From e8648a1fdb54da1f683784b36a17aa65ea56e931 Mon Sep 17 00:00:00 2001 From: Eric Dumazet <eric.dumazet@gmail.com> Date: Fri, 23 Jul 2010 12:59:36 +0200 Subject: netfilter: add xt_cpu match In some situations a CPU match permits a better spreading of connections, or select targets only for a given cpu. With Remote Packet Steering or multiqueue NIC and appropriate IRQ affinities, we can distribute trafic on available cpus, per session. (all RX packets for a given flow is handled by a given cpu) Some legacy applications being not SMP friendly, one way to scale a server is to run multiple copies of them. Instead of randomly choosing an instance, we can use the cpu number as a key so that softirq handler for a whole instance is running on a single cpu, maximizing cache effects in TCP/UDP stacks. Using NAT for example, a four ways machine might run four copies of server application, using a separate listening port for each instance, but still presenting an unique external port : iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 0 \ -j REDIRECT --to-port 8080 iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 1 \ -j REDIRECT --to-port 8081 iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 2 \ -j REDIRECT --to-port 8082 iptables -t nat -A PREROUTING -p tcp --dport 80 -m cpu --cpu 3 \ -j REDIRECT --to-port 8083 Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net> --- net/netfilter/Kconfig | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/netfilter/Kconfig') diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 551b58419df..43288259f4a 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -663,6 +663,15 @@ config NETFILTER_XT_MATCH_CONNTRACK To compile it as a module, choose M here. If unsure, say N. +config NETFILTER_XT_MATCH_CPU + tristate '"cpu" match support' + depends on NETFILTER_ADVANCED + help + CPU matching allows you to match packets based on the CPU + currently handling the packet. + + To compile it as a module, choose M here. If unsure, say N. + config NETFILTER_XT_MATCH_DCCP tristate '"dccp" protocol match support' depends on NETFILTER_ADVANCED -- cgit v1.2.3-18-g5258