Merge branch 'icmp-reply-optimize'

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Jesper Dangaard Brouer says:

====================
net: optimize ICMP-reply code path

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.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

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This commit is contained in:

David S. Miller 2017-01-09 15:49:13 -05:00

parent aaa9c1071d 7ba91ecb16

commit 9f2f27a9a5

2 changed files with 123 additions and 70 deletions

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125

net/ipv4/icmp.c

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68

net/ipv6/icmp.c

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