Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts

From: David Dillow
Date: Sat May 23 2009 - 13:03:45 EST


On Sat, 2009-05-23 at 18:53 +0200, Michael Riepe wrote:
>
> David Dillow wrote:
> > On Sat, 2009-05-23 at 18:12 +0200, Michael Riepe wrote:
> >
> >>If I use two connections (iperf -P2) and nail iperf to both threads of a
> >>single core with taskset (the program is multi-threaded, just in case
> >>you wonder), I get this:
> >>
> >>CPU 0+2: 0.0-60.0 sec 4.65 GBytes 665 Mbits/sec
> >>CPU 1+3: 0.0-60.0 sec 6.43 GBytes 920 Mbits/sec
> >>
> >>That's quite a difference, isn't it?
> >>
> >>Now I wonder what CPU 0 is doing...
> >
> >
> > Where does /proc/interrupts say the irqs are going?
>
> Oh well...

> 27: 48463995 0 0 0 PCI-MSI-edge eth0

What does it look like if you move the iperf around the CPUs while using
pci=nomsi?

I'm looking to make sure I didn't cause a terrible regression in the
cost of IRQ handling...

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