock into a single read lock. */ void __rw_downgrade(volatile uintptr_t *c, const char *file, int line) { struct rwlock *rw; struct turnstile *ts; uintptr_t tid, v; int rwait, wwait; if (SCHEDULER_STOPPED()) return; rw = rwlock2rw(c); KASSERT(rw->rw_lock != RW_DESTROYED, ("rw_downgrade() of destroyed rwlock @ %s:%d", file, line)); __rw_assert(c, RA_WLOCKED | RA_NOTRECURSED, file, line); #ifndef INVARIANTS if (rw_recursed(rw)) panic("downgrade of a recursed lock"); #endif WITNESS_DOWNGRADE(&rw->lock_object, 0, file, line); /* * Convert from a writer to a single reader. First we handle * the easy case with no waiters. If there are any waiters, we * lock the turnstile and "disown" the lock. */ tid = (uintptr_t)curthread; if (atomic_cmpset_rel_ptr(&rw->rw_lock, tid, RW_READERS_LOCK(1))) goto out; /* * Ok, we think we have waiters, so lock the turnstile so we can * read the waiter flags without any races. */ turnstile_chain_lock(&rw->lock_object); v = rw->rw_lock & RW_LOCK_WAITERS; rwait = v & RW_LOCK_READ_WAITERS; wwait = v & RW_LOCK_WRITE_WAITERS; MPASS(rwait | wwait); /* * Downgrade from a write lock while preserving waiters flag * and give up ownership of the turnstile. */ ts = turnstile_lookup(&rw->lock_object); MPASS(ts != NULL); if (!wwait) v &= ~RW_LOCK_READ_WAITERS; atomic_store_rel_ptr(&rw->rw_lock, RW_READERS_LOCK(1) | v); /* * Wake other readers if there are no writers pending. Otherwise they * won't be able to acquire the lock anyway. */ if (rwait && !wwait) { turnstile_broadcast(ts, TS_SHARED_QUEUE); turnstile_unpend(ts, TS_EXCLUSIVE_LOCK); } else turnstile_disown(ts); turnstile_chain_unlock(&rw->lock_object); out: curthread->td_rw_rlocks++; LOCK_LOG_LOCK("WDOWNGRADE", &rw->lock_object, 0, 0, file, line); LOCKSTAT_RECORD0(rw__downgrade, rw); } #ifdef INVARIANT_SUPPORT #ifndef INVARIANTS #undef __rw_assert #endif /* * In the non-WITNESS case, rw_assert() can only detect that at least * *some* thread owns an rlock, but it cannot guarantee that *this* * thread owns an rlock. */ void __rw_assert(const volatile uintptr_t *c, int what, const char *file, int line) { const struct rwlock *rw; if (panicstr != NULL) return; rw = rwlock2rw(c); switch (what) { case RA_LOCKED: case RA_LOCKED | RA_RECURSED: case RA_LOCKED | RA_NOTRECURSED: case RA_RLOCKED: case RA_RLOCKED | RA_RECURSED: case RA_RLOCKED | RA_NOTRECURSED: #ifdef WITNESS witness_assert(&rw->lock_object, what, file, line); #else /* * If some other thread has a write lock or we have one * and are asserting a read lock, fail. Also, if no one * has a lock at all, fail. */ if (rw->rw_lock == RW_UNLOCKED || (!(rw->rw_lock & RW_LOCK_READ) && (what & RA_RLOCKED || rw_wowner(rw) != curthread))) panic("Lock %s not %slocked @ %s:%d\n", rw->lock_object.lo_name, (what & RA_RLOCKED) ? "read " : "", file, line); if (!(rw->rw_lock & RW_LOCK_READ) && !(what & RA_RLOCKED)) { if (rw_recursed(rw)) { if (what & RA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", rw->lock_object.lo_name, file, line); } else if (what & RA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", rw->lock_object.lo_name, file, line); } #endif break; case RA_WLOCKED: case RA_WLOCKED | RA_RECURSED: case RA_WLOCKED | RA_NOTRECURSED: if (rw_wowner(rw) != curthread) panic("Lock %s not exclusively locked @ %s:%d\n", rw->lock_object.lo_name, file, line); if (rw_recursed(rw)) { if (what & RA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", rw->lock_object.lo_name, file, line); } else if (what & RA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", rw->lock_object.lo_name, file, line); break; case RA_UNLOCKED: #ifdef WITNESS witness_assert(&rw->lock_object, what, file, line); #else /* * If we hold a write lock fail. We can't reliably check * to see if we hold a read lock or not. */ if (rw_wowner(rw) == curthread) panic("Lock %s exclusively locked @ %s:%d\n", rw->lock_object.lo_name, file, line); #endif break; default: panic("Unknown rw lock assertion: %d @ %s:%d", what, file, line); } } #endif /* INVARIANT_SUPPORT */ #ifdef DDB void db_show_rwlock(const struct lock_object *lock) { const struct rwlock *rw; struct thread *td; rw = (const struct rwlock *)lock; db_printf(" state: "); if (rw->rw_lock == RW_UNLOCKED) db_printf("UNLOCKED\n"); else if (rw->rw_lock == RW_DESTROYED) { db_printf("DESTROYED\n"); return; } else if (rw->rw_lock & RW_LOCK_READ) db_printf("RLOCK: %ju locks\n", (uintmax_t)(RW_READERS(rw->rw_lock))); else { td = rw_wowner(rw); db_printf("WLOCK: %p (tid %d, pid %d, \"%s\")\n", td, td->td_tid, td->td_proc->p_pid, td->td_name); if (rw_recursed(rw)) db_printf(" recursed: %u\n", rw->rw_recurse); } db_printf(" waiters: "); switch (rw->rw_lock & (RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS)) { case RW_LOCK_READ_WAITERS: db_printf("readers\n"); break; case RW_LOCK_WRITE_WAITERS: db_printf("writers\n"); break; case RW_LOCK_READ_WAITERS | RW_LOCK_WRITE_WAITERS: db_printf("readers and writers\n"); break; default: db_printf("none\n"); break; } } #endif Index: stable/11/sys/kern/kern_sx.c =================================================================== --- stable/11/sys/kern/kern_sx.c (revision 315385) +++ stable/11/sys/kern/kern_sx.c (revision 315386) @@ -1,1317 +1,1313 @@ /*- * Copyright (c) 2007 Attilio Rao * Copyright (c) 2001 Jason Evans * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice(s), this list of conditions and the following disclaimer as * the first lines of this file unmodified other than the possible * addition of one or more copyright notices. * 2. Redistributions in binary form must reproduce the above copyright * notice(s), this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. */ /* * Shared/exclusive locks. This implementation attempts to ensure * deterministic lock granting behavior, so that slocks and xlocks are * interleaved. * * Priority propagation will not generally raise the priority of lock holders, * so should not be relied upon in combination with sx locks. */ #include "opt_ddb.h" #include "opt_hwpmc_hooks.h" #include "opt_no_adaptive_sx.h" #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(SMP) && !defined(NO_ADAPTIVE_SX) #include #endif #ifdef DDB #include #endif #if defined(SMP) && !defined(NO_ADAPTIVE_SX) #define ADAPTIVE_SX #endif CTASSERT((SX_NOADAPTIVE & LO_CLASSFLAGS) == SX_NOADAPTIVE); #ifdef HWPMC_HOOKS #include PMC_SOFT_DECLARE( , , lock, failed); #endif /* Handy macros for sleep queues. */ #define SQ_EXCLUSIVE_QUEUE 0 #define SQ_SHARED_QUEUE 1 /* * Variations on DROP_GIANT()/PICKUP_GIANT() for use in this file. We * drop Giant anytime we have to sleep or if we adaptively spin. */ #define GIANT_DECLARE \ int _giantcnt = 0; \ WITNESS_SAVE_DECL(Giant) \ #define GIANT_SAVE() do { \ if (mtx_owned(&Giant)) { \ WITNESS_SAVE(&Giant.lock_object, Giant); \ while (mtx_owned(&Giant)) { \ _giantcnt++; \ mtx_unlock(&Giant); \ } \ } \ } while (0) #define GIANT_RESTORE() do { \ if (_giantcnt > 0) { \ mtx_assert(&Giant, MA_NOTOWNED); \ while (_giantcnt--) \ mtx_lock(&Giant); \ WITNESS_RESTORE(&Giant.lock_object, Giant); \ } \ } while (0) /* * Returns true if an exclusive lock is recursed. It assumes * curthread currently has an exclusive lock. */ #define sx_recursed(sx) ((sx)->sx_recurse != 0) static void assert_sx(const struct lock_object *lock, int what); #ifdef DDB static void db_show_sx(const struct lock_object *lock); #endif static void lock_sx(struct lock_object *lock, uintptr_t how); #ifdef KDTRACE_HOOKS static int owner_sx(const struct lock_object *lock, struct thread **owner); #endif static uintptr_t unlock_sx(struct lock_object *lock); struct lock_class lock_class_sx = { .lc_name = "sx", .lc_flags = LC_SLEEPLOCK | LC_SLEEPABLE | LC_RECURSABLE | LC_UPGRADABLE, .lc_assert = assert_sx, #ifdef DDB .lc_ddb_show = db_show_sx, #endif .lc_lock = lock_sx, .lc_unlock = unlock_sx, #ifdef KDTRACE_HOOKS .lc_owner = owner_sx, #endif }; #ifndef INVARIANTS #define _sx_assert(sx, what, file, line) #endif #ifdef ADAPTIVE_SX static u_int asx_retries = 10; static u_int asx_loops = 10000; static SYSCTL_NODE(_debug, OID_AUTO, sx, CTLFLAG_RD, NULL, "sxlock debugging"); SYSCTL_UINT(_debug_sx, OID_AUTO, retries, CTLFLAG_RW, &asx_retries, 0, ""); SYSCTL_UINT(_debug_sx, OID_AUTO, loops, CTLFLAG_RW, &asx_loops, 0, ""); static struct lock_delay_config __read_mostly