Re: [PATCH v6 08/14] mm/gup: do not migrate zero page

From: Pavel Tatashin
Date: Mon Jan 25 2021 - 10:48:20 EST


On Mon, Jan 25, 2021 at 9:28 AM Jason Gunthorpe <jgg@xxxxxxxx> wrote:
>
> On Wed, Jan 20, 2021 at 09:26:41AM -0500, Pavel Tatashin wrote:
>
> > I thought about this, and it would code a little cleaner. But, the
> > reason I did not is because zero_page is perfectly pinnable, it is not
> > pinnable only when it is in a movable zone (and it should not be in a
> > movable zones for other reasons as well), but that is another bug that
> > needs to be resolved, and once that bug is resolved this condition can
> > be removed from gup migration.
>
> My point is you've defined the zero page to be pinnable no matter what
> zone it is in, so is_pinnable(zero_page) == true

Sure, I will move it inside is_pinnable in the next update.

Thank you,
Pasha

>
> Jason