On Mon, Feb 06, 2017 at 09:30:22AM -0800, Dan Williams wrote: > On Mon, Feb 6, 2017 at 9:27 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > > On Mon, Feb 06, 2017 at 08:24:48AM -0800, Dan Williams wrote: > >> > Also can be use this opportunity > >> > to fold ->huge_fault into ->fault? BTW, for tmpfs we already use ->fault for both small and huge pages. If ->fault returned THP, core mm look if it's possible to map the page as huge in this particular VMA (due to size/alignment). If yes mm maps the page with PMD, if not fallback to PTE. I think it would be nice to do the same for DAX: filesystem provides core mm with largest page this part of file can be mapped with (base aligned address + lenght for DAX) and core mm sort out the rest. > >> Hmm, yes, just need a scheme to not attempt huge_faults on pte-only handlers. > > > > Do we need anything more than checking vma->vm_flags for VM_HUGETLB? > > s/VM_HUGETLB/VM_HUGEPAGE/ > > ...but yes as long as we specify that a VM_HUGEPAGE handler must > minimally handle pud and pmd. VM_HUGEPAGE is result of MADV_HUGEPAGE. It's not required to have THP in the VMA. -- Kirill A. Shutemov -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
