Re: [PATCH 1/2] mm: introduce put_user_page*(), placeholder versions

[John Hubbard]

On 2/8/19 2:32 AM, Mike Rapoport wrote:
> On Thu, Feb 07, 2019 at 11:56:48PM -0800, john.hubbard@xxxxxxxxx wrote:
> > From: John Hubbard <jhubbard@xxxxxxxxxx>
[...]
> > +/**
> > + * put_user_page() - release a gup-pinned page
> > + * @page:            pointer to page to be released
> > + *
> > + * Pages that were pinned via get_user_pages*() must be released via
> > + * either put_user_page(), or one of the put_user_pages*() routines
> > + * below. This is so that eventually, pages that are pinned via
> > + * get_user_pages*() can be separately tracked and uniquely handled. In
> > + * particular, interactions with RDMA and filesystems need special
> > + * handling.
> > + *
> > + * put_user_page() and put_page() are not interchangeable, despite this early
> > + * implementation that makes them look the same. put_user_page() calls must
>
> I just hope we'll remember to update when the real implementation will be
> merged ;-)
>
> Other than that, feel free to add
>
> Reviewed-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>	# docs

Thanks for the review!

Yes, the follow-on patch that turns this into a real implementation is
posted [1], and its documentation is updated accordingly.

(I've already changed "@Returns" to "@Return" locally in that patch, btw.)

[1] https://lore.kernel.org/r/20190204052135.25784-5-jhubbard@xxxxxxxxxx

thanks,
--
John Hubbard
NVIDIA