Re: [PATCH net-next] net: sock_rps_record_flow() is for connected sockets

On Wed, 2016-12-07 at 06:29 -0800, Eric Dumazet wrote:

On Wed, 2016-12-07 at 08:57 +0100, Paolo Abeni wrote:

quoted

We have some experimental patches to implement GRO for plain UDP
connected sockets, using frag_list to preserve the individual skb len,
and deliver the packet to user space individually. With that I got
~3mpps with a single queue/user space sink - before the recent udp
improvements. I would like to present these patches on netdev soon (no
sooner than next week, anyway).

Make sure you handle properly all netfilter helpers :(

Thank you for the head-up! 
UDP-GRO will be enabled by a specific netdev feature bit, disabled by
default, should not impact by default any setup.

Keeping frag_list means you keep one sk_buff per segment, so this really
looks like a legacy UDP server (like a DNS server) wont benefit from
this anyway.

I'm sorry, I do not follow.

UDP GRO will require connected socket - very likely no DNS server. The
use-case is an application using long lived UDP sockets doing a lot of
traffic, like fix protocol feeds over UDP. 

Thank you,

Paolo