On Sun, Nov 8, 2020 at 5:35 PM Darrick J. Wong <[email protected]> wrote: > > On Sun, Nov 08, 2020 at 05:15:55PM -0800, Amy Parker wrote: > > I've been writing a patch to migrate the defined DAX_ZERO_PAGE > > to XA_ZERO_ENTRY for representing holes in files. > > Why? IIRC XA_ZERO_ENTRY ("no mapping in the address space") isn't the > same as DAX_ZERO_PAGE ("the zero page is mapped into the address space > because we took a read fault on a sparse file hole"). > > --D
Matthew recommended that we use a single entry here instead of adding extra unnecessary definitions: > Right now, fs/dax.c uses a bit -- DAX_ZERO_PAGE -- > to represent a hole in the file. It could equally well use a single entry, > and we already have one defined, XA_ZERO_ENTRY. I think a patch to > convert it over would be a great idea. In practice, it works perfectly fine - ran a qemu instance with a 20 GiB NVDIMM, set up a standard namespace and ran XFS with DAX enabled on it, and then passed over it with xfstests. Nothing changed versus the current effect. _______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
