Good point. This is more of a tcp stack comparison between the kernel and userspace. Seastar has a sharded (per core) stack, which is very beneficial when the number of threads is high
You can set up one or many rings per core, but the idea I alluded to elsewhere in this comment section of spending 2 cores to do kernel busy polling and userspace busy polling for a single ring is less useful if your alternative makes good use of all cores.
