Merge branch 'setsockopt_incoming_cpu'

Eric Dumazet says:

====================
tcp: better smp listener behavior

As promised in last patch series, we implement a better SO_REUSEPORT
strategy, based on cpu hints if given by the application.

We also moved sk_refcnt out of the cache line containing the lookup
keys, as it was considerably slowing down smp operations because
of false sharing. This was simpler than converting listen sockets
to conventional RCU (to avoid sk_refcnt dirtying)

Could process 6.0 Mpps SYN instead of 4.2 Mpps on my test server.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>