Re: [PATCH] sparse_irq aka dyn_irq v13

["H. Peter Anvin" <hpa@zytor.com>]

Yinghai Lu wrote:
>>
>> I really don't think anyone gives a hoot about the IRQ number for any
>> IRQ above the 0-15 legacy range, even including the "APIC" numbers 16+.
> 
> you want to change ioapic/pin to irq mapping too?
> so INTx and MSI will call create_irq_nr to get one irq for 16, and following first come and first serve rule.
> 

I personally don't think there is any issue with changing ioapic/pin to
IRQ mapping.  Other people may disagree.  My opinion is that IRQ numbers
16-23 are somewhat useful when you're dealing with a single IOAPIC, but
after that it's all a blur.

It would, however, be a good idea if IOAPICs had their numbers assigned
at detection time, as opposed to when the interrupt is registered, thus
making it a stable number for a single boot, at least.  The same is
probably true for MSI(-X); we could assign it a range of numbers when
the device is enumerated (as opposed to when a driver is activated), but
I don't know to what extent that is likely to cause more troubles than
it solves.

	-hpa