Re: [3/5] 2.6.21-rc4: known regressions (v2)

Bjorn Helgaas
2007-04-02T16:39:23Z

On Monday 02 April 2007 09:38, Bjorn Helgaas wrote:
> The main reason we wait until pci_enable_device() to allocate an
> IRQ number is that ia64 currently only has about 180 device vectors,
> and there are machines with more PCI slots than that.

Sigh, that didn't make much sense, did it? At the time, ia64 didn't
support sharing IRQ vectors, and we preallocated four vectors for
every slot, including empty ones. Allocate-on-demand dramatically
increased the number of devices we could support because most cards
use only one IRQ.