[dns-operations] Configurable TC=1?

[Florian Weimer]

* Robert Edmonds:

> Not to beat a long gone horse, but if you need to make a large number of
> requests, using blocking I/O and a thread-per-connection model for a
> connectionless protocol is a really bad idea.  Why didn't you use a
> single UDP socket to send queries and process responses as they came in?

Assuming we are talking about the BSD sockets API: It makes it much
easier for the kernel to deliver the response to the CPU core that
actually handles the datagram in user space, straight from the NIC.