linux/include
Shawn Bohrer 421b3885bf udp: ipv4: Add udp early demux
The removal of the routing cache introduced a performance regression for
some UDP workloads since a dst lookup must be done for each packet.
This change caches the dst per socket in a similar manner to what we do
for TCP by implementing early_demux.

For UDP multicast we can only cache the dst if there is only one
receiving socket on the host.  Since caching only works when there is
one receiving socket we do the multicast socket lookup using RCU.

For UDP unicast we only demux sockets with an exact match in order to
not break forwarding setups.  Additionally since the hash chains may be
long we only check the first socket to see if it is a match and not
waste extra time searching the whole chain when we might not find an
exact match.

Benchmark results from a netperf UDP_RR test:
Before 87961.22 transactions/s
After  89789.68 transactions/s

Benchmark results from a fio 1 byte UDP multicast pingpong test
(Multicast one way unicast response):
Before 12.97us RTT
After  12.63us RTT

Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-08 16:27:33 -04:00
..
acpi Merge branch 'acpi-hotplug' 2013-08-30 14:14:25 +02:00
asm-generic include/asm-generic/vtime.h: avoid zero-length file 2013-09-30 14:31:02 -07:00
clocksource ARM: SoC cleanups for 3.12 2013-09-06 13:21:16 -07:00
crypto crypto: scatterwalk - Add support for calculating number of SG elements 2013-08-21 21:27:58 +10:00
drm Revert "drm: mark context support as a legacy subsystem" 2013-09-20 08:32:59 +10:00
dt-bindings Device tree core updates for v3.12 2013-09-10 13:53:52 -07:00
keys
kvm ARM: KVM: vgic: Bump VGIC_NR_IRQS to 256 2013-08-30 16:12:39 +03:00
linux net: Separate the close_list and the unreg_list v2 2013-10-07 15:23:14 -04:00
math-emu
media Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-09-05 14:54:29 -07:00
memory
misc
net udp: ipv4: Add udp early demux 2013-10-08 16:27:33 -04:00
pcmcia
ras
rdma Merge branches 'cxgb4', 'flowsteer', 'ipoib', 'iser', 'mlx4', 'ocrdma' and 'qib' into for-next 2013-09-03 09:01:08 -07:00
rxrpc
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2013-09-12 16:11:45 -07:00
sound sound fixes for 3.12-rc1 2013-09-12 08:52:41 -07:00
target target/iscsi: Bump versions to v4.1.0 2013-09-10 20:23:37 -07:00
trace Merge branch 'for-3.12/core' of git://git.kernel.dk/linux-block 2013-09-22 15:00:11 -07:00
uapi Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2013-10-04 13:26:38 -04:00
video fbdev changes for 3.12: 2013-09-05 09:49:32 -07:00
xen Features: 2013-09-04 17:45:39 -07:00
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