[Bridge] Packet loss / performance

Dan Grigsby dan at unpossible.com
Mon Jan 17 21:47:37 PST 2005


Thanks for the response.  My reply follows:

> I assume this is 64-bit/66Mhz PCI.

Actually, it's a PCI-X @ 133Mhz.  

> Did you try affiniting both eth's to same CPU.

Yep, I tried with both on a single CPU, but the problem is that the eth
interfaces generate interrupts, so you need to spread the load between the
two.  Of course, NAPI helps.

> Are you always forwarding from/to same MAC address.

Yes, same MAC.

> Then figure out where they are being dropped 
> (in board, e1000 driver ring, or bridge).

I would love to know how to better determine this.  It's a little opaque to
me at the moment.  Where can I determine this?  I've been using
/proc/net/dev to see the packet numbers, but don't know how to determine
where the packets are dropped.  If you could shed light here that would be

> oprofile output might help to identify CPU hot spots.

I'll check it out.  Never used oprofile before.

Stephen Hemminger	<shemminger at osdl.org>

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