Re: [2.4.17/18pre] VM and swap - it's really unusable

yodaiken
2002-01-12T19:40:50Z

On Sat, Jan 12, 2002 at 02:26:27PM -0500, Robert Love wrote:
> On Sat, 2002-01-12 at 13:54, Alan Cox wrote:
> > Another example is in the network drivers. The 8390 core for one example
> > carefully disables an IRQ on the card so that it can avoid spinlocking on
> > uniprocessor boxes.
> >
> > So with pre-empt this happens
> >
> > driver magic
> > disable_irq(dev->irq)
> > PRE-EMPT:
> > [large periods of time running other code]
> > PRE-EMPT:
> > We get back and we've missed 300 packets, the serial port sharing
> > the IRQ has dropped our internet connection completely.
>
> We don't preempt while IRQ are disabled.

You read the mask map? and somehow figure out which masked irqs correspond to
active devices?

>
> Robert Love
>
> -
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--
---------------------------------------------------------
Victor Yodaiken
Finite State Machine Labs: The RTLinux Company.
www.fsmlabs.com www.rtlinux.com