sx_delay; SYSCTL_INT(_debug_sx, OID_AUTO, delay_base, CTLFLAG_RW, &sx_delay.base, 0, ""); SYSCTL_INT(_debug_sx, OID_AUTO, delay_max, CTLFLAG_RW, &sx_delay.max, 0, ""); LOCK_DELAY_SYSINIT_DEFAULT(sx_delay); #endif void assert_sx(const struct lock_object *lock, int what) { sx_assert((const struct sx *)lock, what); } void lock_sx(struct lock_object *lock, uintptr_t how) { struct sx *sx; sx = (struct sx *)lock; if (how) sx_slock(sx); else sx_xlock(sx); } uintptr_t unlock_sx(struct lock_object *lock) { struct sx *sx; sx = (struct sx *)lock; sx_assert(sx, SA_LOCKED | SA_NOTRECURSED); if (sx_xlocked(sx)) { sx_xunlock(sx); return (0); } else { sx_sunlock(sx); return (1); } } #ifdef KDTRACE_HOOKS int owner_sx(const struct lock_object *lock, struct thread **owner) { const struct sx *sx = (const struct sx *)lock; uintptr_t x = sx->sx_lock; *owner = (struct thread *)SX_OWNER(x); return ((x & SX_LOCK_SHARED) != 0 ? (SX_SHARERS(x) != 0) : (*owner != NULL)); } #endif void sx_sysinit(void *arg) { struct sx_args *sargs = arg; sx_init_flags(sargs->sa_sx, sargs->sa_desc, sargs->sa_flags); } void sx_init_flags(struct sx *sx, const char *description, int opts) { int flags; MPASS((opts & ~(SX_QUIET | SX_RECURSE | SX_NOWITNESS | SX_DUPOK | SX_NOPROFILE | SX_NOADAPTIVE | SX_NEW)) == 0); ASSERT_ATOMIC_LOAD_PTR(sx->sx_lock, ("%s: sx_lock not aligned for %s: %p", __func__, description, &sx->sx_lock)); flags = LO_SLEEPABLE | LO_UPGRADABLE; if (opts & SX_DUPOK) flags |= LO_DUPOK; if (opts & SX_NOPROFILE) flags |= LO_NOPROFILE; if (!(opts & SX_NOWITNESS)) flags |= LO_WITNESS; if (opts & SX_RECURSE) flags |= LO_RECURSABLE; if (opts & SX_QUIET) flags |= LO_QUIET; if (opts & SX_NEW) flags |= LO_NEW; flags |= opts & SX_NOADAPTIVE; lock_init(&sx->lock_object, &lock_class_sx, description, NULL, flags); sx->sx_lock = SX_LOCK_UNLOCKED; sx->sx_recurse = 0; } void sx_destroy(struct sx *sx) { KASSERT(sx->sx_lock == SX_LOCK_UNLOCKED, ("sx lock still held")); KASSERT(sx->sx_recurse == 0, ("sx lock still recursed")); sx->sx_lock = SX_LOCK_DESTROYED; lock_destroy(&sx->lock_object); } int sx_try_slock_(struct sx *sx, const char *file, int line) { uintptr_t x; if (SCHEDULER_STOPPED()) return (1); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("sx_try_slock() by idle thread %p on sx %s @ %s:%d", curthread, sx->lock_object.lo_name, file, line)); for (;;) { x = sx->sx_lock; KASSERT(x != SX_LOCK_DESTROYED, ("sx_try_slock() of destroyed sx @ %s:%d", file, line)); if (!(x & SX_LOCK_SHARED)) break; if (atomic_cmpset_acq_ptr(&sx->sx_lock, x, x + SX_ONE_SHARER)) { LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 1, file, line); WITNESS_LOCK(&sx->lock_object, LOP_TRYLOCK, file, line); LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx, 0, 0, file, line, LOCKSTAT_READER); TD_LOCKS_INC(curthread); return (1); } } LOCK_LOG_TRY("SLOCK", &sx->lock_object, 0, 0, file, line); return (0); } int _sx_xlock(struct sx *sx, int opts, const char *file, int line) { uintptr_t tid, x; int error = 0; - if (SCHEDULER_STOPPED()) - return (0); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("sx_xlock() by idle thread %p on sx %s @ %s:%d", curthread, sx->lock_object.lo_name, file, line)); KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_xlock() of destroyed sx @ %s:%d", file, line)); WITNESS_CHECKORDER(&sx->lock_object, LOP_NEWORDER | LOP_EXCLUSIVE, file, line, NULL); tid = (uintptr_t)curthread; x = SX_LOCK_UNLOCKED; if (!atomic_fcmpset_acq_ptr(&sx->sx_lock, &x, tid)) error = _sx_xlock_hard(sx, x, tid, opts, file, line); else LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx, 0, 0, file, line, LOCKSTAT_WRITER); if (!error) { LOCK_LOG_LOCK("XLOCK", &sx->lock_object, 0, sx->sx_recurse, file, line); WITNESS_LOCK(&sx->lock_object, LOP_EXCLUSIVE, file, line); TD_LOCKS_INC(curthread); } return (error); } int sx_try_xlock_(struct sx *sx, const char *file, int line) { int rval; if (SCHEDULER_STOPPED()) return (1); KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("sx_try_xlock() by idle thread %p on sx %s @ %s:%d", curthread, sx->lock_object.lo_name, file, line)); KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_try_xlock() of destroyed sx @ %s:%d", file, line)); if (sx_xlocked(sx) && (sx->lock_object.lo_flags & LO_RECURSABLE) != 0) { sx->sx_recurse++; atomic_set_ptr(&sx->sx_lock, SX_LOCK_RECURSED); rval = 1; } else rval = atomic_cmpset_acq_ptr(&sx->sx_lock, SX_LOCK_UNLOCKED, (uintptr_t)curthread); LOCK_LOG_TRY("XLOCK", &sx->lock_object, 0, rval, file, line); if (rval) { WITNESS_LOCK(&sx->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file, line); if (!sx_recursed(sx)) LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx, 0, 0, file, line, LOCKSTAT_WRITER); TD_LOCKS_INC(curthread); } return (rval); } void _sx_xunlock(struct sx *sx, const char *file, int line) { - if (SCHEDULER_STOPPED()) - return; KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_xunlock() of destroyed sx @ %s:%d", file, line)); _sx_assert(sx, SA_XLOCKED, file, line); WITNESS_UNLOCK(&sx->lock_object, LOP_EXCLUSIVE, file, line); LOCK_LOG_LOCK("XUNLOCK", &sx->lock_object, 0, sx->sx_recurse, file, line); _sx_xunlock_hard(sx, (uintptr_t)curthread, file, line); TD_LOCKS_DEC(curthread); } /* * Try to do a non-blocking upgrade from a shared lock to an exclusive lock. * This will only succeed if this thread holds a single shared lock. * Return 1 if if the upgrade succeed, 0 otherwise. */ int sx_try_upgrade_(struct sx *sx, const char *file, int line) { uintptr_t x; int success; if (SCHEDULER_STOPPED()) return (1); KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_try_upgrade() of destroyed sx @ %s:%d", file, line)); _sx_assert(sx, SA_SLOCKED, file, line); /* * Try to switch from one shared lock to an exclusive lock. We need * to maintain the SX_LOCK_EXCLUSIVE_WAITERS flag if set so that * we will wake up the exclusive waiters when we drop the lock. */ x = sx->sx_lock & SX_LOCK_EXCLUSIVE_WAITERS; success = atomic_cmpset_acq_ptr(&sx->sx_lock, SX_SHARERS_LOCK(1) | x, (uintptr_t)curthread | x); LOCK_LOG_TRY("XUPGRADE", &sx->lock_object, 0, success, file, line); if (success) { WITNESS_UPGRADE(&sx->lock_object, LOP_EXCLUSIVE | LOP_TRYLOCK, file, line); LOCKSTAT_RECORD0(sx__upgrade, sx); } return (success); } /* * Downgrade an unrecursed exclusive lock into a single shared lock. */ void sx_downgrade_(struct sx *sx, const char *file, int line) { uintptr_t x; int wakeup_swapper; if (SCHEDULER_STOPPED()) return; KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_downgrade() of destroyed sx @ %s:%d", file, line)); _sx_assert(sx, SA_XLOCKED | SA_NOTRECURSED, file, line); #ifndef INVARIANTS if (sx_recursed(sx)) panic("downgrade of a recursed lock"); #endif WITNESS_DOWNGRADE(&sx->lock_object, 0, file, line); /* * Try to switch from an exclusive lock with no shared waiters * to one sharer with no shared waiters. If there are * exclusive waiters, we don't need to lock the sleep queue so * long as we preserve the flag. We do one quick try and if * that fails we grab the sleepq lock to keep the flags from * changing and do it the slow way. * * We have to lock the sleep queue if there are shared waiters * so we can wake them up. */ x = sx->sx_lock; if (!