vr(4) performance

[Joerg Sonnenberger]

On Thu, Nov 02, 2006 at 06:11:00PM -0500, Devon H. O'Dell wrote:
> So, vr(4) kind of sucks, and it seems like this is mostly due to the
> fact that we call m_defrag() on every mbuf that we send through it.
> This seems to really screw performance on outgoing packets (something
> like 33% the output efficiency of fxp(4), if I'm understanding this
> all correctly).

What hardware are you running at that it is a problem? Seriously --
copying 100Mbit/s in memory shouldn't fully busy any post-2k
non-embedded CPU. You could just allocate a static output queue and copy
into that, dropping at least the allocations of the mbuf clusters, but I
don't think it should b worth it.

And yes, if you can sustain Fast Ethernet speed with scp to localhost,
m_defrag is absolutely not the main problem.

Joerg