Re: Can't hit dax pmd fault on nvdimm in raw mode
On Wed, Apr 04, 2018 at 07:48:23AM -0700, Dan Williams wrote:
On Wed, Apr 4, 2018 at 7:37 AM, Xiong Zhou <xzhou(a)redhat.com>
wrote:
> Hi,
>
> It works fine in memory mode. Both tested on latest Linus tree with xfs.
>
> Referring https://nvdimm.wiki.kernel.org/2mib_fs_dax
>
> Did I miss anything?
No, this behavior is by design. See commit ee82c9ed41e8 "dax: disable
pmd mappings". The short summary is that struct page is needed to
support get_user_pages() on dax pmd mappings, and raw mappings do not
provide struct page.
Thanks very much Dan!