[Click] Changing NIC parameters for improved click performance

[Roman Chertov]

Latency Buster wrote:
> Right now, I am getting huge number of drops at the NIC rx buffer.. at
> 500bytes at 300Mbps.. The rx ring is at 4096 and I am using PollDevice
> (..., BURST 64,..). 

Are these PCI-E cards?

> 
> 1. Is  there a way to increase the rx buffer on the NIC? (intel
> 82546EB) [somewhere is e1000_defines.h?? or better via ethtool?]

'ethtool -G rx N tx N'  I believe that 4096 is the max ring size though. 
  You might want to try to use 80 sized buffers.  There are emails on 
the list that indicate that higher packet rate performance was achieved 
with 64 packet sized buffers.

> 2. I would like to balance the click threads on cpu 2 and cpu3 (as
> seen in /proc/cpuinfo). I changed the StaticThreadSched (fd0 2, td0 2,
> fd1 3 td3). But when I use ./click-install -t 2 --cpu=2 <config> I get
> a warning which says that '3' is out of range or something similar.
> 3. I have two dual port cards but I need only two links. Is it better
> to have input and outgoing links on separate cards?

The thread index is 0 based.  So I would do the following:
(fd0 0, td0 0, fd1 1, td1 1)
The X parameter for --cpu should be largest thread index in your config + 1.

Roman

> 
> Thanks..
>