From: Jesper Dangaard Brouer <bro...@redhat.com> Date: Mon, 09 Jan 2017 16:03:59 +0100
> This patchset is optimizing the ICMP-reply code path, for ICMP packets > that gets rate limited. A remote party can easily trigger this code > path by sending packets to port number with no listening service. > > Generally the patchset moves the sysctl_icmp_msgs_per_sec ratelimit > checking to earlier in the code path and removes an allocation. > > > Use-case: The specific case I experienced this being a bottleneck is, > sending UDP packets to a port with no listener, which obviously result > in kernel replying with ICMP Destination Unreachable (type:3), Port > Unreachable (code:3), which cause the bottleneck. > > After Eric and Paolo optimized the UDP socket code, the kernels PPS > processing capabilities is lower for no-listen ports, than normal UDP > sockets. This is bad for capacity planning when restarting a service. > > UDP no-listen benchmark 8xCPUs using pktgen_sample04_many_flows.sh: > Baseline: 6.6 Mpps > Patch: 14.7 Mpps > Driver mlx5 at 50Gbit/s. Series applied, thanks Jesper!
