Re: Linux router performance (3c59x) (fwd)

On Mon, 17 Mar 2003, Ben Greear wrote:

Ralph Doncaster wrote:

[...]

quoted

Currently the box in question is running a 67% system load with ~40kpps.
Here's the switch port stats that the 2 3c905cx cards are plugged into:

  5 minute input rate 36143000 bits/sec, 8914 packets/sec
  5 minute output rate 54338000 bits/sec, 10722 packets/sec
-
  5 minute input rate 50585000 bits/sec, 12445 packets/sec
  5 minute output rate 34326000 bits/sec, 9596 packets/sec

When using larger packets, NAPI doesn't have much effect.

So I should just give up on Linux and go with FreeBSD?
http://info.iet.unipi.it/~luigi/polling/

Have you tried routing with simple routing tables to see if that
speeds anything up?

No, but I did read through a bunch of the route-cache code and even with
the dynamic hashtable size introduced in recent 2.4 revs, it looks very
ineficient for core routing.  I'd expect a speedup with a small routing
table, but then it would be useless as a core router in my network.

Could also try an e100 or Tulip NIC.  Those usually work pretty
good...  Or, could use an e1000 GigE NIC...

If I can get confirmation that under similar conditions the e1000 performs
significantly better, then I'll go that route.

It's also possible that you are just reaching the limit of your
system.

The NAPI docs imply 144kpps is easily attainable on lesser hardware than
mine.  Also I can't see bandwidth being the issue as I'm moving
<25Mbytes/sec over the PCI bus.  I should be able to do more than double
that before I have to worry about PCI saturation.

-Ralph