Messages in this thread | | | Date | Sat, 16 Aug 2008 15:17:35 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCH] pci: change msi-x vector to 32bit |
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On Sat, Aug 16, 2008 at 1:45 PM, James Bottomley <James.Bottomley@hansenpartnership.com> wrote: >> > What I still don't quite get is the benefit of large IRQ spaces ... >> > particularly if you encode things the system doesn't really need to know >> > in them. >> >> then set nr_irqs = nr_cpu_ids * NR_VECTORS)) >> and count down for msi/msi-x? > > No, what I mean is that msis can trip directly to CPUs, so this is an > affinity thing (that MSI is directly bound to that CPU now), so in the > matrixed way we display this in show_interrupts() with the CPU along the > top and the IRQ down the side, it doesn't make sense to me to encode IRQ > affinity in the irq number again. So it makes more sense to assign the > vectors based on both the irq number and the CPU affinity so that if the > PCI MSI for qla is assigned to CPU4 you can reassign it to CPU5 and so > on.
msi-x entry index, cpu_vector, irq number...
you want to different cpus have same vector?
YH
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