From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Bohrer Subject: [net-next 0/3] Improve UDP multicast receive latency Date: Tue, 1 Oct 2013 14:33:42 -0500 Message-ID: <1380656025-8847-1-git-send-email-sbohrer@rgmadvisors.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: Eric Dumazet , tomk@rgmadvisors.com, netdev , Shawn Bohrer To: David Miller Return-path: Received: from na3sys009aog126.obsmtp.com ([74.125.149.155]:41496 "EHLO na3sys009aog126.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750881Ab3JATeY (ORCPT ); Tue, 1 Oct 2013 15:34:24 -0400 Received: by mail-oa0-f43.google.com with SMTP id f4so5335302oah.30 for ; Tue, 01 Oct 2013 12:34:23 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: The removal of the routing cache in 3.6 had impacted the latency of our UDP multicast workload. This patch series brings down the latency to what we were seeing with 3.4. Patch 1 "udp: Only allow busy read/poll on connected sockets" is mostly done for correctness and because it allows unifying the unicast and multicast paths when a socket is found in early demux. It can also improve latency for a connected multicast socket if busy read/poll is used. Patches 2&3 remove the fib lookups and restore latency for our workload to the pre 3.6 levels. Benchmark results from a netperf UDP_RR test: 3.11 kernel 90596.44 transactions/s 3.11 + series 91792.70 transactions/s Benchmark results from a fio 1 byte UDP multicast pingpong test (Multicast one way unicast response): 3.11 kernel 12.647us RTT 3.11 + series 12.233us RTT Shawn Bohrer (3): udp: Only allow busy read/poll on connected sockets udp: Add udp early demux net: ipv4 only populate IP_PKTINFO when needed include/net/ip.h | 2 +- include/net/sock.h | 2 +- include/net/udp.h | 1 + net/ipv4/af_inet.c | 1 + net/ipv4/ip_sockglue.c | 5 +- net/ipv4/raw.c | 2 +- net/ipv4/udp.c | 160 +++++++++++++++++++++++++++++++++++++++++------ net/ipv6/udp.c | 5 +- 8 files changed, 150 insertions(+), 28 deletions(-) -- 1.7.7.6 -- --------------------------------------------------------------- This email, along with any attachments, is confidential. If you believe you received this message in error, please contact the sender immediately and delete all copies of the message. Thank you.