Re: [PATCH v2 1/3] mm/huge_memory: don't ignore queried cachemode in vmf_insert_pfn_pud()

[Dan Williams]

David Hildenbrand wrote:
> We setup the cache mode but ... don't forward the updated pgprot to
> insert_pfn_pud().
> 
> Only a problem on x86-64 PAT when mapping PFNs using PUDs that
> require a special cachemode.

This is only a problem if the kernel mapped the pud in advance of userspace
mapping it, right?

The change looks good.

Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx>

...but I am struggling with the scenario where this causes problems in
practice, where vm_page_prot is the wrong cachemode.