diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
index 25c77753b2..5cb5fcc181 100644
--- a/module/zfs/dnode.c
+++ b/module/zfs/dnode.c
@@ -179,7 +179,7 @@ dnode_init(void)
 {
 	ASSERT(dnode_cache == NULL);
 	dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t),
-	    0, dnode_cons, dnode_dest, NULL, NULL, NULL, KMC_KMEM);
+	    0, dnode_cons, dnode_dest, NULL, NULL, NULL, 0);
 	kmem_cache_set_move(dnode_cache, dnode_move);
 }
 
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 97f25494cd..26c4989794 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -129,11 +129,11 @@ zio_init(void)
 	vmem_t *data_alloc_arena = NULL;
 
 	zio_cache = kmem_cache_create("zio_cache", sizeof (zio_t), 0,
-	    zio_cons, zio_dest, NULL, NULL, NULL, KMC_KMEM);
+	    zio_cons, zio_dest, NULL, NULL, NULL, 0);
 	zio_link_cache = kmem_cache_create("zio_link_cache",
-	    sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, KMC_KMEM);
+	    sizeof (zio_link_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
 	zio_vdev_cache = kmem_cache_create("zio_vdev_cache", sizeof (vdev_io_t),
-	    PAGESIZE, NULL, NULL, NULL, NULL, NULL, KMC_VMEM);
+	    PAGESIZE, NULL, NULL, NULL, NULL, NULL, 0);
 
 	/*
 	 * For small buffers, we want a cache for each multiple of
@@ -171,17 +171,6 @@ zio_init(void)
 			char name[36];
 			int flags = zio_bulk_flags;
 
-			/*
-			 * The smallest buffers (512b) are heavily used and
-			 * experience a lot of churn.  The slabs allocated
-			 * for them are also relatively small (32K).  Thus
-			 * in over to avoid expensive calls to vmalloc() we
-			 * make an exception to the usual slab allocation
-			 * policy and force these buffers to be kmem backed.
-			 */
-			if (size == (1 << SPA_MINBLOCKSHIFT))
-				flags |= KMC_KMEM;
-
 			(void) sprintf(name, "zio_buf_%lu", (ulong_t)size);
 			zio_buf_cache[c] = kmem_cache_create(name, size,
 			    align, NULL, NULL, NULL, NULL, NULL, flags);