On Thu, Aug 31, 2023 at 04:21:53PM +0100, Ryan Roberts wrote:
> On 25/08/2023 14:59, Matthew Wilcox (Oracle) wrote:
> > @@ -2478,7 +2478,11 @@ void free_unref_folios(struct folio_batch *folios)
> > for (i = 0, j = 0; i < folios->nr; i++) {
> > struct folio *folio = folios->folios[i];
> > unsigned long pfn = folio_pfn(folio);
> > - if (!free_unref_page_prepare(&folio->page, pfn, 0))
> > + unsigned int order = folio_order(folio);
>
> Do you need to do anything special for hugetlb folios? I see that
> destroy_large_folio() has:
>
> if (folio_test_hugetlb(folio)) {
> free_huge_folio(folio);
> return;
> }
Right; hugetlb folios get freed specially and never come this way.
I could put in an assertion, I suppose?
> > @@ -2486,11 +2490,13 @@ void free_unref_folios(struct folio_batch *folios)
> > * comment in free_unref_page.
> > */
> > migratetype = get_pcppage_migratetype(&folio->page);
> > - if (unlikely(is_migrate_isolate(migratetype))) {
> > + if (order > PAGE_ALLOC_COSTLY_ORDER ||
>
> Should this be `if (!pcp_allowed_order(order) ||` ? That helper includes the THP
> pageblock_order too.
Oh, yes, that's obviously far better than what I had here. I got the
BUG in order_to_pindex() and didn't think to look around for the
correct predicate. Thanks!
