Date: Thu, 15 Aug 2024 14:29:57 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 665b21f583e8 - stable/14 - intr: Remove dead code from intr_event_remove_handler() Message-ID: <202408151429.47FETv8u016633@gitrepo.freebsd.org>
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The branch stable/14 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=665b21f583e8066df90e9e07d66657ddd8a02a53 commit 665b21f583e8066df90e9e07d66657ddd8a02a53 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2024-07-30 14:35:53 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2024-08-15 14:29:49 +0000 intr: Remove dead code from intr_event_remove_handler() We currently destroy the ithread in intr_event_destroy(). In preparation for fixing a bug there, remove this dead code and reorganize a bit to avoid some code duplication. No functional change intended. Reviewed by: kib, jhb MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D45490 (cherry picked from commit 177624f2f425901bb241789d639a16bded2247ae) --- sys/kern/kern_intr.c | 64 ++++++++++++++++------------------------------------ 1 file changed, 19 insertions(+), 45 deletions(-) diff --git a/sys/kern/kern_intr.c b/sys/kern/kern_intr.c index 912504f8b1d0..6869d9112ea9 100644 --- a/sys/kern/kern_intr.c +++ b/sys/kern/kern_intr.c @@ -851,9 +851,6 @@ intr_event_remove_handler(void *cookie) struct intr_event *ie; struct intr_handler *ih; struct intr_handler **prevptr; -#ifdef notyet - int dead; -#endif if (handler == NULL) return (EINVAL); @@ -874,53 +871,30 @@ intr_event_remove_handler(void *cookie) "interrupt event \"%s\"", handler->ih_name, ie->ie_name); } - /* - * If there is no ithread, then directly remove the handler. Note that - * intr_event_handle() iterates ie_handlers in a lock-less fashion, so - * care needs to be taken to keep ie_handlers consistent and to free - * the removed handler only when ie_handlers is quiescent. - */ if (ie->ie_thread == NULL) { + /* + * If there is no ithread, then directly remove the handler. + * Note that intr_event_handle() iterates ie_handlers in a + * lock-less fashion, so care needs to be taken to keep + * ie_handlers consistent and to free the removed handler only + * when ie_handlers is quiescent. + */ CK_SLIST_REMOVE_PREVPTR(prevptr, ih, ih_next); intr_event_barrier(ie); - intr_event_update(ie); - mtx_unlock(&ie->ie_lock); - free(handler, M_ITHREAD); - return (0); + } else { + /* + * Let the interrupt thread do the job. The interrupt source is + * disabled when the interrupt thread is running, so it does not + * have to worry about interaction with intr_event_handle(). + */ + KASSERT((handler->ih_flags & IH_DEAD) == 0, + ("duplicate handle remove")); + handler->ih_flags |= IH_DEAD; + intr_event_schedule_thread(ie, NULL); + while (handler->ih_flags & IH_DEAD) + msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); } - - /* - * Let the interrupt thread do the job. - * The interrupt source is disabled when the interrupt thread is - * running, so it does not have to worry about interaction with - * intr_event_handle(). - */ - KASSERT((handler->ih_flags & IH_DEAD) == 0, - ("duplicate handle remove")); - handler->ih_flags |= IH_DEAD; - intr_event_schedule_thread(ie, NULL); - while (handler->ih_flags & IH_DEAD) - msleep(handler, &ie->ie_lock, 0, "iev_rmh", 0); intr_event_update(ie); - -#ifdef notyet - /* - * XXX: This could be bad in the case of ppbus(8). Also, I think - * this could lead to races of stale data when servicing an - * interrupt. - */ - dead = 1; - CK_SLIST_FOREACH(ih, &ie->ie_handlers, ih_next) { - if (ih->ih_handler != NULL) { - dead = 0; - break; - } - } - if (dead) { - ithread_destroy(ie->ie_thread); - ie->ie_thread = NULL; - } -#endif mtx_unlock(&ie->ie_lock); free(handler, M_ITHREAD); return (0);
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