(x & SX_LOCK_SHARED_WAITERS) && atomic_cmpset_rel_ptr(&sx->sx_lock, x, SX_SHARERS_LOCK(1) | (x & SX_LOCK_EXCLUSIVE_WAITERS))) { LOCK_LOG_LOCK("XDOWNGRADE", &sx->lock_object, 0, 0, file, line); return; } /* * Lock the sleep queue so we can read the waiters bits * without any races and wakeup any shared waiters. */ sleepq_lock(&sx->lock_object); /* * Preserve SX_LOCK_EXCLUSIVE_WAITERS while downgraded to a single * shared lock. If there are any shared waiters, wake them up. */ wakeup_swapper = 0; x = sx->sx_lock; atomic_store_rel_ptr(&sx->sx_lock, SX_SHARERS_LOCK(1) | (x & SX_LOCK_EXCLUSIVE_WAITERS)); if (x & SX_LOCK_SHARED_WAITERS) wakeup_swapper = sleepq_broadcast(&sx->lock_object, SLEEPQ_SX, 0, SQ_SHARED_QUEUE); sleepq_release(&sx->lock_object); LOCK_LOG_LOCK("XDOWNGRADE", &sx->lock_object, 0, 0, file, line); LOCKSTAT_RECORD0(sx__downgrade, sx); if (wakeup_swapper) kick_proc0(); } /* * This function represents the so-called 'hard case' for sx_xlock * operation. All 'easy case' failures are redirected to this. Note * that ideally this would be a static function, but it needs to be * accessible from at least sx.h. */ int _sx_xlock_hard(struct sx *sx, uintptr_t x, uintptr_t tid, int opts, const char *file, int line) { GIANT_DECLARE; #ifdef ADAPTIVE_SX volatile struct thread *owner; u_int i, spintries = 0; #endif #ifdef LOCK_PROFILING uint64_t waittime = 0; int contested = 0; #endif int error = 0; #if defined(ADAPTIVE_SX) || defined(KDTRACE_HOOKS) struct lock_delay_arg lda; #endif #ifdef KDTRACE_HOOKS uintptr_t state; u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif if (SCHEDULER_STOPPED()) return (0); #if defined(ADAPTIVE_SX) lock_delay_arg_init(&lda, &sx_delay); #elif defined(KDTRACE_HOOKS) lock_delay_arg_init(&lda, NULL); #endif if (__predict_false(x == SX_LOCK_UNLOCKED)) x = SX_READ_VALUE(sx); /* If we already hold an exclusive lock, then recurse. */ if (__predict_false(lv_sx_owner(x) == (struct thread *)tid)) { KASSERT((sx->lock_object.lo_flags & LO_RECURSABLE) != 0, ("_sx_xlock_hard: recursed on non-recursive sx %s @ %s:%d\n", sx->lock_object.lo_name, file, line)); sx->sx_recurse++; atomic_set_ptr(&sx->sx_lock, SX_LOCK_RECURSED); if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p recursing", __func__, sx); return (0); } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR5(KTR_LOCK, "%s: %s contested (lock=%p) at %s:%d", __func__, sx->lock_object.lo_name, (void *)sx->sx_lock, file, line); #ifdef KDTRACE_HOOKS all_time -= lockstat_nsecs(&sx->lock_object); state = x; #endif for (;;) { if (x == SX_LOCK_UNLOCKED) { if (atomic_fcmpset_acq_ptr(&sx->sx_lock, &x, tid)) break; continue; } #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&sx->lock_object, &contested, &waittime); #ifdef ADAPTIVE_SX /* * If the lock is write locked and the owner is * running on another CPU, spin until the owner stops * running or the state of the lock changes. */ if ((sx->lock_object.lo_flags & SX_NOADAPTIVE) == 0) { if ((x & SX_LOCK_SHARED) == 0) { owner = lv_sx_owner(x); if (TD_IS_RUNNING(owner)) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR3(KTR_LOCK, "%s: spinning on %p held by %p", __func__, sx, owner); KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", sx->lock_object.lo_name); GIANT_SAVE(); do { lock_delay(&lda); x = SX_READ_VALUE(sx); owner = lv_sx_owner(x); } while (owner != NULL && TD_IS_RUNNING(owner)); KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); continue; } } else if (SX_SHARERS(x) && spintries < asx_retries) { KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", sx->lock_object.lo_name); GIANT_SAVE(); spintries++; for (i = 0; i < asx_loops; i++) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR4(KTR_LOCK, "%s: shared spinning on %p with %u and %u", __func__, sx, spintries, i); x = sx->sx_lock; if ((x & SX_LOCK_SHARED) == 0 || SX_SHARERS(x) == 0) break; cpu_spinwait(); #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif } KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); x = SX_READ_VALUE(sx); if (i != asx_loops) continue; } } #endif sleepq_lock(&sx->lock_object); x = SX_READ_VALUE(sx); /* * If the lock was released while spinning on the * sleep queue chain lock, try again. */ if (x == SX_LOCK_UNLOCKED) { sleepq_release(&sx->lock_object); continue; } #ifdef ADAPTIVE_SX /* * The current lock owner might have started executing * on another CPU (or the lock could have changed * owners) while we were waiting on the sleep queue * chain lock. If so, drop the sleep queue lock and try * again. */ if (!(x & SX_LOCK_SHARED) && (sx->lock_object.lo_flags & SX_NOADAPTIVE) == 0) { owner = (struct thread *)SX_OWNER(x); if (TD_IS_RUNNING(owner)) { sleepq_release(&sx->lock_object); continue; } } #endif /* * If an exclusive lock was released with both shared * and exclusive waiters and a shared waiter hasn't * woken up and acquired the lock yet, sx_lock will be * set to SX_LOCK_UNLOCKED | SX_LOCK_EXCLUSIVE_WAITERS. * If we see that value, try to acquire it once. Note * that we have to preserve SX_LOCK_EXCLUSIVE_WAITERS * as there are other exclusive waiters still. If we * fail, restart the loop. */ if (x == (SX_LOCK_UNLOCKED | SX_LOCK_EXCLUSIVE_WAITERS)) { if (atomic_cmpset_acq_ptr(&sx->sx_lock, SX_LOCK_UNLOCKED | SX_LOCK_EXCLUSIVE_WAITERS, tid | SX_LOCK_EXCLUSIVE_WAITERS)) { sleepq_release(&sx->lock_object); CTR2(KTR_LOCK, "%s: %p claimed by new writer", __func__, sx); break; } sleepq_release(&sx->lock_object); x = SX_READ_VALUE(sx); continue; } /* * Try to set the SX_LOCK_EXCLUSIVE_WAITERS. If we fail, * than loop back and retry. */ if (!(x & SX_LOCK_EXCLUSIVE_WAITERS)) { if (!atomic_cmpset_ptr(&sx->sx_lock, x, x | SX_LOCK_EXCLUSIVE_WAITERS)) { sleepq_release(&sx->lock_object); x = SX_READ_VALUE(sx); continue; } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p set excl waiters flag", __func__, sx); } /* * Since we have been unable to acquire the exclusive * lock and the exclusive waiters flag is set, we have * to sleep. */ if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p blocking on sleep queue", __func__, sx); #ifdef KDTRACE_HOOKS sleep_time -= lockstat_nsecs(&sx->lock_object); #endif GIANT_SAVE(); sleepq_add(&sx->lock_object, NULL, sx->lock_object.lo_name, SLEEPQ_SX | ((opts & SX_INTERRUPTIBLE) ? SLEEPQ_INTERRUPTIBLE : 0), SQ_EXCLUSIVE_QUEUE); if (!(opts & SX_INTERRUPTIBLE)) sleepq_wait(&sx->lock_object, 0); else error = sleepq_wait_sig(&sx->lock_object, 0); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&sx->lock_object); sleep_cnt++; #endif if (error) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: interruptible sleep by %p suspended by signal", __func__, sx); break; } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p resuming from sleep queue", __func__, sx); x = SX_READ_VALUE(sx); } #ifdef KDTRACE_HOOKS all_time += lockstat_nsecs(&sx->lock_object); if (sleep_time) LOCKSTAT_RECORD4(sx__block, sx, sleep_time, LOCKSTAT_WRITER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(sx__spin, sx, all_time - sleep_time, LOCKSTAT_WRITER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); #endif if (!error) LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx, contested, waittime, file, line, LOCKSTAT_WRITER); GIANT_RESTORE(); return (error); } /* * This function represents the so-called 'hard case' for sx_xunlock * operation. All 'easy case' failures are redirected to this. Note * that ideally this would be a static function, but it needs to be * accessible from at least sx.h. */ void _sx_xunlock_hard(struct sx *sx, uintptr_t tid, const char *file, int line) { uintptr_t x; int queue, wakeup_swapper; if (SCHEDULER_STOPPED()) return; MPASS(!(sx->sx_lock & SX_LOCK_SHARED)); x = SX_READ_VALUE(sx); if (x & SX_LOCK_RECURSED) { /* The lock is recursed, unrecurse one level. */ if ((--sx->sx_recurse) == 0) atomic_clear_ptr(&sx->sx_lock, SX_LOCK_RECURSED); if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p unrecursing", __func__, sx); return; } LOCKSTAT_PROFILE_RELEASE_RWLOCK(sx__release, sx, LOCKSTAT_WRITER); if (x == tid && atomic_cmpset_rel_ptr(&sx->sx_lock, tid, SX_LOCK_UNLOCKED)) return; MPASS(sx->sx_lock & (SX_LOCK_SHARED_WAITERS | SX_LOCK_EXCLUSIVE_WAITERS)); if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p contested", __func__, sx); sleepq_lock(&sx->lock_object); x = SX_LOCK_UNLOCKED; /* * The wake up algorithm here is quite simple and probably not * ideal. It gives precedence to shared waiters if they are * present. For this condition, we have to preserve the * state of the exclusive waiters flag. * If interruptible sleeps left the shared queue empty avoid a * starvation for the threads sleeping on the exclusive queue by giving * them precedence and cleaning up the shared waiters bit anyway. */ if ((sx->sx_lock & SX_LOCK_SHARED_WAITERS) != 0 && sleepq_sleepcnt(&sx->lock_object, SQ_SHARED_QUEUE) != 0) { queue = SQ_SHARED_QUEUE; x |= (sx->sx_lock & SX_LOCK_EXCLUSIVE_WAITERS); } else queue = SQ_EXCLUSIVE_QUEUE; /* Wake up all the waiters for the specific queue. */ if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR3(KTR_LOCK, "%s: %p waking up all threads on %s queue", __func__, sx, queue == SQ_SHARED_QUEUE ? "shared" : "exclusive"); atomic_store_rel_ptr(&sx->sx_lock, x); wakeup_swapper = sleepq_broadcast(&sx->lock_object, SLEEPQ_SX, 0, queue); sleepq_release(&sx->lock_object); if (wakeup_swapper) kick_proc0(); } static bool __always_inline __sx_slock_try(struct sx *sx, uintptr_t *xp, const char *file, int line) { /* * If no other thread has an exclusive lock then try to bump up * the count of sharers. Since we have to preserve the state * of SX_LOCK_EXCLUSIVE_WAITERS, if we fail to acquire the * shared lock loop back and retry. */ while (*xp & SX_LOCK_SHARED) { MPASS(!