Re: [PATCH 1/3] Separate IRQ-stacks from 4K-stacks option

[Timothy Miller]

Arjan van de Ven wrote:
> On Fri, Sep 10, 2004 at 05:28:52PM +0200, Andrea Arcangeli wrote:
>
> > On Fri, Sep 10, 2004 at 05:15:38PM +0200, Arjan van de Ven wrote:
> >
> > > because it gives people a reason to do sloppy coding.
> >
> > it's not about bad drivers, it's about the number of nested interrupts
> > not being limited by software right now.
> >
> >
> > > What we should consider regardless is disable the nesting of irqs for
> > > performance reasons but that's an independent matter
> >
> > disabling nesting completely sounds a bit too aggressive, but limiting
> > the nesting is probably a good idea.
>
>
> disabling is actually not a bad idea; hard irq handlers run for a very short
> time, but when they nest you effectively have like a semi context switch in
> the middle of the work so performance suffers...


The rules about how long a hard irq would be allowed to run would have 
to be draconian.

... not that that would be a problem.


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