From: Eric W. Biederman [mailto:ebiederm@xxxxxxxxxxxx]
Sent: Friday, February 16, 2007 12:44 AM
To: Len Brown
Cc: Andi Kleen; Protasevich, Natalie; lkml - Kernel Mailing List;
linux-acpi@xxxxxxxxxxxxxxx
Subject: Re: [PATCH] i386: irq: Kill IRQ compression
Len Brown <lenb@xxxxxxxxxx> 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