On 14.09.2010 11:18, Fabien Thomas wrote: > Great, > > This will maybe kill the long time debate about "my loopback is slow vs linux" > To have the best of both world what about a socket option to enable/disable fusing: > can be useful when you need to see some connection "packetized". A sysctl to that effect is already in the patch. -- Andre > Fabien > > On 13 sept. 2010, at 13:33, Andre Oppermann wrote: > >> When a TCP connection via loopback back to localhost is made the whole >> send, segmentation and receive path (with larger packets though) is still >> executed. This has some considerable overhead. >> >> To short-circuit the send and receive sockets on localhost TCP connections >> I've made a proof-of-concept patch that directly places the data in the >> other side's socket buffer without doing any packetization and other protocol >> overhead (like UNIX domain sockets). The connections setup (SYN, SYN-ACK, >> ACK) and shutdown are still handled by normal TCP segments via loopback so >> that firewalling stills works. The actual payload data during the session >> won't be seen and the sequence numbers don't move other than for SYN and FIN. >> The sequence are remain valid though. Obviously tcpdump won't see any data >> transfers either if the connection has fused sockets. >> >> Preliminary testing (with WITNESS and INVARIANTS enabled) has shown stable >> operation and a rough doubling of the throughput on loopback connections. >> I've tested most socket teardown cases and it behaves fine. I'm not entirely >> sure I've got all possible path's but the way it is integrated should properly >> defuse the sockets in all situations. >> >> Testers and feedback wanted: >> >> http://people.freebsd.org/~andre/tcp_loopfuse-20100913.diff >> >> -- >> Andre >> >> _______________________________________________ >> freebsd-net_at_freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-net >> To unsubscribe, send any mail to "freebsd-net-unsubscribe_at_freebsd.org" > > >Received on Tue Sep 14 2010 - 13:41:03 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:07 UTC