diff options
Diffstat (limited to 'sys/kern/subr_sleepqueue.c')
| -rw-r--r-- | sys/kern/subr_sleepqueue.c | 45 |
1 files changed, 31 insertions, 14 deletions
diff --git a/sys/kern/subr_sleepqueue.c b/sys/kern/subr_sleepqueue.c index 7e86e227b1b4..eeb88594c570 100644 --- a/sys/kern/subr_sleepqueue.c +++ b/sys/kern/subr_sleepqueue.c @@ -113,8 +113,8 @@ struct sleepqueue { LIST_ENTRY(sleepqueue) sq_hash; /* (c) Chain and free list. */ LIST_HEAD(, sleepqueue) sq_free; /* (c) Free queues. */ void *sq_wchan; /* (c) Wait channel. */ - int sq_type; /* (c) Queue type. */ #ifdef INVARIANTS + int sq_type; /* (c) Queue type. */ struct mtx *sq_lock; /* (c) Associated lock. */ #endif }; @@ -208,9 +208,21 @@ sleepq_free(struct sleepqueue *sq) } /* + * Lock the sleep queue chain associated with the specified wait channel. + */ +void +sleepq_lock(void *wchan) +{ + struct sleepqueue_chain *sc; + + sc = SC_LOOKUP(wchan); + mtx_lock_spin(&sc->sc_lock); +} + +/* * Look up the sleep queue associated with a given wait channel in the hash - * table locking the associated sleep queue chain. Return holdind the sleep - * queue chain lock. If no queue is found in the table, NULL is returned. + * table locking the associated sleep queue chain. If no queue is found in + * the table, NULL is returned. */ struct sleepqueue * sleepq_lookup(void *wchan) @@ -220,7 +232,7 @@ sleepq_lookup(void *wchan) KASSERT(wchan != NULL, ("%s: invalid NULL wait channel", __func__)); sc = SC_LOOKUP(wchan); - mtx_lock_spin(&sc->sc_lock); + mtx_assert(&sc->sc_lock, MA_OWNED); LIST_FOREACH(sq, &sc->sc_queues, sq_hash) if (sq->sq_wchan == wchan) return (sq); @@ -246,10 +258,10 @@ sleepq_release(void *wchan) * woken up. */ void -sleepq_add(struct sleepqueue *sq, void *wchan, struct mtx *lock, - const char *wmesg, int flags) +sleepq_add(void *wchan, struct mtx *lock, const char *wmesg, int flags) { struct sleepqueue_chain *sc; + struct sleepqueue *sq; struct thread *td, *td1; td = curthread; @@ -258,7 +270,14 @@ sleepq_add(struct sleepqueue *sq, void *wchan, struct mtx *lock, MPASS(td->td_sleepqueue != NULL); MPASS(wchan != NULL); - /* If the passed in sleep queue is NULL, use this thread's queue. */ + /* Look up the sleep queue associated with the wait channel 'wchan'. */ + sq = sleepq_lookup(wchan); + + /* + * If the wait channel does not already have a sleep queue, use + * this thread's sleep queue. Otherwise, insert the current thread + * into the sleep queue already in use by this wait channel. + */ if (sq == NULL) { #ifdef SLEEPQUEUE_PROFILING sc->sc_depth++; @@ -278,12 +297,13 @@ sleepq_add(struct sleepqueue *sq, void *wchan, struct mtx *lock, sq->sq_wchan = wchan; #ifdef INVARIANTS sq->sq_lock = lock; -#endif sq->sq_type = flags & SLEEPQ_TYPE; +#endif TAILQ_INSERT_TAIL(&sq->sq_blocked, td, td_slpq); } else { MPASS(wchan == sq->sq_wchan); MPASS(lock == sq->sq_lock); + MPASS((flags & SLEEPQ_TYPE) == sq->sq_type); TAILQ_FOREACH(td1, &sq->sq_blocked, td_slpq) if (td1->td_priority > td->td_priority) break; @@ -368,6 +388,7 @@ sleepq_catch_signals(void *wchan) * thread was removed from the sleep queue while we were blocked * above, then clear TDF_SINTR before returning. */ + sleepq_lock(wchan); sq = sleepq_lookup(wchan); mtx_lock_spin(&sched_lock); if (TD_ON_SLEEPQ(td) && (sig != 0 || do_upcall != 0)) { @@ -665,9 +686,6 @@ sleepq_signal(void *wchan, int flags, int pri) } KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), ("%s: mismatch between sleep/wakeup and cv_*", __func__)); - /* XXX: Do for all sleep queues eventually. */ - if (flags & SLEEPQ_CONDVAR) - mtx_assert(sq->sq_lock, MA_OWNED); /* Remove first thread from queue and awaken it. */ td = TAILQ_FIRST(&sq->sq_blocked); @@ -695,9 +713,6 @@ sleepq_broadcast(void *wchan, int flags, int pri) } KASSERT(sq->sq_type == (flags & SLEEPQ_TYPE), ("%s: mismatch between sleep/wakeup and cv_*", __func__)); - /* XXX: Do for all sleep queues eventually. */ - if (flags & SLEEPQ_CONDVAR) - mtx_assert(sq->sq_lock, MA_OWNED); /* Move blocked threads from the sleep queue to a temporary list. */ TAILQ_INIT(&list); @@ -739,6 +754,7 @@ sleepq_timeout(void *arg) if (TD_ON_SLEEPQ(td)) { wchan = td->td_wchan; mtx_unlock_spin(&sched_lock); + sleepq_lock(wchan); sq = sleepq_lookup(wchan); mtx_lock_spin(&sched_lock); } else { @@ -802,6 +818,7 @@ sleepq_remove(struct thread *td, void *wchan) * bail. */ MPASS(wchan != NULL); + sleepq_lock(wchan); sq = sleepq_lookup(wchan); mtx_lock_spin(&sched_lock); if (!TD_ON_SLEEPQ(td) || td->td_wchan != wchan) { |