A post called John Carmack on Coding a Linux IP Stack & Winmodem on Slashdot is posted anonymously, but professes to be from John Carmack while honeymooning in Hawaii (hence his missing /. prefs) with a clarification of his thoughts on the PowerPlay announcement (story), specifically refuting the subsequent report that he plans on rewriting the Linux TCP/IP stack (story). Thanks Lawrence Ryan. Again, the post is anonymous, and I have not been able to confirm that it is by him, but it so smacks of authenticity that I'm willing to risk assuming it is. Here's a portion of the post:

No way do I intend to rewrite the linux TCP/IP stack.

I had mentioned to Yahn that it would be an interesting experiment to yank all the networking code (TCP/IP + PPP + serial driver) into user space so some cross-boundary optimization experiments can be made. I doubt there is any apreciable latency in the TCP/IP stack, but there might be some scheduling losses somewhere through PPP and the serial driver. Even if a send packet call goes syncronously all the way to the serial ring buffer, giving no real potential for latency reduction, there are still lots of possible experiments with making decisions based on normally hidden data.

Just like the GLX driver work is Good For Me as a graphics programmer, going through all the guts of the networking stack would be Good For Me as a netowrking programmer. I may pursue this, and I may collect some interesting data, but I seriously doubt it would be any contribution to the standard network stacks.

I had a long talk with a couple people from Valve about the PowerPlay initiative, but they couldn't give me enough specific technical details for me to endorse it. I'm all for improvements in networking infrastructure, but at this point, there isn't anything actually there, just an intention to improve gaming. They need to tell me SPECIFICALLY what I am supposed to be endorsing. At some point, bits have to go into packets and routers need to make decisions on them. Changes at that level is what I want to hear about, not strategic company relationships.

The entire post goes further into "networking things that could be real improvements."