diff --git a/sys/geom/geom_event.c b/sys/geom/geom_event.c
--- a/sys/geom/geom_event.c
+++ b/sys/geom/geom_event.c
@@ -347,6 +347,7 @@
 g_post_event_ep_va(g_event_t *func, void *arg, int wuflag,
     struct g_event *ep, va_list ap)
 {
+	struct thread *td;
 	void *p;
 	u_int n;
 
@@ -366,8 +367,12 @@
 	TAILQ_INSERT_TAIL(&g_events, ep, events);
 	mtx_unlock(&g_eventlock);
 	wakeup(&g_wait_event);
-	curthread->td_pflags |= TDP_GEOM;
-	ast_sched(curthread, TDA_GEOM);
+
+	td = curthread;
+	if ((td->td_pflags & TDP_KTHREAD) == 0) {
+		td->td_pflags |= TDP_GEOM;
+		ast_sched(td, TDA_GEOM);
+	}
 }
 
 void
diff --git a/sys/kern/kern_thr.c b/sys/kern/kern_thr.c
--- a/sys/kern/kern_thr.c
+++ b/sys/kern/kern_thr.c
@@ -346,6 +346,17 @@
 
 	p = td->td_proc;
 
+	/*
+	 * Clear kernel ASTs in advance of selecting the last exiting
+	 * thread and collecting schedulers locks.  It is fine to
+	 * clear that ASTs there even if we are not going to exit
+	 * after all.  On the other hand, having them pending could
+	 * trigger that subsystems in the context that is not prepared
+	 * to handle top kernel actions, even in execution of an
+	 * unrelated thread.
+	 */
+	ast_kclear(td);
+
 	/*
 	 * If all of the threads in a process call this routine to
 	 * exit (e.g. all threads call pthread_exit()), exactly one