Messages in this thread | | | Date | Fri, 04 Apr 2008 13:38:19 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 5 of 6] hotplug-memory: add section_ops |
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Christoph Lameter wrote: > Note that you could use 4k page size chunks for the memmap if its > virtualized (CONFIG_SPARSEMEM_VMEMMAP). Instead of a single PMD > pointing to a 2MB block you would have the PMD point to a block of > ptes that would in turn point to the discontiguous series of 4k pages. > > The memory is virtually contiguous so all the logic stays the same. What > would be needed is some enhancements to the way the memmap is populated.
In Xen I think that would be accommodated by the existing pseudo-physical to machine mapping. We don't support PSE anyway, so all the pages would be individual 4k pages; the fact that they're machine-discontigious is hidden because of the pseudo-phys to machine mapping when ptes are constructed.
J
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