On Fri, Jun 8, 2018 at 10:00 AM, Dave Jiang <dave.jiang@xxxxxxxxx> wrote: > This patch is reworked from an earlier patch that Dan has posted: > https://patchwork.kernel.org/patch/10131727/ > > 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. > > Now that we have explicit driver pfn_t-flag opt-in/opt-out for > get_user_pages() support for DAX we can stop setting VM_MIXEDMAP. This > also means we no longer need to worry about safely manipulating vm_flags > in a future where we support dynamically changing the dax mode of a > file. > > DAX should also now be supported with madvise_behavior(), vma_merge(), > and copy_page_range(). > > This patch has been tested against ndctl unit test. It has also been > tested against xfstests commit: 625515d using fake pmem created by memmap > and no additional issues have been observed. > > Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx> Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>
