routines
routines is the number of thread pairs to run that consume from the tun and UDP queues. Currently, this defaults to
1 which means we have 1 tun queue reader and 1 UDP queue reader. Setting this above 1 will set IFF_MULTI_QUEUE
on the tun device and SO_REUSEPORT on the UDP socket to allow multiple queues. This option is only supported on Linux.
The maximum recommended setting is half of the available CPU cores. It's recommended to set this to a lower value still, to avoid resource starvation.