On Thu, 2016-12-08 at 13:19 -0500, David Miller wrote: > From: Eric Dumazet <eric.duma...@gmail.com> > Date: Wed, 07 Dec 2016 08:29:10 -0800 > > > From: Eric Dumazet <eduma...@google.com> > > > > RFS is not commonly used, so add a jump label to avoid some conditionals > > in fast path. > > > > Signed-off-by: Eric Dumazet <eduma...@google.com> > > Applied, but I wonder how effective this will really be in the long run.
I guess this applies to about all jump labels. As soon as the attribute is per namespace, we no longer can use them. A conditional cost really depends on the expression complexity (including cache line misses) TCP stack might benefit from jump labels, like sysctl_tcp_low_latency which is often set to 1 on hosts mostly using epoll()/poll()/select() instead of blocking read()/recvmsg()
