diff options
author | jhb <jhb@FreeBSD.org> | 2001-05-17 22:43:26 +0000 |
---|---|---|
committer | jhb <jhb@FreeBSD.org> | 2001-05-17 22:43:26 +0000 |
commit | 7d561540988609998b733af982b2caaa753867c2 (patch) | |
tree | 9232b16931a2d03c2e4bf0ebe70d5ba80cfb6a07 /sys/kern/kern_intr.c | |
parent | 59ffccfbd6932c90e77e70ea73d3b8afea0998ba (diff) | |
download | FreeBSD-src-7d561540988609998b733af982b2caaa753867c2.zip FreeBSD-src-7d561540988609998b733af982b2caaa753867c2.tar.gz |
- Remove the global ithread_list_lock spin lock in favor of per-ithread
sleep locks.
- Delay returning from ithread_remove_handler() until we are certain that
the interrupt handler being removed has in fact been removed from the
ithread.
- XXX: There is still a problem in that nothing protects the kernel from
adding a new handler while the ithread is running, though with our
current architectures this is not a problem.
Requested by: gibbs (2)
Diffstat (limited to 'sys/kern/kern_intr.c')
-rw-r--r-- | sys/kern/kern_intr.c | 67 |
1 files changed, 30 insertions, 37 deletions
diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c index f8f6c1a..5b376c1 100644 --- a/sys/kern/kern_intr.c +++ b/sys/kern/kern_intr.c @@ -62,13 +62,10 @@ void *softclock_ih; struct ithd *clk_ithd; struct ithd *tty_ithd; -static struct mtx ithread_list_lock; - static MALLOC_DEFINE(M_ITHREAD, "ithread", "Interrupt Threads"); static void ithread_update(struct ithd *); static void ithread_loop(void *); -static void ithread_init(void *); static void start_softintr(void *); static void swi_net(void *); @@ -120,6 +117,7 @@ ithread_update(struct ithd *ithd) struct proc *p; int entropy; + mtx_assert(&ithd->it_lock, MA_OWNED); p = ithd->it_proc; if (p == NULL) return; @@ -178,6 +176,8 @@ ithread_create(struct ithd **ithread, int vector, int flags, ithd->it_enable = enable; ithd->it_flags = flags; TAILQ_INIT(&ithd->it_handlers); + mtx_init(&ithd->it_lock, "ithread", MTX_DEF); + mtx_lock(&ithd->it_lock); va_start(ap, fmt); vsnprintf(ithd->it_name, sizeof(ithd->it_name), fmt, ap); @@ -186,6 +186,7 @@ ithread_create(struct ithd **ithread, int vector, int flags, error = kthread_create(ithread_loop, ithd, &p, RFSTOPPED | RFHIGHPID, "%s", ithd->it_name); if (error) { + mtx_destroy(&ithd->it_lock); free(ithd, M_ITHREAD); return (error); } @@ -196,6 +197,7 @@ ithread_create(struct ithd **ithread, int vector, int flags, p->p_ithd = ithd; if (ithread != NULL) *ithread = ithd; + mtx_unlock(&ithd->it_lock); CTR1(KTR_INTR, __func__ ": created %s", ithd->it_name); return (0); @@ -205,16 +207,22 @@ int ithread_destroy(struct ithd *ithread) { - if (ithread == NULL || !TAILQ_EMPTY(&ithread->it_handlers)) + if (ithread == NULL) return (EINVAL); - mtx_lock_spin(&sched_lock); + mtx_lock(&ithread->it_lock); + if (!TAILQ_EMPTY(&ithread->it_handlers)) { + mtx_unlock(&ithread->it_lock); + return (EINVAL); + } ithread->it_flags |= IT_DEAD; + mtx_lock_spin(&sched_lock); if (ithread->it_proc->p_stat == SWAIT) { ithread->it_proc->p_stat = SRUN; setrunqueue(ithread->it_proc); } mtx_unlock_spin(&sched_lock); + mtx_unlock(&ithread->it_lock); CTR1(KTR_INTR, __func__ ": killing %s", ithread->it_name); return (0); } @@ -246,7 +254,7 @@ ithread_add_handler(struct ithd* ithread, const char *name, if (flags & INTR_ENTROPY) ih->ih_flags |= IH_ENTROPY; - mtx_lock_spin(&ithread_list_lock); + mtx_lock(&ithread->it_lock); if ((flags & INTR_EXCL) !