At some point in the past, someone wrote: >># define pfn_to_page(pfn) (vmem_map + (pfn)) >># define page_to_pfn(page) ((unsigned long) (page - vmem_map)) On Sat, Jun 21, 2003 at 07:48:08AM -0700, Martin J. Bligh wrote: > I really don't see how you *can't* do that, and have it still work. > If the mem_map is placed in node local memory, and not a size that > happens to be a complete number of pages, even if you pack it down > into a vmem_map, it's still not contiguous. So adding a pfn (physical > page frame number) to the base of vmem_map can NOT give you the correct > address. > Presumably this *is* working for you ... but I'm buggered if I know how ;-) > Maybe I just need more coffee ;-) It's a sparse array. The interstices between nodes are padded with empty virtualspace in order to cheapen the indexing operation. i.e. the nodes' local mem_map's are virtually positioned according to the range of pfns they span. If 32-bit weren't as pressed for virtualspace it could do likewise. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Mon Jun 23 13:22:17 2003
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