diff mbox series

[net-next,2/4] ipv6: Use a 31-bit multipath hash

Message ID 20180109144028.30133-3-idosch@mellanox.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series ipv6: Add support for non-equal-cost multipath | expand

Commit Message

Ido Schimmel Jan. 9, 2018, 2:40 p.m. UTC 
The hash thresholds assigned to IPv6 nexthops are in the range of
[-1, 2^31 - 1], where a negative value is assigned to nexthops that
should not be considered during multipath selection.

Therefore, in a similar fashion to IPv4, we need to use the upper
31-bits of the multipath hash for multipath selection.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
---
 net/ipv6/route.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

David Ahern Jan. 10, 2018, 3:43 a.m. UTC | #1 
On 1/9/18 7:40 AM, Ido Schimmel wrote:
> The hash thresholds assigned to IPv6 nexthops are in the range of
> [-1, 2^31 - 1], where a negative value is assigned to nexthops that
> should not be considered during multipath selection.
> 
> Therefore, in a similar fashion to IPv4, we need to use the upper
> 31-bits of the multipath hash for multipath selection.
> 
> Signed-off-by: Ido Schimmel <idosch@mellanox.com>
> ---
>  net/ipv6/route.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 

Acked-by: David Ahern <dsahern@gmail.com>
diff mbox series

Patch

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index ced2c9bed10b..09e8e10b101d 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1833,10 +1833,10 @@  u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb)
 
 	if (skb) {
 		ip6_multipath_l3_keys(skb, &hash_keys);
-		return flow_hash_from_keys(&hash_keys);
+		return flow_hash_from_keys(&hash_keys) >> 1;
 	}
 
-	return get_hash_from_flowi6(fl6);
+	return get_hash_from_flowi6(fl6) >> 1;
 }
 
 void ip6_route_input(struct sk_buff *skb)