Re: Can't hit dax pmd fault on nvdimm in raw mode
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.
Details here:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit...