Re: [PATCH v4 net-next 0/2] ipv4: Hash-based multipath routing

From: David Miller <davem@davemloft.net>
Date: Mon, 28 Sep 2015 19:33:55 -0700 (PDT)

From: Peter Nørlund <redacted>
Date: Wed, 23 Sep 2015 21:49:35 +0200

quoted

When the routing cache was removed in 3.6, the IPv4 multipath algorithm changed
from more or less being destination-based into being quasi-random per-packet
scheduling. This increases the risk of out-of-order packets and makes it
impossible to use multipath together with anycast services.

This patch series replaces the old implementation with flow-based load
balancing based on a hash over the source and destination addresses.

This isn't perfect but it's a significant step in the right direction.
So I'm going to apply this to net-next now and we can make incremental
improvements upon it.

Actually, I had to revert, this doesn't build:

[davem@localhost net-next]$ make -s -j8
Setup is 16876 bytes (padded to 16896 bytes).
System is 10011 kB
CRC 324f2811
Kernel: arch/x86/boot/bzImage is ready  (#337)
ERROR: "__ip_route_output_key_hash" [net/dccp/dccp_ipv4.ko] undefined!
scripts/Makefile.modpost:90: recipe for target '__modpost' failed
make[1]: *** [__modpost] Error 1
Makefile:1095: recipe for target 'modules' failed
make: *** [modules] Error 2