From: Paolo Abeni
Date: Wed, 21 Jun 2017 11:45:31 +0200
> for connected socket, the incoming_cpu field in the sock struct
> is not going to change frequently, but we are setting it
> unconditionally for each packet.
>
> Since sk_incoming_cpu and sk_flags share the same cacheline,
> and the latte
for connected socket, the incoming_cpu field in the sock struct
is not going to change frequently, but we are setting it
unconditionally for each packet.
Since sk_incoming_cpu and sk_flags share the same cacheline,
and the latter is access by udp_recvmsg(), this cause a cache
miss for each packet
