Re: [PATCH] i386: irq: Kill IRQ compression

Eric W. Biederman
2007-02-16T07:45:43Z

Len Brown <lenb@kernel.org> writes:

> This code makes simple systems complex:
>
> ACPI: PCI Interrupt 0000:03:04.0[A] -> GSI 18 (level, low) -> IRQ 16
> ACPI: PCI Interrupt 0000:00:1d.0[A] -> GSI 16 (level, low) -> IRQ 17
> ACPI: PCI Interrupt 0000:00:1d.1[B] -> GSI 19 (level, low) -> IRQ 18
> ACPI: PCI Interrupt 0000:00:1d.7[D] -> GSI 23 (level, low) -> IRQ 19
>
> The same code was already removed from x86_64

By itself I don't think we are going to observe any real problems
with this patch.

However if we are going to be serious about this we need to do a
few more things.

- kill iopaic_renumber_irq.
- Increase NR_IRQS.

We will still be limited to about 208 interrupts in use at one
time, but we can allow more irq sources to be described.

This reminds me. I really need to dig up my patch that doesn't
allocate a vector for an irq until request irq time.

Eric