diff -drupN a/include/net/net_namespace.h b/include/net/net_namespace.h
--- a/include/net/net_namespace.h	2018-08-06 17:23:04.000000000 +0300
+++ b/include/net/net_namespace.h	2022-06-12 05:28:14.000000000 +0300
@@ -41,7 +41,11 @@ struct sock;
 struct netns_ipvs;
 
 
+#ifdef CONFIG_BASE_SMALL
+#define NETDEV_HASHBITS    2
+#else
 #define NETDEV_HASHBITS    8
+#endif
 #define NETDEV_HASHENTRIES (1 << NETDEV_HASHBITS)
 
 struct net {
@@ -359,12 +363,18 @@ static inline void rt_genid_bump_ipv4(st
 	atomic_inc(&net->ipv4.rt_genid);
 }
 
+#if IS_ENABLED(CONFIG_IPV6)
 extern void (*__fib6_flush_trees)(struct net *net);
 static inline void rt_genid_bump_ipv6(struct net *net)
 {
 	if (__fib6_flush_trees)
 		__fib6_flush_trees(net);
 }
+#else
+static inline void rt_genid_bump_ipv6(struct net *net)
+{
+}
+#endif
 
 #if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN)
 static inline struct netns_ieee802154_lowpan *