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author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-07-23 12:59:36 +0200 |
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committer | Patrick McHardy <kaber@trash.net> | 2010-07-23 12:59:36 +0200 |
commit | e8648a1fdb54da1f683784b36a17aa65ea56e931 (patch) | |
tree | 66fd69f1987e4aba0025429b581d394e6db28af0 /include/linux/netfilter/xt_cpu.h | |
parent | IPVS: make FTP work with full NAT support (diff) | |
download | linux-dev-e8648a1fdb54da1f683784b36a17aa65ea56e931.tar.xz linux-dev-e8648a1fdb54da1f683784b36a17aa65ea56e931.zip |
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>
Diffstat (limited to 'include/linux/netfilter/xt_cpu.h')
-rw-r--r-- | include/linux/netfilter/xt_cpu.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/netfilter/xt_cpu.h b/include/linux/netfilter/xt_cpu.h new file mode 100644 index 000000000000..93c7f11d8f42 --- /dev/null +++ b/include/linux/netfilter/xt_cpu.h @@ -0,0 +1,11 @@ +#ifndef _XT_CPU_H +#define _XT_CPU_H + +#include <linux/types.h> + +struct xt_cpu_info { + __u32 cpu; + __u32 invert; +}; + +#endif /*_XT_CPU_H*/ |