Re: [PATCH net-next 3/4] ipv6: Use hash-threshold instead of modulo-N

On 1/9/18 7:40 AM, Ido Schimmel wrote:

Now that each nexthop stores its region boundary in the multipath hash
function's output space, we can use hash-threshold instead of modulo-N
in multipath selection.

This reduces the number of checks we need to perform during lookup, as
dead and linkdown nexthops are assigned a negative region boundary. In
addition, in contrast to modulo-N, only flows near region boundaries are
affected when a nexthop is added or removed.

Signed-off-by: Ido Schimmel <redacted>
---
 net/ipv6/route.c | 36 +++++++++++++-----------------------
 1 file changed, 13 insertions(+), 23 deletions(-)

Did you consider adding the net->ipv4.sysctl_fib_multipath_use_neigh
check as well? ie., if set, verify neighbor is alive before picking that hop

Acked-by: David Ahern <redacted>