(*xp & SX_LOCK_SHARED_WAITERS)); if (atomic_fcmpset_acq_ptr(&sx->sx_lock, xp, *xp + SX_ONE_SHARER)) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR4(KTR_LOCK, "%s: %p succeed %p -> %p", __func__, sx, (void *)*xp, (void *)(*xp + SX_ONE_SHARER)); return (true); } } return (false); } static int __noinline _sx_slock_hard(struct sx *sx, int opts, const char *file, int line, uintptr_t x) { GIANT_DECLARE; #ifdef ADAPTIVE_SX volatile struct thread *owner; #endif #ifdef LOCK_PROFILING uint64_t waittime = 0; int contested = 0; #endif int error = 0; #if defined(ADAPTIVE_SX) || defined(KDTRACE_HOOKS) struct lock_delay_arg lda; #endif #ifdef KDTRACE_HOOKS uintptr_t state; u_int sleep_cnt = 0; int64_t sleep_time = 0; int64_t all_time = 0; #endif if (SCHEDULER_STOPPED()) return (0); #if defined(ADAPTIVE_SX) lock_delay_arg_init(&lda, &sx_delay); #elif defined(KDTRACE_HOOKS) lock_delay_arg_init(&lda, NULL); #endif #ifdef KDTRACE_HOOKS all_time -= lockstat_nsecs(&sx->lock_object); state = x; #endif /* * As with rwlocks, we don't make any attempt to try to block * shared locks once there is an exclusive waiter. */ for (;;) { if (__sx_slock_try(sx, &x, file, line)) break; #ifdef KDTRACE_HOOKS lda.spin_cnt++; #endif #ifdef HWPMC_HOOKS PMC_SOFT_CALL( , , lock, failed); #endif lock_profile_obtain_lock_failed(&sx->lock_object, &contested, &waittime); #ifdef ADAPTIVE_SX /* * If the owner is running on another CPU, spin until * the owner stops running or the state of the lock * changes. */ if ((sx->lock_object.lo_flags & SX_NOADAPTIVE) == 0) { owner = lv_sx_owner(x); if (TD_IS_RUNNING(owner)) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR3(KTR_LOCK, "%s: spinning on %p held by %p", __func__, sx, owner); KTR_STATE1(KTR_SCHED, "thread", sched_tdname(curthread), "spinning", "lockname:\"%s\"", sx->lock_object.lo_name); GIANT_SAVE(); do { lock_delay(&lda); x = SX_READ_VALUE(sx); owner = lv_sx_owner(x); } while (owner != NULL && TD_IS_RUNNING(owner)); KTR_STATE0(KTR_SCHED, "thread", sched_tdname(curthread), "running"); continue; } } #endif /* * Some other thread already has an exclusive lock, so * start the process of blocking. */ sleepq_lock(&sx->lock_object); x = SX_READ_VALUE(sx); /* * The lock could have been released while we spun. * In this case loop back and retry. */ if (x & SX_LOCK_SHARED) { sleepq_release(&sx->lock_object); continue; } #ifdef ADAPTIVE_SX /* * If the owner is running on another CPU, spin until * the owner stops running or the state of the lock * changes. */ if (!(x & SX_LOCK_SHARED) && (sx->lock_object.lo_flags & SX_NOADAPTIVE) == 0) { owner = (struct thread *)SX_OWNER(x); if (TD_IS_RUNNING(owner)) { sleepq_release(&sx->lock_object); x = SX_READ_VALUE(sx); continue; } } #endif /* * Try to set the SX_LOCK_SHARED_WAITERS flag. If we * fail to set it drop the sleep queue lock and loop * back. */ if (!(x & SX_LOCK_SHARED_WAITERS)) { if (!atomic_cmpset_ptr(&sx->sx_lock, x, x | SX_LOCK_SHARED_WAITERS)) { sleepq_release(&sx->lock_object); x = SX_READ_VALUE(sx); continue; } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p set shared waiters flag", __func__, sx); } /* * Since we have been unable to acquire the shared lock, * we have to sleep. */ if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p blocking on sleep queue", __func__, sx); #ifdef KDTRACE_HOOKS sleep_time -= lockstat_nsecs(&sx->lock_object); #endif GIANT_SAVE(); sleepq_add(&sx->lock_object, NULL, sx->lock_object.lo_name, SLEEPQ_SX | ((opts & SX_INTERRUPTIBLE) ? SLEEPQ_INTERRUPTIBLE : 0), SQ_SHARED_QUEUE); if (!(opts & SX_INTERRUPTIBLE)) sleepq_wait(&sx->lock_object, 0); else error = sleepq_wait_sig(&sx->lock_object, 0); #ifdef KDTRACE_HOOKS sleep_time += lockstat_nsecs(&sx->lock_object); sleep_cnt++; #endif if (error) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: interruptible sleep by %p suspended by signal", __func__, sx); break; } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p resuming from sleep queue", __func__, sx); x = SX_READ_VALUE(sx); } #ifdef KDTRACE_HOOKS all_time += lockstat_nsecs(&sx->lock_object); if (sleep_time) LOCKSTAT_RECORD4(sx__block, sx, sleep_time, LOCKSTAT_READER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); if (lda.spin_cnt > sleep_cnt) LOCKSTAT_RECORD4(sx__spin, sx, all_time - sleep_time, LOCKSTAT_READER, (state & SX_LOCK_SHARED) == 0, (state & SX_LOCK_SHARED) == 0 ? 0 : SX_SHARERS(state)); #endif if (error == 0) { LOCKSTAT_PROFILE_OBTAIN_RWLOCK_SUCCESS(sx__acquire, sx, contested, waittime, file, line, LOCKSTAT_READER); } GIANT_RESTORE(); return (error); } int _sx_slock(struct sx *sx, int opts, const char *file, int line) { uintptr_t x; int error; KASSERT(kdb_active != 0 || !TD_IS_IDLETHREAD(curthread), ("sx_slock() by idle thread %p on sx %s @ %s:%d", curthread, sx->lock_object.lo_name, file, line)); KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_slock() of destroyed sx @ %s:%d", file, line)); WITNESS_CHECKORDER(&sx->lock_object, LOP_NEWORDER, file, line, NULL); error = 0; x = SX_READ_VALUE(sx); if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(sx__acquire) || !__sx_slock_try(sx, &x, file, line))) error = _sx_slock_hard(sx, opts, file, line, x); if (error == 0) { LOCK_LOG_LOCK("SLOCK", &sx->lock_object, 0, 0, file, line); WITNESS_LOCK(&sx->lock_object, 0, file, line); TD_LOCKS_INC(curthread); } return (error); } static bool __always_inline _sx_sunlock_try(struct sx *sx, uintptr_t *xp) { for (;;) { /* * We should never have sharers while at least one thread * holds a shared lock. */ KASSERT(!(*xp & SX_LOCK_SHARED_WAITERS), ("%s: waiting sharers", __func__)); /* * See if there is more than one shared lock held. If * so, just drop one and return. */ if (SX_SHARERS(*xp) > 1) { if (atomic_fcmpset_rel_ptr(&sx->sx_lock, xp, *xp - SX_ONE_SHARER)) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR4(KTR_LOCK, "%s: %p succeeded %p -> %p", __func__, sx, (void *)*xp, (void *)(*xp - SX_ONE_SHARER)); return (true); } continue; } /* * If there aren't any waiters for an exclusive lock, * then try to drop it quickly. */ if (!(*xp & SX_LOCK_EXCLUSIVE_WAITERS)) { MPASS(*xp == SX_SHARERS_LOCK(1)); *xp = SX_SHARERS_LOCK(1); if (atomic_fcmpset_rel_ptr(&sx->sx_lock, xp, SX_LOCK_UNLOCKED)) { if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p last succeeded", __func__, sx); return (true); } continue; } break; } return (false); } static void __noinline _sx_sunlock_hard(struct sx *sx, uintptr_t x, const char *file, int line) { int wakeup_swapper; if (SCHEDULER_STOPPED()) return; LOCKSTAT_PROFILE_RELEASE_RWLOCK(sx__release, sx, LOCKSTAT_READER); for (;;) { if (_sx_sunlock_try(sx, &x)) break; /* * At this point, there should just be one sharer with * exclusive waiters. */ MPASS(x == (SX_SHARERS_LOCK(1) | SX_LOCK_EXCLUSIVE_WAITERS)); sleepq_lock(&sx->lock_object); /* * Wake up semantic here is quite simple: * Just wake up all the exclusive waiters. * Note that the state of the lock could have changed, * so if it fails loop back and retry. */ if (!atomic_cmpset_rel_ptr(&sx->sx_lock, SX_SHARERS_LOCK(1) | SX_LOCK_EXCLUSIVE_WAITERS, SX_LOCK_UNLOCKED)) { sleepq_release(&sx->lock_object); x = SX_READ_VALUE(sx); continue; } if (LOCK_LOG_TEST(&sx->lock_object, 0)) CTR2(KTR_LOCK, "%s: %p waking up all thread on" "exclusive queue", __func__, sx); wakeup_swapper = sleepq_broadcast(&sx->lock_object, SLEEPQ_SX, 0, SQ_EXCLUSIVE_QUEUE); sleepq_release(&sx->lock_object); if (wakeup_swapper) kick_proc0(); break; } } void _sx_sunlock(struct sx *sx, const char *file, int line) { uintptr_t x; KASSERT(sx->sx_lock != SX_LOCK_DESTROYED, ("sx_sunlock() of destroyed sx @ %s:%d", file, line)); _sx_assert(sx, SA_SLOCKED, file, line); WITNESS_UNLOCK(&sx->lock_object, 0, file, line); LOCK_LOG_LOCK("SUNLOCK", &sx->lock_object, 0, 0, file, line); x = SX_READ_VALUE(sx); if (__predict_false(LOCKSTAT_OOL_PROFILE_ENABLED(sx__release) || !_sx_sunlock_try(sx, &x))) _sx_sunlock_hard(sx, x, file, line); TD_LOCKS_DEC(curthread); } #ifdef INVARIANT_SUPPORT #ifndef INVARIANTS #undef _sx_assert #endif /* * In the non-WITNESS case, sx_assert() can only detect that at least * *some* thread owns an slock, but it cannot guarantee that *this* * thread owns an slock. */ void _sx_assert(const struct sx *sx, int what, const char *file, int line) { #ifndef WITNESS int slocked = 0; #endif if (panicstr != NULL) return; switch (what) { case SA_SLOCKED: case SA_SLOCKED | SA_NOTRECURSED: case SA_SLOCKED | SA_RECURSED: #ifndef WITNESS slocked = 1; /* FALLTHROUGH */ #endif case SA_LOCKED: case SA_LOCKED | SA_NOTRECURSED: case SA_LOCKED | SA_RECURSED: #ifdef WITNESS witness_assert(&sx->lock_object, what, file, line); #else /* * If some other thread has an exclusive lock or we * have one and are asserting a shared lock, fail. * Also, if no one has a lock at all, fail. */ if (sx->sx_lock == SX_LOCK_UNLOCKED || (!(sx->sx_lock & SX_LOCK_SHARED) && (slocked || sx_xholder(sx) != curthread))) panic("Lock %s not %slocked @ %s:%d\n", sx->lock_object.lo_name, slocked ? "share " : "", file, line); if (!(sx->sx_lock & SX_LOCK_SHARED)) { if (sx_recursed(sx)) { if (what & SA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } else if (what & SA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } #endif break; case SA_XLOCKED: case SA_XLOCKED | SA_NOTRECURSED: case SA_XLOCKED | SA_RECURSED: if (sx_xholder(sx) != curthread) panic("Lock %s not exclusively locked @ %s:%d\n", sx->lock_object.lo_name, file, line); if (sx_recursed(sx)) { if (what & SA_NOTRECURSED) panic("Lock %s recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); } else if (what & SA_RECURSED) panic("Lock %s not recursed @ %s:%d\n", sx->lock_object.lo_name, file, line); break; case SA_UNLOCKED: #ifdef WITNESS witness_assert(&sx->lock_object, what, file, line); #else /* * If we hold an exclusve lock fail. We can't * reliably check to see if we hold a shared lock or * not. */ if (sx_xholder(sx) == curthread) panic("Lock %s exclusively locked @ %s:%d\n", sx->lock_object.lo_name, file, line); #endif break; default: panic("Unknown sx lock assertion: %d @ %s:%d", what, file, line); } } #endif /* INVARIANT_SUPPORT */ #ifdef DDB static void db_show_sx(const struct lock_object *lock) { struct thread *td; const struct sx *sx; sx = (const struct sx *)lock; db_printf(" state: "); if (sx->sx_lock == SX_LOCK_UNLOCKED) db_printf("UNLOCKED\n"); else if (sx->sx_lock == SX_LOCK_DESTROYED) { db_printf("DESTROYED\n"); return; } else if (sx->sx_lock & SX_LOCK_SHARED) db_printf("SLOCK: %ju\n", (uintmax_t)SX_SHARERS(sx->sx_lock)); else { td = sx_xholder(sx); db_printf("XLOCK: %p (tid %d, pid %d, \"%s\")\n", td, td->td_tid, td->td_proc->p_pid, td->td_name); if (sx_recursed(sx)) db_printf(" recursed: %d\n", sx->sx_recurse); } db_printf(" waiters: "); switch(sx->sx_lock & (SX_LOCK_SHARED_WAITERS | SX_LOCK_EXCLUSIVE_WAITERS)) { case SX_LOCK_SHARED_WAITERS: db_printf("shared\n"); break; case SX_LOCK_EXCLUSIVE_WAITERS: db_printf("exclusive\n"); break; case SX_LOCK_SHARED_WAITERS | SX_LOCK_EXCLUSIVE_WAITERS: db_printf("exclusive and shared\n"); break; default: db_printf("none\n"); } } /* * Check to see if a thread that is blocked on a sleep queue is actually * blocked on an sx lock. If so, output some details and return true. * If the lock has an exclusive owner, return that in *ownerp. */ int sx_chain(struct thread *td, struct thread **ownerp) { struct sx *sx; /* * Check to see if this thread is blocked on an sx lock. * First, we check the lock class. If that is ok, then we * compare the lock name against the wait message. */ sx = td->td_wchan; if (LOCK_CLASS(&sx->lock_object) != &lock_class_sx || sx->lock_object.lo_name != td->td_wmesg) return (0); /* We think we have an sx lock, so output some details. */ db_printf("blocked on sx \"%s\" ", td->td_wmesg); *ownerp = sx_xholder(sx); if (sx->sx_lock & SX_LOCK_SHARED) db_printf("SLOCK (count %ju)\n", (uintmax_t)SX_SHARERS(sx->sx_lock)); else db_printf("XLOCK\n"); return (1); } #endif Index: stable/11/sys/kern/kern_synch.c =================================================================== --- stable/11/sys/kern/kern_synch.c (revision 315385) +++ stable/11/sys/kern/kern_synch.c (revision 315386) @@ -1,589 +1,589 @@ /*- * Copyright (c) 1982, 1986, 1990, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)kern_synch.c 8.9 (Berkeley) 5/19/95 */ #include __FBSDID("$FreeBSD$"); #include "opt_ktrace.h" #include "opt_sched.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef KTRACE #include #include #endif #include #define KTDSTATE(td) \ (((td)->td_inhibitors & TDI_SLEEPING) != 0 ? "sleep" : \ ((td)->td_inhibitors & TDI_SUSPENDED) != 0 ? "suspended" : \ ((td)->td_inhibitors & TDI_SWAPPED) != 0 ? "swapped" : \ ((td)->td_inhibitors & TDI_LOCK) != 0 ? "blocked" : \ ((td)->td_inhibitors & TDI_IWAIT) != 0 ? "iwait" : "yielding") static void synch_setup(void *dummy); SYSINIT(synch_setup, SI_SUB_KICK_SCHEDULER, SI_ORDER_FIRST, synch_setup, NULL); int hogticks; static uint8_t pause_wchan[MAXCPU]; static struct callout loadav_callout; struct loadavg averunnable = { {0, 0, 0}, FSCALE }; /* load average, of runnable procs */ /* * Constants for averages over 1, 5, and 15 minutes * when sampling at 5 second intervals. */ static fixpt_t cexp[3] = { 0.9200444146293232 * FSCALE, /* exp(-1/12) */ 0.9834714538216174 * FSCALE, /* exp(-1/60) */ 0.9944598480048967 * FSCALE, /* exp(-1/180) */ }; /* kernel uses `FSCALE', userland (SHOULD) use kern.fscale */ SYSCTL_INT(_kern, OID_AUTO, fscale, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, FSCALE, ""); static void loadav(void *arg); SDT_PROVIDER_DECLARE(sched); SDT_PROBE_DEFINE(sched, , , preempt); static void sleepinit(void *unused) { hogticks = (hz / 10) * 2; /* Default only. */ init_sleepqueues(); } /* * vmem tries to lock the sleepq mutexes when free'ing kva, so make sure * it is available. */ SYSINIT(sleepinit, SI_SUB_KMEM, SI_ORDER_ANY, sleepinit, 0); /* * General sleep call. Suspends the current thread until a wakeup is * performed on the specified identifier. The thread will then be made * runnable with the specified priority. Sleeps at most sbt units of time * (0 means no timeout). If pri includes the PCATCH flag, let signals * interrupt the sleep, otherwise ignore them while sleeping. Returns 0 if * awakened, EWOULDBLOCK if the timeout expires. If PCATCH is set and a * signal becomes pending, ERESTART is returned if the current system * call should be restarted if possible, and EINTR is returned if the system * call should be interrupted by the signal (return EINTR). * * The lock argument is unlocked before the caller is suspended, and * re-locked before _sleep() returns. If priority includes the PDROP * flag the lock is not re-locked before returning. */ int _sleep(void *ident, struct lock_object *lock, int priority, const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags) { struct thread *td; struct proc *p; struct lock_class *class; uintptr_t lock_state; int catch, pri, rval, sleepq_flags; WITNESS_SAVE_DECL(lock_witness); td = curthread; p = td->td_proc; #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(1, 0, wmesg); #endif WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, lock, "Sleeping on \"%s\"", wmesg); KASSERT(sbt != 0 || mtx_owned(&Giant) || lock != NULL, ("sleeping without a lock")); KASSERT(p != NULL, ("msleep1")); KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep")); if (priority & PDROP) KASSERT(lock != NULL && lock != &Giant.lock_object, ("PDROP requires a non-Giant lock")); if (lock != NULL) class = LOCK_CLASS(lock); else class = NULL; - if (SCHEDULER_STOPPED()) { + if (SCHEDULER_STOPPED_TD(td)) { if (lock != NULL && priority & PDROP) class->lc_unlock(lock); return (0); } catch = priority & PCATCH; pri = priority & PRIMASK; KASSERT(!TD_ON_SLEEPQ(td), ("recursive sleep")); if ((uint8_t *)ident >= &pause_wchan[0] && (uint8_t *)ident <= &pause_wchan[MAXCPU - 1]) sleepq_flags = SLEEPQ_PAUSE; else sleepq_flags = SLEEPQ_SLEEP; if (catch) sleepq_flags |= SLEEPQ_INTERRUPTIBLE; sleepq_lock(ident); CTR5(KTR_PROC, "sleep: thread %ld (pid %ld, %s) on %s (%p)", td->td_tid, p->p_pid, td->td_name, wmesg, ident); if (lock == &Giant.lock_object) mtx_assert(&Giant, MA_OWNED); DROP_GIANT(); if (lock != NULL && lock != &Giant.lock_object && !