diff --git a/share/man/man9/g_event.9 b/share/man/man9/g_event.9
--- a/share/man/man9/g_event.9
+++ b/share/man/man9/g_event.9
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd January 16, 2004
+.Dd July 23, 2021
 .Dt G_EVENT 9
 .Os
 .Sh NAME
@@ -40,6 +40,10 @@
 .Fn g_waitfor_event "g_event_t *func" "void *arg" "int flag" ...
 .Ft void
 .Fn g_cancel_event "void *ref"
+.Ft "struct g_event *"
+.Fn g_alloc_event "int flag"
+.Ft void
+.Fn g_post_event_ep "g_event_t *func" "void *arg" "struct g_event *ep" ...
 .Sh DESCRIPTION
 The GEOM framework has its own event queue to inform classes about important
 events.
@@ -80,6 +84,13 @@
 It waits until the event is finished or canceled and then returns.
 .Pp
 The
+.Fn g_post_event_ep
+function posts the event with a pre-allocated
+.Va struct g_event .
+An event may be pre-allocated with
+.Fn g_alloc_event .
+.Pp
+The
 .Fn g_cancel_event
 function cancels all event(s) identified by
 .Fa ref .
@@ -123,6 +134,25 @@
 function cannot be called from an event, since doing so would result
 in a deadlock.
 .El
+.Pp
+.Fn g_alloc_event :
+.Bl -item -offset indent
+.It
+The argument
+.Fa flag
+has to be
+.Dv M_WAITOK
+or
+.Dv M_NOWAIT .
+.It
+The returned
+.Va struct g_event *
+must be freed with
+.Fn g_free
+if
+.Fn g_post_event_ep
+is not called.
+.El
 .Sh RETURN VALUES
 The
 .Fn g_post_event
diff --git a/sys/geom/geom.h b/sys/geom/geom.h
--- a/sys/geom/geom.h
+++ b/sys/geom/geom.h
@@ -260,6 +260,7 @@
 
 /* geom_event.c */
 typedef void g_event_t(void *, int flag);
+struct g_event;
 #define EV_CANCEL	1
 int g_post_event(g_event_t *func, void *arg, int flag, ...);
 int g_waitfor_event(g_event_t *func, void *arg, int flag, ...);
@@ -269,6 +270,8 @@
 int g_media_gone(struct g_provider *pp, int flag);
 void g_orphan_provider(struct g_provider *pp, int error);
 void g_waitidlelock(void);
+struct g_event *g_alloc_event(int flag);
+void g_post_event_ep(g_event_t *func, void *arg, struct g_event *ep, ...);
 
 /* geom_subr.c */
 int g_access(struct g_consumer *cp, int nread, int nwrite, int nexcl);
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
@@ -341,20 +341,22 @@
 	mtx_unlock(&g_eventlock);
 }
 
-static int
-g_post_event_x(g_event_t *func, void *arg, int flag, int wuflag, struct g_event **epp, va_list ap)
+struct g_event *
+g_alloc_event(int flag)
+{
+	KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
+	    ("Wrong flag to g_alloc_event"));
+
+	return (g_malloc(sizeof(struct g_event), flag | M_ZERO));
+}
+
+static void
+g_post_event_ep_va(g_event_t *func, void *arg, int wuflag,
+    struct g_event *ep, va_list ap)
 {
-	struct g_event *ep;
 	void *p;
 	u_int n;
 
-	g_trace(G_T_TOPOLOGY, "g_post_event_x(%p, %p, %d, %d)",
-	    func, arg, flag, wuflag);
-	KASSERT(wuflag == 0 || wuflag == EV_WAKEUP,
-	    ("Wrong wuflag in g_post_event_x(0x%x)", wuflag));
-	ep = g_malloc(sizeof *ep, flag | M_ZERO);
-	if (ep == NULL)
-		return (ENOMEM);
 	ep->flag = wuflag;
 	for (n = 0; n < G_N_EVENTREFS; n++) {
 		p = va_arg(ap, void *);
@@ -371,12 +373,38 @@
 	TAILQ_INSERT_TAIL(&g_events, ep, events);
 	mtx_unlock(&g_eventlock);
 	wakeup(&g_wait_event);
-	if (epp != NULL)
-		*epp = ep;
 	curthread->td_pflags |= TDP_GEOM;
 	thread_lock(curthread);
 	curthread->td_flags |= TDF_ASTPENDING;
 	thread_unlock(curthread);
+}
+
+void
+g_post_event_ep(g_event_t *func, void *arg, struct g_event *ep, ...)
+{
+	va_list ap;
+
+	va_start(ap, ep);
+	g_post_event_ep_va(func, arg, 0, ep, ap);
+	va_end(ap);
+}
+
+
+static int
+g_post_event_x(g_event_t *func, void *arg, int flag, int wuflag, struct g_event **epp, va_list ap)
+{
+	struct g_event *ep;
+
+	g_trace(G_T_TOPOLOGY, "g_post_event_x(%p, %p, %d, %d)",
+	    func, arg, flag, wuflag);
+	KASSERT(wuflag == 0 || wuflag == EV_WAKEUP,
+	    ("Wrong wuflag in g_post_event_x(0x%x)", wuflag));
+	ep = g_alloc_event(flag);
+	if (ep == NULL)
+		return (ENOMEM);
+	if (epp != NULL)
+		*epp = ep;
+	g_post_event_ep_va(func, arg, wuflag, ep, ap);
 	return (0);
 }