You can probably keep buffers very small with megapipe, since syscalls are batched together, so they can't impact throughput very much in case of many concurrent connections. You still get a lot of memory taken out of kernel per syscall, but spread across many connections, if I understood megapipe correctly.
Well sure you could do that. But I don't believe that reading say 50 bytes at a time is very efficient even when you factor in automatic syscall batching.
But this is all speculation. I didn't any consideration for this problem in the paper at all so I don't have the impression it was on the researchers' radar.
