Messages in this thread | | | Date | Thu, 29 Jul 2010 14:55:53 -0500 (CDT) | From | Christoph Lameter <> | Subject | Re: [PATCH] Tight check of pfn_valid on sparsemem - v4 |
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On Thu, 29 Jul 2010, Russell King - ARM Linux wrote:
> And no, setting the sparse section size to 512kB doesn't work - memory is > offset by 256MB already, so you need a sparsemem section array of 1024 > entries just to cover that - with the full 256MB populated, that's 512 > unused entries followed by 512 used entries. That too is going to waste > memory like nobodies business.
SPARSEMEM EXTREME does not handle that?
Some ARMs seem to have MMUs. If so then use SPARSEMEM_VMEMMAP. You can map 4k pages for the mmap through a page table. Redirect unused 4k blocks to the NULL page.
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