On Mon, Jul 07, 2008 at 10:39:19AM -0600, Matthew Wilcox wrote: ... > > If the Local-APICs are able to redirect interrupts, then multiple CPUs > > can process the interrupts. > > That's not the only way it can work. If you have an APIC per root bus, > you can target that with the write. The APIC could then map the > interrupt request to the appropriate CPU. In this scenario, programming > affinity would be twiddling some bits in the APIC and not need to write > to the device's MSI register at all. Ok...but that still means it's got only one target (either one CPU or a group of CPUs). > What I've implemented for x86-64 can target any mask of CPUs that are > in the same interrupt domain. My machine only has one interrupt domain, > so I can target the MSI to any subset of the CPUs. They all move > together, so you can't target a different subset of CPUs for different > MSIs on the same device. *nod* - that's what I meant. thanks, grant -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
