Zhang, prior to Xen c/s 20072 there was a restriction to the number of physical IRQs Xen could handle which was tied to the number of bits that fit in a page. This restriction is needed so that the shared page IRQ-needs-EOI-notification mechanism can work with a single page. Your patch, however, changed things so that MAX_GSI_IRQS now is the number of bits in a page, while MAX_NR_IRQS is twice that value. From looking over the uses of the former I would think that this constant can be eliminated altogether, setting MAX_NR_IRQS to the correct value again and using it instead of the eliminated constant wherever needed. The effect of this will be that systems with very many GSIs (how likely is it that we''ll ever see a box with thousands of GSIs?) would simply not get much room left for IRQs to be used for MSI/MSI-X. Alternatively MAX_NR_IRQS should be returned back to its original value, and MAX_GSI_IRQS be set to e.g. half of that value. Such a restriction seems rather arbitrary to me however, hence a better alternative would then perhaps be to allow a command line override just like for nr_irqs. Thoughts? Jan _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel