[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] NR_PIRQS vs. NR_IRQS
I'm having some difficulty understanding why these two need to be distinguished: Depending on the code location, an IRQ passed in from the guest may be checked against NR_PIRQS (map_domain_pirq() as called from PHYSDEVOP_alloc_irq_vector) or NR_IRQS (PHYSDEVOP_irq_status_query, PHYSDEVOP_map_pirq), despite it having the same source. Also, tying NR_IRQS to NR_VECTORS seems bogus - even with current code I can't see why we shouldn't be able to support a higher NR_IRQS without immediately doing the more involved code changes needed to also grow NR_VECTORS. After all, NR_IRQS is directly tied to the number of IO-APIC pins we can support - in order to support a device, its cumulative pin number (being the irq) must be below NR_IRQS. But since very likely not all pins are connected to devices, NR_VECTORS is much less of a limiting factor. Thanks, Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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