Shared memory of some kind will be fastest. It requires a re-architecture of the application, some of the times. Unfortunately, I can't find the Linux kernel ma

Shared memory of some kind will be fastest. It requires a re-architecture of the application, some of the times. Unfortunately, I can't find the Linux kernel mailing list response any more, but the kernel devs were not sympathetic to the use case of processes communicating over TCP on the same host.