From: Dan Williams <dan.j.williams@intel.com>
To: Xiong Zhou <xzhou@redhat.com>
Cc: linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: Can't hit dax pmd fault on nvdimm in raw mode
Date: Wed, 4 Apr 2018 07:48:23 -0700 [thread overview]
Message-ID: <CAPcyv4iyzpSVKmV_dC2TyUkbX0J69bqzNT_eQGM9vMXqBac1qA@mail.gmail.com> (raw)
In-Reply-To: <20180404143713.t4lsufodbe7pr2jm@XZHOUW.usersys.redhat.com>
On Wed, Apr 4, 2018 at 7:37 AM, Xiong Zhou <xzhou@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/?id=ee82c9ed41e8
_______________________________________________
Linux-nvdimm mailing list
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm
next prev parent reply other threads:[~2018-04-04 14:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-04 14:37 Can't hit dax pmd fault on nvdimm in raw mode Xiong Zhou
2018-04-04 14:48 ` Dan Williams [this message]
2018-04-05 1:03 ` Xiong Zhou
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CAPcyv4iyzpSVKmV_dC2TyUkbX0J69bqzNT_eQGM9vMXqBac1qA@mail.gmail.com \
--to=dan.j.williams@intel.com \
--cc=linux-nvdimm@lists.01.org \
--cc=xzhou@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).