Messages in this thread | | | Subject | Re: User switchable HW mappings & cie | From | Benjamin Herrenschmidt <> | Date | Tue, 10 Oct 2006 07:06:23 +1000 |
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> Anyway, so right now you can use "vm_insert_page()" and it will increment > the page count and add things to the rmap lists, which is what current > users want. But if you don't have a normal page, you should be able to > basically avoid that part entirely, and just use > > set_pte_at(mm, addr, pte, make-up-a-pte-here); > > and you're done (of course, you need to use all the appropriate magic to > set up the pte, ie you'd normally have something like > > pte = get_locked_pte(mm, addr, &ptl); > .. > pte_unmap_unlock(pte, ptl); > > around it). Note that "vm_insert_page()" is _not_ for VM_PFNMAP mappings, > exactly because it does actually increment page counts. It's for a > "normal" mapping that just wants to insert a reference-counted page.
Yes, that's why we want a vm_insert_pfn() as I really don't want to see PTE manipulations proliferate in drivers :) Nick is coming up with an implementation faster than I can think about the code anyway ;)
Cheers, Ben.
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