From: Hangbin Liu <[email protected]>
Date: Mon, 6 Nov 2017 09:01:57 +0800
> After commit 07f4c90062f8 ("tcp/dccp: try to not exhaust ip_local_port_range
> in connect()"), we will try to use even ports for connect(). Then if an
> application (seen clearly with iperf) opens multiple streams to the same
> destination IP and port, each stream will be given an even source port.
>
> So the bonding driver's simple xmit_hash_policy based on layer3+4 addressing
> will always hash all these streams to the same interface. And the total
> throughput will limited to a single slave.
>
> Change the tcp code will impact the whole tcp behavior, only for bonding
> usage. Paolo Abeni suggested fix this by changing the bonding code only,
> which should be more reasonable, and less impact.
>
> Fix this by discarding the lowest hash bit because it contains little entropy.
> After the fix we can re-balance between slaves.
>
> Signed-off-by: Paolo Abeni <[email protected]>
> Signed-off-by: Hangbin Liu <[email protected]>
Applied and queued up for -stable, thank you.
