diff --git a/sys/dev/netmap/netmap_kern.h b/sys/dev/netmap/netmap_kern.h
--- a/sys/dev/netmap/netmap_kern.h
+++ b/sys/dev/netmap/netmap_kern.h
@@ -81,6 +81,7 @@
 
 #if defined(__FreeBSD__)
 #include <sys/selinfo.h>
+#include <vm/vm.h>
 
 #define likely(x)	__builtin_expect((long)!!(x), 1L)
 #define unlikely(x)	__builtin_expect((long)!!(x), 0L)
@@ -1727,10 +1728,27 @@
 #define NM_IS_NATIVE(ifp)	(NM_NA_VALID(ifp) && NA(ifp)->nm_dtor == netmap_hw_dtor)
 
 #if defined(__FreeBSD__)
+/*
+ * On FreeBSD, the group ID of a memory pool refers to the NUMA domain rather
+ * than an IOMMU domain.
+ */
+static inline int
+nm_iommu_group_id(struct netmap_adapter *na)
+{
+	int domain;
 
-/* Assigns the device IOMMU domain to an allocator.
- * Returns -ENOMEM in case the domain is different */
-#define nm_iommu_group_id(dev) (-1)
+	/*
+	 * If the system has only one NUMA domain, don't bother distinguishing
+	 * between -1 and domain 0.  Otherwise we may end up needlessly
+	 * allocating new memory pools.
+	 */
+	if (vm_ndomains == 1)
+		return (-1);
+	domain = if_getnumadomain(na->ifp);
+	if (domain == IF_NODOM)
+		return (-1);
+	return (domain);
+}
 
 /* Callback invoked by the dma machinery after a successful dmamap_load */
 static void netmap_dmamap_cb(__unused void *arg,
diff --git a/sys/dev/netmap/netmap_mem2.c b/sys/dev/netmap/netmap_mem2.c
--- a/sys/dev/netmap/netmap_mem2.c
+++ b/sys/dev/netmap/netmap_mem2.c
@@ -37,8 +37,8 @@
 #endif /* __APPLE__ */
 
 #ifdef __FreeBSD__
-#include <sys/cdefs.h> /* prerequisite */
 #include <sys/types.h>
+#include <sys/domainset.h>
 #include <sys/malloc.h>
 #include <sys/kernel.h>		/* MALLOC_DEFINE */
 #include <sys/proc.h>
@@ -174,7 +174,7 @@
 	struct netmap_obj_pool pools[NETMAP_POOLS_NR];
 
 	nm_memid_t nm_id;	/* allocator identifier */
-	int nm_grp;	/* iommu group id */
+	int nm_grp;		/* iommu group id */
 
 	/* list of all existing allocators, sorted by nm_id */
 	struct netmap_mem_d *prev, *next;
@@ -310,7 +310,7 @@
 
 static int netmap_mem_map(struct netmap_obj_pool *, struct netmap_adapter *);
 static int netmap_mem_unmap(struct netmap_obj_pool *, struct netmap_adapter *);
-static int nm_mem_check_group(struct netmap_mem_d *, bus_dma_tag_t);
+static int nm_mem_check_group(struct netmap_mem_d *, void *);
 static void nm_mem_release_id(struct netmap_mem_d *);
 
 nm_memid_t
@@ -728,7 +728,7 @@
 }
 
 static int
-nm_mem_check_group(struct netmap_mem_d *nmd, bus_dma_tag_t dev)
+nm_mem_check_group(struct netmap_mem_d *nmd, void *dev)
 {
 	int err = 0, id;
 
@@ -1399,7 +1399,7 @@
 
 /* call with NMA_LOCK held */
 static int
-netmap_finalize_obj_allocator(struct netmap_obj_pool *p)
+netmap_finalize_obj_allocator(struct netmap_mem_d *nmd, struct netmap_obj_pool *p)
 {
 	int i; /* must be signed */
 
@@ -1440,8 +1440,16 @@
 		 * can live with standard malloc, because the hardware will not
 		 * access the pages directly.
 		 */
-		clust = contigmalloc(p->_clustsize, M_NETMAP, M_NOWAIT | M_ZERO,
-		    (size_t)0, -1UL, PAGE_SIZE, 0);
+		if (nmd->nm_grp == -1) {
+			clust = contigmalloc(p->_clustsize, M_NETMAP,
+			    M_NOWAIT | M_ZERO, (size_t)0, -1UL, PAGE_SIZE, 0);
+		} else {
+			struct domainset *ds;
+
+			ds = DOMAINSET_PREF(nmd->nm_grp);
+			clust = contigmalloc_domainset(p->_clustsize, M_NETMAP,
+			    ds, M_NOWAIT | M_ZERO, (size_t)0, -1UL, PAGE_SIZE, 0);
+		}
 		if (clust == NULL) {
 			/*
 			 * If we get here, there is a severe memory shortage,
@@ -1634,7 +1642,7 @@
 	nmd->lasterr = 0;
 	nmd->nm_totalsize = 0;
 	for (i = 0; i < NETMAP_POOLS_NR; i++) {
-		nmd->lasterr = netmap_finalize_obj_allocator(&nmd->pools[i]);
+		nmd->lasterr = netmap_finalize_obj_allocator(nmd, &nmd->pools[i]);
 		if (nmd->lasterr)
 			goto error;
 		nmd->nm_totalsize += nmd->pools[i].memtotal;