[CRIU] Setting soft-dirty bit...

[Divjyot sethi]

Hi Pavel,
Doing echo 4>/proc/pid/clear_refs will do so for all PTEs, right? Here's
what I am doing:

I do get_user_pages() from driver to pin a user page;
I write to this user page from inside the driver (so as part of an ioctl)

It seems to me that this does not mark the page soft dirty since the write
to the page did not happen in user-mode? Also, can I explicitly call
pte_mksoft_dirty
for the pte of interest? Any pointers on this would really help.

Thanks,
Divjyot

On Wed, Sep 23, 2015 at 4:47 AM, Pavel Emelyanov <xemul at parallels.com>
wrote:

> On 09/23/2015 06:27 AM, Divjyot sethi wrote:
> > Hello,
> > I had a question about setting the soft-dirty bit. Can you please let me
> know if there
> > is a kernel API for setting this.
>
> No, it's purely in-kernel thing.
>
> > Basically, from a driver, I am pinning a page in the precess being
> pre-copied, writing some
> > info to it (from driver) and then unpinning the page. My question is
> that will this
> > automatically set the soft-dirty bit for the page? If not, is there an
> API call for doing so?
>
> It should do so once you reset the soft dirty with 'echo 4 >
> /proc/pid/clear_refs'.
>
> -- Pavel
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openvz.org/pipermail/criu/attachments/20150924/a2d92517/attachment.html>