[netdrivers] Re: sundance.c : forcing mac address does not work

[Donald Becker]

On Thu, 6 Feb 2003, Philippe De Muyter wrote:

> Donald Becker wrote :
> > On Thu, 6 Feb 2003, Philippe De Muyter wrote:
> > > I now come back to my original goal.  I use the 4 channels of that board
> > > as a bonding channel, and now (with the fixed MAC address) it works,
> > > but the performances are disappointing.  For ftp or nfs transfers I can reach
> > > only 14 Mb/s between two idle Pentium III 1266MHz with 1Gb mem.
> > 
> > Presumably it works at full speed with one interface, correct?
> > 
> > I can guess two reasons:
> >   The bonding driver does a bad job of load balancing.
...
> >   The kernel is running short of memory, and it is made more likely and
> >      has more of an impact with the four port board used in bonding mode.
..
> > Could you add the following code?
> > It is a counter on how many allocate attempts failed.  The easy, sleazy
> > was to implement this is to mis-use the (usually pointless)
> > 'rx_compressed' field in the statistics.
> > The count will be reported in the "Compressed" field of /proc/net/dev.
..
> but I get only 0 in the 'compressed' field ( bond0 is eth2 + eth3 + eth4 + eth5 ) :

OK, either the counter code is somehow broken, (putting a printk instead
of the counter increment would check this), or there is some other
problem.

> Should I increase RX_RING_SIZE to 64 or more ?

Yes, that is the next step.  Doing this only wastes memory if it is not
needed.

The second source of the problem may be that only one interface is
sending interrupts.  You can check that the count in /proc/interrupts is
approximately the sum of all packets sent and received.
This is a common problem with four port cards, but you are channel
bonding all interfaces you should never see dropped packets, just a
throughput benefit from the reduced interrupts.

-- 
Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Scyld Beowulf cluster system
Annapolis MD 21403			410-990-9993