On Fri, Feb 15, 2019 at 01:08:10AM +0300, Kirill A. Shutemov wrote:
> On Thu, Feb 14, 2019 at 01:17:57PM -0800, Matthew Wilcox wrote:
> > On Thu, Feb 14, 2019 at 04:30:04PM +0300, Kirill A. Shutemov wrote:
> > > - migrate_page_move_mapping() has to be converted too.
> >
> > I think that's as simple as:
> >
> > +++ b/mm/migrate.c
> > @@ -465,7 +465,7 @@ int migrate_page_move_mapping(struct address_space
> > *mapping,
> >
> > for (i = 1; i < HPAGE_PMD_NR; i++) {
> > xas_next(&xas);
> > - xas_store(&xas, newpage + i);
> > + xas_store(&xas, newpage);
> > }
> > }
> >
> >
> > or do you see something else I missed?
>
> Looks right to me.
>
> BTW, maybe some add syntax sugar from XArray side?
>
> Replace the loop and xas_store() before it with:
>
> xas_fill(&xas, newpage, 1UL << compound_order(newpage));
>
> or something similar?
If we were keeping this code longterm, then yes, something like that
would be great. I'm hoping this code is a mere stepping stone towards
using multi-slot entries for the page cache.