=0 && !TAILQ_EMPTY(&ithread->it_handlers)) goto fail; if (!TAILQ_EMPTY(&ithread->it_handlers) && @@ -261,7 +269,7 @@ ithread_add_handler(struct ithd* ithread, const char *name, else TAILQ_INSERT_BEFORE(temp_ih, ih, ih_next); ithread_update(ithread); - mtx_unlock_spin(&ithread_list_lock); + mtx_unlock(&ithread->it_lock); if (cookiep != NULL) *cookiep = ih; @@ -270,7 +278,7 @@ ithread_add_handler(struct ithd* ithread, const char *name, return (0); fail: - mtx_unlock_spin(&ithread_list_lock); + mtx_unlock(&ithread->it_lock); free(ih, M_ITHREAD); return (EINVAL); } @@ -292,12 +300,12 @@ ithread_remove_handler(void *cookie) handler->ih_name)); CTR2(KTR_INTR, __func__ ": removing %s from %s", handler->ih_name, ithread->it_name); - mtx_lock_spin(&ithread_list_lock); + mtx_lock(&ithread->it_lock); #ifdef INVARIANTS TAILQ_FOREACH(ih, &ithread->it_handlers, ih_next) if (ih == handler) goto ok; - mtx_unlock_spin(&ithread_list_lock); + mtx_unlock(&ithread->it_lock); panic("interrupt handler \"%s\" not found in interrupt thread \"%s\"", ih->ih_name, ithread->it_name); ok: @@ -316,15 +324,14 @@ ok: * it on the list. */ ithread->it_need = 1; - } else { + } else TAILQ_REMOVE(&ithread->it_handlers, handler, ih_next); - ithread_update(ithread); - } mtx_unlock_spin(&sched_lock); - mtx_unlock_spin(&ithread_list_lock); - - if ((handler->ih_flags & IH_DEAD) == 0) - free(handler, M_ITHREAD); + if ((handler->ih_flags & IH_DEAD) != 0) + msleep(handler, &ithread->it_lock, PUSER, "itrmh", 0); + ithread_update(ithread); + mtx_unlock(&ithread->it_lock); + free(handler, M_ITHREAD); return (0); } @@ -473,6 +480,7 @@ ithread_loop(void *arg) CTR2(KTR_INTR, __func__ ": pid %d: (%s) exiting", p->p_pid, p->p_comm); p->p_ithd = NULL; + mtx_destroy(&ithd->it_lock); mtx_lock(&Giant); free(ithd, M_ITHREAD); kthread_exit(0); @@ -499,20 +507,16 @@ restart: (void *)ih->ih_handler, ih->ih_argument, ih->ih_flags); - if ((ih->ih_flags & IH_MPSAFE) == 0) - mtx_lock(&Giant); if ((ih->ih_flags & IH_DEAD) != 0) { - mtx_lock_spin(&ithread_list_lock); + mtx_lock(&ithd->it_lock); TAILQ_REMOVE(&ithd->it_handlers, ih, ih_next); - ithread_update(ithd); - mtx_unlock_spin(&ithread_list_lock); - if (!mtx_owned(&Giant)) - mtx_lock(&Giant); - free(ih, M_ITHREAD); - mtx_unlock(&Giant); + wakeup(ih); + mtx_unlock(&ithd->it_lock); goto restart; } + if ((ih->ih_flags & IH_MPSAFE) == 0) + mtx_lock(&Giant); ih->ih_handler(ih->ih_argument); if ((ih->ih_flags & IH_MPSAFE) == 0) mtx_unlock(&Giant); @@ -542,17 +546,6 @@ restart: } /* - * Initialize mutex used to protect ithread handler lists. - */ -static void -ithread_init(void *dummy) -{ - - mtx_init(&ithread_list_lock, "ithread list lock", MTX_SPIN); -} -SYSINIT(ithread_init, SI_SUB_INTR, SI_ORDER_FIRST, ithread_init, NULL); - -/* * Start standard software interrupt threads */ static void |