Re: [Hampshire] APIC, interrupts and wired NIC

Peter Salisbury <peterthevicar@???> wrote:
> I'm installing a Debian distro on a Fujitsu
> LifeBook which has a built in 10/100 NIC using
> the e100 module. All seems well except that I
> can't get more than about 50k throughput. When I
> investigated, the 'overruns' count in ifconfig
> was steadily mounting which indicates the
> machine wasn't responding quickly enough to
> incoming packets on the LAN. With the CPU at
> around 3% this seemed odd, so I looked at the
> IRQ's and found that eth0 was sharing
> /proc/irq/9 with ACPI. I rebooted with acpi=off
> and was able to get the normal 7-800k
> throughput.

I've also seen performance problems with e100
devices when they've been sharing interrupts.

Is there a BIOS option to move one or other device
onto a different IRQ? You may find that they're
physically wired to the same line, in which case
you won't be able to separate them.

You might like to try a kernel with Message-
Signalled Interrupts enabled - the IRQ will be
sent over the PCI bus in that case. I think the
e100 supports that.

Nick.

--
Nick Chalk ................. once a Radio Designer
Confidence is failing to understand the problem.