alt Hacker NewsI was pretty sure I had seen a mailing list post from Theo about it, but I can't find it now. The only relevant thread I can find is this one [1], which pretty much just says "we don't do it for userland"; but does say it is available inside the kernel, and I have seen some mentions in recent release notes for OpenBSD of binding PF things by toeplitz hash, which indicates the right progression for that ... but it's still hard to get max performance from a simple network daemon without binding the userland threads to same core that the kernel processes the flow with. Once your daemon starts doing substantial work, binding cpus isn't as important, but if it's something like an authoritative DNS server or HAProxy with plain sockets, the performance benefit from eliminating cross-core communication can be tremendous.