RE: Why no interrupt priorities?

Grover, Andrew
2004-02-27T01:39:50Z

> On Thursday 26 February 2004 13:30, Arjan van de Ven wrote:
> > hardware IRQ priorities are useless for the linux model. In
> linux, the
> > hardirq runs *very* briefly and then lets the softirq context do the
> > longer taking work. hardware irq priorities then don't matter really
> > because the hardirq's are hardly ever interrupted really,
> and when they
> > are they cause a performance *loss* due to cache trashing.
> The latency
> > added by waiting briefly is going to be really really short
> for any sane
> > hardware.

Is the assumption that hardirq handlers are superfast also the reason
why Linux calls all handlers on a shared interrupt, even if the first
handler reports it was for its device?

-- Andy