Messages in this thread | | | Date | Tue, 12 Aug 2003 08:22:55 -0700 | From | long <> | Subject | Re: Updated MSI Patches |
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> > > I hope there may be a way to determine the number of vectors supported > > > by CPU during the run-time. I look at the file ../include/asm-i386/mach- > > > default/irq_vectors.h, the maximum of vectors (256) is already well > > > commented. > > > > Yeah, but that's in reference to APIC interrupt sources, right? Does > > that correspond to these "vectors" too? If so, why not just use the > > existing NR_IRQS value instead of creating your own? > > There isn't a 1:1 relationship between NR_IRQS and NR_VECTORS we really > shouldn't mix them together. NR_IRQS can be much higher than 256 whilst > on i386 we're fixed to 256 vectors due to that being the Interrupt > Descriptor Table capacity. It is still possible to service more interrupt > lines than 256 on SMP however by making IDTs per 'interrupt servicing > node'
> Ah, so for processors other than i386, NR_VECTORS can be bigger?
> I think a nice description is still needed for this value for just this > reason :)
Agree. Will put some comments describing this value.
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