IIUC this series is about devdax namespace with aligh of 1G or 2M where we can
save the vmmemap space by not allocating memory for tail struct pages?
Dan Williams <dan.j.williams@xxxxxxxxx> writes:
> > enum:
>> >
>> > enum devmap_geometry {
>> > DEVMAP_PTE,
>> > DEVMAP_PMD,
>> > DEVMAP_PUD,
>> > }
>> >
>> I suppose a converter between devmap_geometry and page_size would be needed too? And maybe
>> the whole dax/nvdimm align values change meanwhile (as a followup improvement)?
>
> I think it is ok for dax/nvdimm to continue to maintain their align
> value because it should be ok to have 4MB align if the device really
> wanted. However, when it goes to map that alignment with
> memremap_pages() it can pick a mode. For example, it's already the
> case that dax->align == 1GB is mapped with DEVMAP_PTE today, so
> they're already separate concepts that can stay separate.
devdax namespace with align of 1G implies we expect to map them with 1G
pte entries? I didn't follow when you say we map them today with
DEVMAP_PTE entries.
-aneesh
