Messages in this thread | | | Date | Thu, 02 May 2002 12:31:52 -0700 | From | "Martin J. Bligh" <> | Subject | Re: Bug: Discontigmem virt_to_page() [Alpha,ARM,Mips64?] |
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> You don't need any additional common code abstraction to make virtual > address 3G+256G to point to physical address 1G as in my example above, > after that you're free to put the physical ram between 1G and 1G+256M > into the zone normal of node 1 and the stuff should keep working but > with zone-normal spread in more than one node. You just have full > control on virt_to_page, pci_map_single, __va. Actually it may be as > well cleaner to just let the arch define page_address() when > discontigmem is enabled (instead of hacking on top of __va), that's a > few liner. (the only true limit you have is on the phys ram above 4G, > that cannot definitely go into zone-normal regardless if it belongs to a > direct mapping or not because of pci32 API)
The thing that's special about ZONE_NORMAL is that it's permanently mapped into kernel virtual address space, so you *cannot* put memory in other nodes into ZONE_NORMAL without changing the mapping between physical to virtual memory to a non 1-1 mapping.
No, you don't need to call changing that mapping "CONFIG_NONLINEAR", but that's basically what the bulk of Dan's patch does, so I think we should steal it with impunity ;-)
M.
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