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.
Robert Love
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This archive was generated by hypermail 2b29 : Tue Jan 15 2002 - 21:00:39 EST