[fabbione/kronosnet] c24b22: [send/recv] use sendmmsg to reduce latency

Branch: refs/heads/master Home: https://github.com/fabbione/kronosnet Commit: c24b22f5f51d70523a447c418055bea58eb3e265 https://github.com/fabbione/kronosnet/commit/c24b22f5f51d70523a447c418055be… Author: Fabio M. Di Nitto <fdinitto(a)redhat.com> Date: 2015-11-16 (Mon, 16 Nov 2015) Changed paths: M libknet/handle.c M libknet/internals.h M libknet/threads_send_recv.c Log Message: ----------- [send/recv] use sendmmsg to reduce latency On my test systems this change reduces the latency from 0.7ms to 0.25ms when sending 65000 bytes packet and using internal re-assembly code. Internally use N buffers to split the incoming data and reduce by N frags the amount of memcpy between kernel and userland. Signed-off-by: Fabio M. Di Nitto <fdinitto(a)redhat.com>