(class->lc_flags & LC_SLEEPABLE)) { WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); } else /* GCC needs to follow the Yellow Brick Road */ lock_state = -1; /* * We put ourselves on the sleep queue and start our timeout * before calling thread_suspend_check, as we could stop there, * and a wakeup or a SIGCONT (or both) could occur while we were * stopped without resuming us. Thus, we must be ready for sleep * when cursig() is called. If the wakeup happens while we're * stopped, then td will no longer be on a sleep queue upon * return from cursig(). */ sleepq_add(ident, lock, wmesg, sleepq_flags, 0); if (sbt != 0) sleepq_set_timeout_sbt(ident, sbt, pr, flags); if (lock != NULL && class->lc_flags & LC_SLEEPABLE) { sleepq_release(ident); WITNESS_SAVE(lock, lock_witness); lock_state = class->lc_unlock(lock); sleepq_lock(ident); } if (sbt != 0 && catch) rval = sleepq_timedwait_sig(ident, pri); else if (sbt != 0) rval = sleepq_timedwait(ident, pri); else if (catch) rval = sleepq_wait_sig(ident, pri); else { sleepq_wait(ident, pri); rval = 0; } #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, wmesg); #endif PICKUP_GIANT(); if (lock != NULL && lock != &Giant.lock_object && !(priority & PDROP)) { class->lc_lock(lock, lock_state); WITNESS_RESTORE(lock, lock_witness); } return (rval); } int msleep_spin_sbt(void *ident, struct mtx *mtx, const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags) { struct thread *td; struct proc *p; int rval; WITNESS_SAVE_DECL(mtx); td = curthread; p = td->td_proc; KASSERT(mtx != NULL, ("sleeping without a mutex")); KASSERT(p != NULL, ("msleep1")); KASSERT(ident != NULL && TD_IS_RUNNING(td), ("msleep")); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return (0); sleepq_lock(ident); CTR5(KTR_PROC, "msleep_spin: thread %ld (pid %ld, %s) on %s (%p)", td->td_tid, p->p_pid, td->td_name, wmesg, ident); DROP_GIANT(); mtx_assert(mtx, MA_OWNED | MA_NOTRECURSED); WITNESS_SAVE(&mtx->lock_object, mtx); mtx_unlock_spin(mtx); /* * We put ourselves on the sleep queue and start our timeout. */ sleepq_add(ident, &mtx->lock_object, wmesg, SLEEPQ_SLEEP, 0); if (sbt != 0) sleepq_set_timeout_sbt(ident, sbt, pr, flags); /* * Can't call ktrace with any spin locks held so it can lock the * ktrace_mtx lock, and WITNESS_WARN considers it an error to hold * any spin lock. Thus, we have to drop the sleepq spin lock while * we handle those requests. This is safe since we have placed our * thread on the sleep queue already. */ #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) { sleepq_release(ident); ktrcsw(1, 0, wmesg); sleepq_lock(ident); } #endif #ifdef WITNESS sleepq_release(ident); WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "Sleeping on \"%s\"", wmesg); sleepq_lock(ident); #endif if (sbt != 0) rval = sleepq_timedwait(ident, 0); else { sleepq_wait(ident, 0); rval = 0; } #ifdef KTRACE if (KTRPOINT(td, KTR_CSW)) ktrcsw(0, 0, wmesg); #endif PICKUP_GIANT(); mtx_lock_spin(mtx); WITNESS_RESTORE(&mtx->lock_object, mtx); return (rval); } /* * pause() delays the calling thread by the given number of system ticks. * During cold bootup, pause() uses the DELAY() function instead of * the tsleep() function to do the waiting. The "timo" argument must be * greater than or equal to zero. A "timo" value of zero is equivalent * to a "timo" value of one. */ int pause_sbt(const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags) { KASSERT(sbt >= 0, ("pause: timeout must be >= 0")); /* silently convert invalid timeouts */ if (sbt == 0) sbt = tick_sbt; if ((cold && curthread == &thread0) || kdb_active || SCHEDULER_STOPPED()) { /* * We delay one second at a time to avoid overflowing the * system specific DELAY() function(s): */ while (sbt >= SBT_1S) { DELAY(1000000); sbt -= SBT_1S; } /* Do the delay remainder, if any */ sbt = howmany(sbt, SBT_1US); if (sbt > 0) DELAY(sbt); return (0); } return (_sleep(&pause_wchan[curcpu], NULL, 0, wmesg, sbt, pr, flags)); } /* * Make all threads sleeping on the specified identifier runnable. */ void wakeup(void *ident) { int wakeup_swapper; sleepq_lock(ident); wakeup_swapper = sleepq_broadcast(ident, SLEEPQ_SLEEP, 0, 0); sleepq_release(ident); if (wakeup_swapper) { KASSERT(ident != &proc0, ("wakeup and wakeup_swapper and proc0")); kick_proc0(); } } /* * Make a thread sleeping on the specified identifier runnable. * May wake more than one thread if a target thread is currently * swapped out. */ void wakeup_one(void *ident) { int wakeup_swapper; sleepq_lock(ident); wakeup_swapper = sleepq_signal(ident, SLEEPQ_SLEEP, 0, 0); sleepq_release(ident); if (wakeup_swapper) kick_proc0(); } static void kdb_switch(void) { thread_unlock(curthread); kdb_backtrace(); kdb_reenter(); panic("%s: did not reenter debugger", __func__); } /* * The machine independent parts of context switching. */ void mi_switch(int flags, struct thread *newtd) { uint64_t runtime, new_switchtime; struct thread *td; td = curthread; /* XXX */ THREAD_LOCK_ASSERT(td, MA_OWNED | MA_NOTRECURSED); KASSERT(!TD_ON_RUNQ(td), ("mi_switch: called by old code")); #ifdef INVARIANTS if (!TD_ON_LOCK(td) && !TD_IS_RUNNING(td)) mtx_assert(&Giant, MA_NOTOWNED); #endif KASSERT(td->td_critnest == 1 || panicstr, ("mi_switch: switch in a critical section")); KASSERT((flags & (SW_INVOL | SW_VOL)) != 0, ("mi_switch: switch must be voluntary or involuntary")); KASSERT(newtd != curthread, ("mi_switch: preempting back to ourself")); /* * Don't perform context switches from the debugger. */ if (kdb_active) kdb_switch(); - if (SCHEDULER_STOPPED()) + if (SCHEDULER_STOPPED_TD(td)) return; if (flags & SW_VOL) { td->td_ru.ru_nvcsw++; td->td_swvoltick = ticks; } else { td->td_ru.ru_nivcsw++; td->td_swinvoltick = ticks; } #ifdef SCHED_STATS SCHED_STAT_INC(sched_switch_stats[flags & SW_TYPE_MASK]); #endif /* * Compute the amount of time during which the current * thread was running, and add that to its total so far. */ new_switchtime = cpu_ticks(); runtime = new_switchtime - PCPU_GET(switchtime); td->td_runtime += runtime; td->td_incruntime += runtime; PCPU_SET(switchtime, new_switchtime); td->td_generation++; /* bump preempt-detect counter */ PCPU_INC(cnt.v_swtch); PCPU_SET(switchticks, ticks); CTR4(KTR_PROC, "mi_switch: old thread %ld (td_sched %p, pid %ld, %s)", td->td_tid, td_get_sched(td), td->td_proc->p_pid, td->td_name); #if (KTR_COMPILE & KTR_SCHED) != 0 if (TD_IS_IDLETHREAD(td)) KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "idle", "prio:%d", td->td_priority); else KTR_STATE3(KTR_SCHED, "thread", sched_tdname(td), KTDSTATE(td), "prio:%d", td->td_priority, "wmesg:\"%s\"", td->td_wmesg, "lockname:\"%s\"", td->td_lockname); #endif SDT_PROBE0(sched, , , preempt); sched_switch(td, newtd, flags); KTR_STATE1(KTR_SCHED, "thread", sched_tdname(td), "running", "prio:%d", td->td_priority); CTR4(KTR_PROC, "mi_switch: new thread %ld (td_sched %p, pid %ld, %s)", td->td_tid, td_get_sched(td), td->td_proc->p_pid, td->td_name); /* * If the last thread was exiting, finish cleaning it up. */ if ((td = PCPU_GET(deadthread))) { PCPU_SET(deadthread, NULL); thread_stash(td); } } /* * Change thread state to be runnable, placing it on the run queue if * it is in memory. If it is swapped out, return true so our caller * will know to awaken the swapper. */ int setrunnable(struct thread *td) { THREAD_LOCK_ASSERT(td, MA_OWNED); KASSERT(td->td_proc->p_state != PRS_ZOMBIE, ("setrunnable: pid %d is a zombie", td->td_proc->p_pid)); switch (td->td_state) { case TDS_RUNNING: case TDS_RUNQ: return (0); case TDS_INHIBITED: /* * If we are only inhibited because we are swapped out * then arange to swap in this process. Otherwise just return. */ if (td->td_inhibitors != TDI_SWAPPED) return (0); /* FALLTHROUGH */ case TDS_CAN_RUN: break; default: printf("state is 0x%x", td->td_state); panic("setrunnable(2)"); } if ((td->td_flags & TDF_INMEM) == 0) { if ((td->td_flags & TDF_SWAPINREQ) == 0) { td->td_flags |= TDF_SWAPINREQ; return (1); } } else sched_wakeup(td); return (0); } /* * Compute a tenex style load average of a quantity on * 1, 5 and 15 minute intervals. */ static void loadav(void *arg) { int i, nrun; struct loadavg *avg; nrun = sched_load(); avg = &averunnable; for (i = 0; i < 3; i++) avg->ldavg[i] = (cexp[i] * avg->ldavg[i] + nrun * FSCALE * (FSCALE - cexp[i])) >> FSHIFT; /* * Schedule the next update to occur after 5 seconds, but add a * random variation to avoid synchronisation with processes that * run at regular intervals. */ callout_reset_sbt(&loadav_callout, SBT_1US * (4000000 + (int)(random() % 2000001)), SBT_1US, loadav, NULL, C_DIRECT_EXEC | C_PREL(32)); } /* ARGSUSED */ static void synch_setup(void *dummy) { callout_init(&loadav_callout, 1); /* Kick off timeout driven events by calling first time. */ loadav(NULL); } int should_yield(void) { return ((u_int)ticks - (u_int)curthread->td_swvoltick >= hogticks); } void maybe_yield(void) { if (should_yield()) kern_yield(PRI_USER); } void kern_yield(int prio) { struct thread *td; td = curthread; DROP_GIANT(); thread_lock(td); if (prio == PRI_USER) prio = td->td_user_pri; if (prio >= 0) sched_prio(td, prio); mi_switch(SW_VOL | SWT_RELINQUISH, NULL); thread_unlock(td); PICKUP_GIANT(); } /* * General purpose yield system call. */ int sys_yield(struct thread *td, struct yield_args *uap) { thread_lock(td); if (PRI_BASE(td->td_pri_class) == PRI_TIMESHARE) sched_prio(td, PRI_MAX_TIMESHARE); mi_switch(SW_VOL | SWT_RELINQUISH, NULL); thread_unlock(td); td->td_retval[0] = 0; return (0); } Index: stable/11/sys/sys/systm.h =================================================================== --- stable/11/sys/sys/systm.h (revision 315385) +++ stable/11/sys/sys/systm.h (revision 315386) @@ -1,459 +1,463 @@ /*- * Copyright (c) 1982, 1988, 1991, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)systm.h 8.7 (Berkeley) 3/29/95 * $FreeBSD$ */ #ifndef _SYS_SYSTM_H_ #define _SYS_SYSTM_H_ #include #include #include #include #include #include /* for people using printf mainly */ __NULLABILITY_PRAGMA_PUSH extern int cold; /* nonzero if we are doing a cold boot */ extern int suspend_blocked; /* block suspend due to pending shutdown */ extern int rebooting; /* kern_reboot() has been called. */ extern const char *panicstr; /* panic message */ extern char version[]; /* system version */ extern char compiler_version[]; /* compiler version */ extern char copyright[]; /* system copyright */ extern int kstack_pages; /* number of kernel stack pages */ extern u_long pagesizes[]; /* supported page sizes */ extern long physmem; /* physical memory */ extern long realmem; /* 'real' memory */ extern char *rootdevnames[2]; /* names of possible root devices */ extern int boothowto; /* reboot flags, from console subsystem */ extern int bootverbose; /* nonzero to print verbose messages */ extern int maxusers; /* system tune hint */ extern int ngroups_max; /* max # of supplemental groups */ extern int vm_guest; /* Running as virtual machine guest? */ /* * Detected virtual machine guest types. The intention is to expand * and/or add to the VM_GUEST_VM type if specific VM functionality is * ever implemented (e.g. vendor-specific paravirtualization features). * Keep in sync with vm_guest_sysctl_names[]. */ enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV, VM_GUEST_VMWARE, VM_GUEST_KVM, VM_LAST }; #if defined(WITNESS) || defined(INVARIANT_SUPPORT) void kassert_panic(const char *fmt, ...) __printflike(1, 2); #endif #ifdef INVARIANTS /* The option is always available */ #define KASSERT(exp,msg) do { \ if (__predict_false(!(exp))) \ kassert_panic msg; \ } while (0) #define VNASSERT(exp, vp, msg) do { \ if (__predict_false(!(exp))) { \ vn_printf(vp, "VNASSERT failed\n"); \ kassert_panic msg; \ } \ } while (0) #else #define KASSERT(exp,msg) do { \ } while (0) #define VNASSERT(exp, vp, msg) do { \ } while (0) #endif #ifndef CTASSERT /* Allow lint to override */ #define CTASSERT(x) _Static_assert(x, "compile-time assertion failed") #endif /* * Assert that a pointer can be loaded from memory atomically. * * This assertion enforces stronger alignment than necessary. For example, * on some architectures, atomicity for unaligned loads will depend on * whether or not the load spans multiple cache lines. */ #define ASSERT_ATOMIC_LOAD_PTR(var, msg) \ KASSERT(sizeof(var) == sizeof(void *) && \ ((uintptr_t)&(var) & (sizeof(void *) - 1)) == 0, msg) /* * Assert that a thread is in critical(9) section. */ #define CRITICAL_ASSERT(td) \ KASSERT((td)->td_critnest >= 1, ("Not in critical section")); /* * If we have already panic'd and this is the thread that called * panic(), then don't block on any mutexes but silently succeed. * Otherwise, the kernel will deadlock since the scheduler isn't * going to run the thread that holds any lock we need. */ -#define SCHEDULER_STOPPED() __predict_false(curthread->td_stopsched) +#define SCHEDULER_STOPPED_TD(td) ({ \ + MPASS((td) == curthread); \ + __predict_false((td)->td_stopsched); \ +}) +#define SCHEDULER_STOPPED() SCHEDULER_STOPPED_TD(curthread) /* * Align variables. */ #define __read_mostly __section(".data.read_mostly") #define __exclusive_cache_line __aligned(CACHE_LINE_SIZE) \ __section(".data.exclusive_cache_line") /* * XXX the hints declarations are even more misplaced than most declarations * in this file, since they are needed in one file (per arch) and only used * in two files. * XXX most of these variables should be const. */ extern int osreldate; extern int envmode; extern int hintmode; /* 0 = off. 1 = config, 2 = fallback */ extern int dynamic_kenv; extern struct mtx kenv_lock; extern char *kern_envp; extern char static_env[]; extern char static_hints[]; /* by config for now */ extern char **kenvp; extern const void *zero_region; /* address space maps to a zeroed page */ extern int unmapped_buf_allowed; #ifdef __LP64__ #define IOSIZE_MAX iosize_max() #define DEVFS_IOSIZE_MAX devfs_iosize_max() #else #define IOSIZE_MAX SSIZE_MAX #define DEVFS_IOSIZE_MAX SSIZE_MAX #endif /* * General function declarations. */ struct inpcb; struct lock_object; struct malloc_type; struct mtx; struct proc; struct socket; struct thread; struct tty; struct ucred; struct uio; struct _jmp_buf; struct trapframe; struct eventtimer; int setjmp(struct _jmp_buf *) __returns_twice; void longjmp(struct _jmp_buf *, int) __dead2; int dumpstatus(vm_offset_t addr, off_t count); int nullop(void); int eopnotsupp(void); int ureadc(int, struct uio *); void hashdestroy(void *, struct malloc_type *, u_long); void *hashinit(int count, struct malloc_type *type, u_long *hashmask); void *hashinit_flags(int count, struct malloc_type *type, u_long *hashmask, int flags); #define HASH_NOWAIT 0x00000001 #define HASH_WAITOK 0x00000002 void *phashinit(int count, struct malloc_type *type, u_long *nentries); void *phashinit_flags(int count, struct malloc_type *type, u_long *nentries, int flags); void g_waitidle(void); void panic(const char *, ...) __dead2 __printflike(1, 2); void vpanic(const char *, __va_list) __dead2 __printflike(1, 0); void cpu_boot(int); void cpu_flush_dcache(void *, size_t); void cpu_rootconf(void); void critical_enter(void); void critical_exit(void); void init_param1(void); void init_param2(long physpages); void init_static_kenv(char *, size_t); void tablefull(const char *); #ifdef EARLY_PRINTF typedef void early_putc_t(int ch); extern early_putc_t *early_putc; #endif int kvprintf(char const *, void (*)(int, void*), void *, int, __va_list) __printflike(1, 0); void log(int, const char *, ...) __printflike(2, 3); void log_console(struct uio *); void vlog(int, const char *, __va_list) __printflike(2, 0); int asprintf(char **ret, struct malloc_type *mtp, const char *format, ...) __printflike(3, 4); int printf(const char *, ...) __printflike(1, 2); int snprintf(char *, size_t, const char *, ...) __printflike(3, 4); int sprintf(char *buf, const char *, ...) __printflike(2, 3); int uprintf(const char *, ...) __printflike(1, 2); int vprintf(const char *, __va_list) __printflike(1, 0); int vasprintf(char **ret, struct malloc_type *mtp, const char *format, __va_list ap) __printflike(3, 0); int vsnprintf(char *, size_t, const char *, __va_list) __printflike(3, 0); int vsnrprintf(char *, size_t, int, const char *, __va_list) __printflike(4, 0); int vsprintf(char *buf, const char *, __va_list) __printflike(2, 0); int ttyprintf(struct tty *, const char *, ...) __printflike(2, 3); int sscanf(const char *, char const * _Nonnull, ...) __scanflike(2, 3); int vsscanf(const char * _Nonnull, char