Re: [PATCH] mm/hugetlb: mm/memory_hotplug: use a folio in scan_movable_pages()

[Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>]

On 5/28/24 3:47 PM, Matthew Wilcox wrote:
> On Tue, May 28, 2024 at 03:03:21PM -0700, Sidhartha Kumar wrote:
> > @@ -1761,9 +1762,9 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
> >   		 * cases false positives and negatives are possible.  Calling
> >   		 * code must deal with these scenarios.
> >   		 */
> > -		if (HPageMigratable(head))
> > +		if (folio_test_hugetlb_migratable(folio))
> >   			goto found;
> > -		skip = compound_nr(head) - (pfn - page_to_pfn(head));
> > +		skip = folio_nr_pages(folio) - folio_page_idx(folio, page);
> >   		pfn += skip - 1;
>
> Isn't this an unnecessarily complicated way of writing:
>
> 		pfn |= folio_nr_pages(folio) - 1;
> ?

Because folio_nr_pages() is a power of 2, I agree this is simpler. I'll make 
this change in a v2.

Thanks,
Sid