diff options
author | davidxu <davidxu@FreeBSD.org> | 2005-03-05 09:15:03 +0000 |
---|---|---|
committer | davidxu <davidxu@FreeBSD.org> | 2005-03-05 09:15:03 +0000 |
commit | 07ae169b7fba1fbbb585f89bdec3b0d3a8935eaa (patch) | |
tree | dedc940c7a14684c89066263b32e64ffefc35572 /sys/kern/kern_umtx.c | |
parent | 17a55ed17fb5c8e6a2f7669f03835a83b4d4d211 (diff) | |
download | FreeBSD-src-07ae169b7fba1fbbb585f89bdec3b0d3a8935eaa.zip FreeBSD-src-07ae169b7fba1fbbb585f89bdec3b0d3a8935eaa.tar.gz |
Allocate umtx_q from heap instead of stack, this avoids
page fault panic in kernel under heavy swapping.
Diffstat (limited to 'sys/kern/kern_umtx.c')
-rw-r--r-- | sys/kern/kern_umtx.c | 80 |
1 files changed, 46 insertions, 34 deletions
diff --git a/sys/kern/kern_umtx.c b/sys/kern/kern_umtx.c index 31a5cb1..c159487 100644 --- a/sys/kern/kern_umtx.c +++ b/sys/kern/kern_umtx.c @@ -119,6 +119,18 @@ static void umtx_key_release(struct umtx_key *key); SYSINIT(umtx, SI_SUB_EVENTHANDLER+1, SI_ORDER_MIDDLE, umtxq_init_chains, NULL); +struct umtx_q * +umtxq_alloc(void) +{ + return (malloc(sizeof(struct umtx_q), M_UMTX, M_WAITOK)); +} + +void +umtxq_free(struct umtx_q *uq) +{ + free(uq, M_UMTX); +} + static void umtxq_init_chains(void *arg __unused) { @@ -210,7 +222,6 @@ umtxq_insert(struct umtx_q *uq) mtx_assert(umtxq_mtx(chain), MA_OWNED); head = &umtxq_chains[chain].uc_queue; LIST_INSERT_HEAD(head, uq, uq_next); - uq->uq_thread->td_umtxq = uq; mtx_lock_spin(&sched_lock); uq->uq_thread->td_flags |= TDF_UMTXQ; mtx_unlock_spin(&sched_lock); @@ -225,7 +236,6 @@ umtxq_remove(struct umtx_q *uq) mtx_assert(umtxq_mtx(umtxq_hash(&uq->uq_key)), MA_OWNED); if (uq->uq_thread->td_flags & TDF_UMTXQ) { LIST_REMOVE(uq, uq_next); - uq->uq_thread->td_umtxq = NULL; /* turning off TDF_UMTXQ should be the last thing. */ mtx_lock_spin(&sched_lock); uq->uq_thread->td_flags &= ~TDF_UMTXQ; @@ -434,11 +444,12 @@ fork_handler(void *arg, struct proc *p1, struct proc *p2, int flags) static int _do_lock(struct thread *td, struct umtx *umtx, long id, int timo) { - struct umtx_q uq; + struct umtx_q *uq; intptr_t owner; intptr_t old; int error = 0; + uq = td->td_umtxq; /* * Care must be exercised when dealing with umtx structure. It * can fault on any access. @@ -479,7 +490,7 @@ _do_lock(struct thread *td, struct umtx *umtx, long id, int timo) * If we caught a signal, we have retried and now * exit immediately. */ - if (error || (error = umtxq_queue_me(td, umtx, &uq)) != 0) + if (error || (error = umtxq_queue_me(td, umtx, uq)) != 0) return (error); /* @@ -493,12 +504,12 @@ _do_lock(struct thread *td, struct umtx *umtx, long id, int timo) /* The address was invalid. */ if (old == -1) { - umtxq_lock(&uq.uq_key); - umtxq_busy(&uq.uq_key); - umtxq_remove(&uq); - umtxq_unbusy(&uq.uq_key); - umtxq_unlock(&uq.uq_key); - umtx_key_release(&uq.uq_key); + umtxq_lock(&uq->uq_key); + umtxq_busy(&uq->uq_key); + umtxq_remove(uq); + umtxq_unbusy(&uq->uq_key); + umtxq_unlock(&uq->uq_key); + umtx_key_release(&uq->uq_key); return (EFAULT); } @@ -507,17 +518,17 @@ _do_lock(struct thread *td, struct umtx *umtx, long id, int timo) * and we need to retry or we lost a race to the thread * unlocking the umtx. */ - umtxq_lock(&uq.uq_key); + umtxq_lock(&uq->uq_key); if (old == owner && (td->td_flags & TDF_UMTXQ)) { - error = umtxq_sleep(td, &uq.uq_key, + error = umtxq_sleep(td, &uq->uq_key, td->td_priority | PCATCH, "umtx", timo); } - umtxq_busy(&uq.uq_key); - umtxq_remove(&uq); - umtxq_unbusy(&uq.uq_key); - umtxq_unlock(&uq.uq_key); - umtx_key_release(&uq.uq_key); + umtxq_busy(&uq->uq_key); + umtxq_remove(uq); + umtxq_unbusy(&uq->uq_key); + umtxq_unlock(&uq->uq_key); + umtx_key_release(&uq->uq_key); } return (0); @@ -614,45 +625,46 @@ do_unlock(struct thread *td, struct umtx *umtx, long id) static int do_wait(struct thread *td, struct umtx *umtx, long id, struct timespec *timeout) { - struct umtx_q uq; + struct umtx_q *uq; struct timespec ts, ts2, ts3; struct timeval tv; long tmp; int error = 0; - if ((error = umtxq_queue_me(td, umtx, &uq)) != 0) + uq = td->td_umtxq; + if ((error = umtxq_queue_me(td, umtx, uq)) != 0) return (error); tmp = fuword(&umtx->u_owner); if (tmp != id) { - umtxq_lock(&uq.uq_key); - umtxq_remove(&uq); - umtxq_unlock(&uq.uq_key); + umtxq_lock(&uq->uq_key); + umtxq_remove(uq); + umtxq_unlock(&uq->uq_key); } else if (timeout == NULL) { - umtxq_lock(&uq.uq_key); + umtxq_lock(&uq->uq_key); if (td->td_flags & TDF_UMTXQ) - error = umtxq_sleep(td, &uq.uq_key, + error = umtxq_sleep(td, &uq->uq_key, td->td_priority | PCATCH, "ucond", 0); if (!(td->td_flags & TDF_UMTXQ)) error = 0; else - umtxq_remove(&uq); - umtxq_unlock(&uq.uq_key); + umtxq_remove(uq); + umtxq_unlock(&uq->uq_key); } else { getnanouptime(&ts); timespecadd(&ts, timeout); TIMESPEC_TO_TIMEVAL(&tv, timeout); for (;;) { - umtxq_lock(&uq.uq_key); + umtxq_lock(&uq->uq_key); if (td->td_flags & TDF_UMTXQ) { - error = umtxq_sleep(td, &uq.uq_key, + error = umtxq_sleep(td, &uq->uq_key, td->td_priority | PCATCH, "ucond", tvtohz(&tv)); } if (!(td->td_flags & TDF_UMTXQ)) { - umtxq_unlock(&uq.uq_key); + umtxq_unlock(&uq->uq_key); goto out; } - umtxq_unlock(&uq.uq_key); + umtxq_unlock(&uq->uq_key); if (error != ETIMEDOUT) break; getnanouptime(&ts2); @@ -664,12 +676,12 @@ do_wait(struct thread *td, struct umtx *umtx, long id, struct timespec *timeout) timespecsub(&ts3, &ts2); TIMESPEC_TO_TIMEVAL(&tv, &ts3); } - umtxq_lock(&uq.uq_key); - umtxq_remove(&uq); - umtxq_unlock(&uq.uq_key); + umtxq_lock(&uq->uq_key); + umtxq_remove(uq); + umtxq_unlock(&uq->uq_key); } out: - umtx_key_release(&uq.uq_key); + umtx_key_release(&uq->uq_key); if (error == ERESTART) error = EINTR; return (error); |