const * _Nonnull, __va_list) __scanflike(2, 0); long strtol(const char *, char **, int); u_long strtoul(const char *, char **, int); quad_t strtoq(const char *, char **, int); u_quad_t strtouq(const char *, char **, int); void tprintf(struct proc *p, int pri, const char *, ...) __printflike(3, 4); void vtprintf(struct proc *, int, const char *, __va_list) __printflike(3, 0); void hexdump(const void *ptr, int length, const char *hdr, int flags); #define HD_COLUMN_MASK 0xff #define HD_DELIM_MASK 0xff00 #define HD_OMIT_COUNT (1 << 16) #define HD_OMIT_HEX (1 << 17) #define HD_OMIT_CHARS (1 << 18) #define ovbcopy(f, t, l) bcopy((f), (t), (l)) void bcopy(const void * _Nonnull from, void * _Nonnull to, size_t len); void bzero(void * _Nonnull buf, size_t len); void explicit_bzero(void * _Nonnull, size_t); void *memcpy(void * _Nonnull to, const void * _Nonnull from, size_t len); void *memmove(void * _Nonnull dest, const void * _Nonnull src, size_t n); int copystr(const void * _Nonnull __restrict kfaddr, void * _Nonnull __restrict kdaddr, size_t len, size_t * __restrict lencopied); int copyinstr(const void * __restrict udaddr, void * _Nonnull __restrict kaddr, size_t len, size_t * __restrict lencopied); int copyin(const void * _Nonnull __restrict udaddr, void * _Nonnull __restrict kaddr, size_t len); int copyin_nofault(const void * _Nonnull __restrict udaddr, void * _Nonnull __restrict kaddr, size_t len); int copyout(const void * _Nonnull __restrict kaddr, void * _Nonnull __restrict udaddr, size_t len); int copyout_nofault(const void * _Nonnull __restrict kaddr, void * _Nonnull __restrict udaddr, size_t len); int fubyte(volatile const void *base); long fuword(volatile const void *base); int fuword16(volatile const void *base); int32_t fuword32(volatile const void *base); int64_t fuword64(volatile const void *base); int fueword(volatile const void *base, long *val); int fueword32(volatile const void *base, int32_t *val); int fueword64(volatile const void *base, int64_t *val); int subyte(volatile void *base, int byte); int suword(volatile void *base, long word); int suword16(volatile void *base, int word); int suword32(volatile void *base, int32_t word); int suword64(volatile void *base, int64_t word); uint32_t casuword32(volatile uint32_t *base, uint32_t oldval, uint32_t newval); u_long casuword(volatile u_long *p, u_long oldval, u_long newval); int casueword32(volatile uint32_t *base, uint32_t oldval, uint32_t *oldvalp, uint32_t newval); int casueword(volatile u_long *p, u_long oldval, u_long *oldvalp, u_long newval); void realitexpire(void *); int sysbeep(int hertz, int period); void hardclock(int usermode, uintfptr_t pc); void hardclock_cnt(int cnt, int usermode); void hardclock_cpu(int usermode); void hardclock_sync(int cpu); void softclock(void *); void statclock(int usermode); void statclock_cnt(int cnt, int usermode); void profclock(int usermode, uintfptr_t pc); void profclock_cnt(int cnt, int usermode, uintfptr_t pc); int hardclockintr(void); void startprofclock(struct proc *); void stopprofclock(struct proc *); void cpu_startprofclock(void); void cpu_stopprofclock(void); sbintime_t cpu_idleclock(void); void cpu_activeclock(void); void cpu_new_callout(int cpu, sbintime_t bt, sbintime_t bt_opt); void cpu_et_frequency(struct eventtimer *et, uint64_t newfreq); extern int cpu_disable_c2_sleep; extern int cpu_disable_c3_sleep; int cr_cansee(struct ucred *u1, struct ucred *u2); int cr_canseesocket(struct ucred *cred, struct socket *so); int cr_canseeinpcb(struct ucred *cred, struct inpcb *inp); char *kern_getenv(const char *name); void freeenv(char *env); int getenv_int(const char *name, int *data); int getenv_uint(const char *name, unsigned int *data); int getenv_long(const char *name, long *data); int getenv_ulong(const char *name, unsigned long *data); int getenv_string(const char *name, char *data, int size); int getenv_int64(const char *name, int64_t *data); int getenv_uint64(const char *name, uint64_t *data); int getenv_quad(const char *name, quad_t *data); int kern_setenv(const char *name, const char *value); int kern_unsetenv(const char *name); int testenv(const char *name); typedef uint64_t (cpu_tick_f)(void); void set_cputicker(cpu_tick_f *func, uint64_t freq, unsigned var); extern cpu_tick_f *cpu_ticks; uint64_t cpu_tickrate(void); uint64_t cputick2usec(uint64_t tick); #ifdef APM_FIXUP_CALLTODO struct timeval; void adjust_timeout_calltodo(struct timeval *time_change); #endif /* APM_FIXUP_CALLTODO */ #include /* Initialize the world */ void consinit(void); void cpu_initclocks(void); void cpu_initclocks_bsp(void); void cpu_initclocks_ap(void); void usrinfoinit(void); /* Finalize the world */ void kern_reboot(int) __dead2; void shutdown_nice(int); /* Timeouts */ typedef void timeout_t(void *); /* timeout function type */ #define CALLOUT_HANDLE_INITIALIZER(handle) \ { NULL } void callout_handle_init(struct callout_handle *); struct callout_handle timeout(timeout_t *, void *, int); void untimeout(timeout_t *, void *, struct callout_handle); /* Stubs for obsolete functions that used to be for interrupt management */ static __inline intrmask_t splbio(void) { return 0; } static __inline intrmask_t splcam(void) { return 0; } static __inline intrmask_t splclock(void) { return 0; } static __inline intrmask_t splhigh(void) { return 0; } static __inline intrmask_t splimp(void) { return 0; } static __inline intrmask_t splnet(void) { return 0; } static __inline intrmask_t spltty(void) { return 0; } static __inline void splx(intrmask_t ipl __unused) { return; } /* * Common `proc' functions are declared here so that proc.h can be included * less often. */ int _sleep(void * _Nonnull chan, struct lock_object *lock, int pri, const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags); #define msleep(chan, mtx, pri, wmesg, timo) \ _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), \ tick_sbt * (timo), 0, C_HARDCLOCK) #define msleep_sbt(chan, mtx, pri, wmesg, bt, pr, flags) \ _sleep((chan), &(mtx)->lock_object, (pri), (wmesg), (bt), (pr), \ (flags)) int msleep_spin_sbt(void * _Nonnull chan, struct mtx *mtx, const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags); #define msleep_spin(chan, mtx, wmesg, timo) \ msleep_spin_sbt((chan), (mtx), (wmesg), tick_sbt * (timo), \ 0, C_HARDCLOCK) int pause_sbt(const char *wmesg, sbintime_t sbt, sbintime_t pr, int flags); #define pause(wmesg, timo) \ pause_sbt((wmesg), tick_sbt * (timo), 0, C_HARDCLOCK) #define tsleep(chan, pri, wmesg, timo) \ _sleep((chan), NULL, (pri), (wmesg), tick_sbt * (timo), \ 0, C_HARDCLOCK) #define tsleep_sbt(chan, pri, wmesg, bt, pr, flags) \ _sleep((chan), NULL, (pri), (wmesg), (bt), (pr), (flags)) void wakeup(void * chan); void wakeup_one(void * chan); /* * Common `struct cdev *' stuff are declared here to avoid #include poisoning */ struct cdev; dev_t dev2udev(struct cdev *x); const char *devtoname(struct cdev *cdev); #ifdef __LP64__ size_t devfs_iosize_max(void); size_t iosize_max(void); #endif int poll_no_poll(int events); /* XXX: Should be void nanodelay(u_int nsec); */ void DELAY(int usec); /* Root mount holdback API */ struct root_hold_token; struct root_hold_token *root_mount_hold(const char *identifier); void root_mount_rel(struct root_hold_token *h); int root_mounted(void); /* * Unit number allocation API. (kern/subr_unit.c) */ struct unrhdr; struct unrhdr *new_unrhdr(int low, int high, struct mtx *mutex); void init_unrhdr(struct unrhdr *uh, int low, int high, struct mtx *mutex); void delete_unrhdr(struct unrhdr *uh); void clean_unrhdr(struct unrhdr *uh); void clean_unrhdrl(struct unrhdr *uh); int alloc_unr(struct unrhdr *uh); int alloc_unr_specific(struct unrhdr *uh, u_int item); int alloc_unrl(struct unrhdr *uh); void free_unr(struct unrhdr *uh, u_int item); void intr_prof_stack_use(struct thread *td, struct trapframe *frame); void counted_warning(unsigned *counter, const char *msg); __NULLABILITY_PRAGMA_POP #endif /* !_SYS_SYSTM_H_ */ Index: stable/11 =================================================================== --- stable/11 (revision 315385) +++ stable/11 (revision 315386) Property changes on: stable/11 ___________________________________________________________________ Modified: svn:mergeinfo ## -0,0 +0,1 ## Merged /head:r313853,313859