On Sun, Jan 31, 2010 at 10:14:03PM +1100, Anton Blanchard wrote:

With dynamic irq descriptors the overhead of a large NR_IRQS is much lower
than it used to be. With more MSI-X capable adapters and drivers exploiting 
multiple vectors we may as well allow the user to increase it beyond the
current maximum of 512.

32768 seems large enough that we'd never have to bump it again (although I bet
my prediction is horribly wrong). It boot tests OK and the vmlinux footprint
increase is only around 500kB due to:

Only 1/2 MB? 

I'm running Linux on 12 year old PPC machines which have 16MB
or RAM (ok, they are still running an old kernel, but a few
patches like this and they wont't even boot). The kernels
I have are well below 1MB, code+data+bss. 

Yes it is configurable, thanks, and 64 is enough for these
machines (8259 plus an MPIC), so it's not that crucial.

What I object to is calling 1/2MB negligible.

	Gabriel