Re: [PATCH v3] mm/gup: stop leaking pinned pages in low memory conditions

[John Hubbard <jhubbard@xxxxxxxxxx>]

On 10/20/24 4:26 PM, Alistair Popple wrote:
> John Hubbard <jhubbard@xxxxxxxxxx> writes:
> [...]
> > @@ -2437,8 +2440,10 @@ static long check_and_migrate_movable_pages(unsigned long nr_pages,
> >   	long i, ret;
> >   
> >   	folios = kmalloc_array(nr_pages, sizeof(*folios), GFP_KERNEL);
> > -	if (!folios)
> > +	if (!folios) {
> > +		unpin_user_pages(pages, nr_pages);
>
> ie. Doesn't this unpinning need to happen in
> check_and_migrate_movable_folios()?

It already does.

check_and_migrate_movable_folios() calls
migrate_longterm_unpinnable_folios(), which unpins if errors occur.


thanks,
--
John Hubbard