On Wed, Sep 27, 2017 at 4:49 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
> Now that we always have pages for DAX we can stop setting VM_MIXEDMAP.
> This does require some small fixups for the pte insert routines that dax
> utilizes.
>
This changelog can be improved with this from the cover letter:
VM_MIXEDMAP is used by dax to direct mm paths like vm_normal_page() that
the memory page it is dealing with is not typical memory from the linear
map. The get_user_pages_fast() path, since it does not resolve the vma,
is already using {pte,pmd}_devmap() as a stand-in for VM_MIXEDMAP, so we
use that as a VM_MIXEDMAP replacement in some locations. In the cases
where there is no pte to consult we fallback to using vma_is_dax() to
detect the VM_MIXEDMAP special case.
...I'll fold this in for v2.
