Re: [PATCH ipsec-next] xfrm: use complete IPv6 addresses for hash

From: Steffen Klassert
Date: Tue Oct 16 2018 - 04:33:27 EST


On Fri, Oct 12, 2018 at 02:24:44PM +0200, Michal Kubecek wrote:
> In some environments it is common that many hosts share the same lower half
> of their IPv6 addresses (in particular ::1). As __xfrm6_addr_hash() and
> __xfrm6_daddr_saddr_hash() calculate the hash only from the lower halves,
> as much as 1/3 of the hosts ends up in one hashtable chain which harms the
> performance.
>
> Use complete IPv6 addresses when calculating the hashes. Rather than just
> adding two more words to the xor, use jhash2() for consistency with
> __xfrm6_pref_hash() and __xfrm6_dpref_spref_hash().
>
> Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>

Applied to ipsec-next, thanks a lot!