diff --git a/sys/compat/linuxkpi/common/src/linux_shrinker.c b/sys/compat/linuxkpi/common/src/linux_shrinker.c
--- a/sys/compat/linuxkpi/common/src/linux_shrinker.c
+++ b/sys/compat/linuxkpi/common/src/linux_shrinker.c
@@ -92,7 +92,7 @@
 }
 
 static void
-linuxkpi_vm_lowmem(void *arg __unused)
+linuxkpi_vm_lowmem(void *arg __unused, int _2 __unused)
 {
 	struct shrinker *s;
 
diff --git a/sys/dev/drm2/ttm/ttm_page_alloc.c b/sys/dev/drm2/ttm/ttm_page_alloc.c
--- a/sys/dev/drm2/ttm/ttm_page_alloc.c
+++ b/sys/dev/drm2/ttm/ttm_page_alloc.c
@@ -441,7 +441,7 @@
 /**
  * Callback for mm to request pool to reduce number of page held.
  */
-static int ttm_pool_mm_shrink(void *arg)
+static int ttm_pool_mm_shrink(void *arg, int _1 __unused)
 {
 	static unsigned int start_pool = 0;
 	unsigned i;
diff --git a/sys/geom/eli/g_eli.c b/sys/geom/eli/g_eli.c
--- a/sys/geom/eli/g_eli.c
+++ b/sys/geom/eli/g_eli.c
@@ -194,7 +194,7 @@
 }
 
 static void
-zero_intake_passcache(void *dummy)
+zero_intake_passcache(void *dummy __unused)
 {
 	zero_boot_passcache();
 	zero_geli_intake_keys();
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -1475,7 +1475,7 @@
 }
 
 static void
-exec_args_kva_lowmem(void *arg __unused)
+exec_args_kva_lowmem(void *arg __unused, int _1 __unused)
 {
 	SLIST_HEAD(, exec_args_kva) head;
 	struct exec_args_kva *argkva;
diff --git a/sys/netinet/ip_reass.c b/sys/netinet/ip_reass.c
--- a/sys/netinet/ip_reass.c
+++ b/sys/netinet/ip_reass.c
@@ -670,6 +670,11 @@
 	VNET_LIST_RUNLOCK();
 }
 
+static void
+ipreass_drain_lowmem(void *_1 __unused, int _2 __unused)
+{
+	ipreass_drain();
+}
 
 /*
  * Initialize IP reassembly structures.
@@ -711,10 +716,10 @@
 	maxfrags = IP_MAXFRAGS;
 	EVENTHANDLER_REGISTER(nmbclusters_change, ipreass_zone_change,
 	    NULL, EVENTHANDLER_PRI_ANY);
-	EVENTHANDLER_REGISTER(vm_lowmem, ipreass_drain, NULL,
+	EVENTHANDLER_REGISTER(vm_lowmem, ipreass_drain_lowmem, NULL,
+	    LOWMEM_PRI_DEFAULT);
+	EVENTHANDLER_REGISTER(mbuf_lowmem, ipreass_drain_lowmem, NULL,
 	    LOWMEM_PRI_DEFAULT);
-	EVENTHANDLER_REGISTER(mbuf_lowmem, ipreass_drain, NULL,
-		LOWMEM_PRI_DEFAULT);
 }
 
 /*
diff --git a/sys/netinet/sctp_pcb.c b/sys/netinet/sctp_pcb.c
--- a/sys/netinet/sctp_pcb.c
+++ b/sys/netinet/sctp_pcb.c
@@ -6825,7 +6825,7 @@
 }
 
 static void
-sctp_drain(void)
+sctp_drain(void *_1 __unused, int _2 __unused)
 {
 	struct epoch_tracker et;
 
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -1384,7 +1384,7 @@
 }
 
 static void
-tcp_drain(void)
+tcp_drain(void *_1 __unused, int _2 __unused)
 {
 	struct epoch_tracker et;
 	VNET_ITERATOR_DECL(vnet_iter);
diff --git a/sys/netinet6/frag6.c b/sys/netinet6/frag6.c
--- a/sys/netinet6/frag6.c
+++ b/sys/netinet6/frag6.c
@@ -1078,7 +1078,7 @@
 }
 
 void
-frag6_drain(void)
+frag6_drain(void *_1 __unused, int _2 __unused)
 {
 	VNET_ITERATOR_DECL(vnet_iter);
 
diff --git a/sys/netinet6/ip6_var.h b/sys/netinet6/ip6_var.h
--- a/sys/netinet6/ip6_var.h
+++ b/sys/netinet6/ip6_var.h
@@ -414,7 +414,7 @@
 void	frag6_init(void);
 void	frag6_destroy(void);
 int	frag6_input(struct mbuf **, int *, int);
-void	frag6_drain(void);
+void	frag6_drain(void *, int);
 
 void	rip6_init(void);
 int	rip6_ctloutput(struct socket *, struct sockopt *);
diff --git a/sys/ufs/ufs/ufs_dirhash.c b/sys/ufs/ufs/ufs_dirhash.c
--- a/sys/ufs/ufs/ufs_dirhash.c
+++ b/sys/ufs/ufs/ufs_dirhash.c
@@ -98,7 +98,7 @@
 	   doff_t offset);
 static doff_t ufsdirhash_getprev(struct direct *dp, doff_t offset);
 static int ufsdirhash_recycle(int wanted);
-static void ufsdirhash_lowmem(void);
+static void ufsdirhash_lowmem(void*, int);
 static void ufsdirhash_free_locked(struct inode *ip);
 
 static uma_zone_t	ufsdirhash_zone;
@@ -1247,7 +1247,7 @@
  * Callback that frees some dirhashes when the system is low on virtual memory.
  */
 static void
-ufsdirhash_lowmem(void)
+ufsdirhash_lowmem(void *_1 __unused, int _2 __unused)
 {
 	struct dirhash *dh, *dh_temp;
 	int memfreed, memwanted;