[ovs-discuss] Memory Mapped I/O in Netlink

[Takayuki Usui]

Hi All,

Is anyone making a similar effort? Why don't we work together and
share the status?

I have been looking at memory mapped netlink introduced in Linux 3.10
and trying to understand its advantages and disadvantages examining
stability, performance, programmability, etc.

Since I'm focusing on the OVS kernel module and the netlink communication
right now, I'm not using the OVS user-space utilities but another simple
library to handle the netlink protocols. Even though it's still work in
progress, all the materials are available at github,

A patch for the OVS kernel module to use memory mapped netlink,
https://github.com/takayuki/openvswitch/tree/nl_mmap

And, a simple library to handle OVS netlink protocols,

A Minimalistic Approach to Open vSwitch Datapath
https://github.com/takayuki/libdpif


By the way, I was quickly skimming the archive of the list, when
I found another effort to use memory mapped netlink with OVS,

[ovs-discuss] Any plan to support memory mapped netlink?
http://openvswitch.org/pipermail/discuss/2013-July/010759.html

The patch attached to the message contains only updates in user-space,
lib/netlink-protocol.h and lib/netlink-socket.c.
But, I think some updates will be needed in kernel-space to take fully
advantage of memory mapped I/O in netlink, in particular, in communication
from kernel to user space. What do you think?


Takayuki Usui
Midokura