IP6_VTI_HASH_SIZE_SHIFT   51 net/ipv6/ip6_vti.c #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT)
IP6_VTI_HASH_SIZE_SHIFT   57 net/ipv6/ip6_vti.c 	return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT);