Re: [PATCH v4 09/23] mm/gup: introduce pin_user_pages*() and FOLL_PIN

[John Hubbard]

On 11/13/19 10:59 AM, Ira Weiny wrote:
> On Tue, Nov 12, 2019 at 08:26:56PM -0800, John Hubbard wrote:
> > Introduce pin_user_pages*() variations of get_user_pages*() calls,
> > and also pin_longterm_pages*() variations.
> >
> > These variants all set FOLL_PIN, which is also introduced, and
> > thoroughly documented.
> >
> > The pin_longterm*() variants also set FOLL_LONGTERM, in addition
> > to FOLL_PIN:
> >
> >      pin_user_pages()
> >      pin_user_pages_remote()
> >      pin_user_pages_fast()
> >
> >      pin_longterm_pages()
> >      pin_longterm_pages_remote()
> >      pin_longterm_pages_fast()
>
> At some point in this conversation I thought we were going to put in "unpin_*"
> versions of these.
>
> Is that still in the plans?

Why yes it is! :)  Daniel Vetter and Jan Kara both already weighed in [1],
in favor of "unpin_user_page*()", rather than "put_user_page*()".

I'll change those names.

[1] https://lore.kernel.org/r/20191113101210.GD6367@xxxxxxxxxxxxxx


thanks,
--
John Hubbard
NVIDIA