Re: [PATCH v1 14/39] mm/rmap: introduce folio_add_anon_rmap_[pte|ptes|pmd]()

[David Hildenbrand]

> > -	if (flags & RMAP_EXCLUSIVE)
> > -		SetPageAnonExclusive(page);
> > -	/* While PTE-mapping a THP we have a PMD and a PTE mapping. */
> > -	VM_WARN_ON_FOLIO((atomic_read(&page->_mapcount) > 0 ||
> > -			  (folio_test_large(folio) && folio_entire_mapcount(folio) > 1)) &&
> > -			 PageAnonExclusive(page), folio);
> > +
> > +	if (flags & RMAP_EXCLUSIVE) {
> > +		switch (mode) {
> > +		case RMAP_MODE_PTE:
> > +			for (i = 0; i < nr_pages; i++)
> > +				SetPageAnonExclusive(page + i);
> > +			break;
> > +		case RMAP_MODE_PMD:
> > +			SetPageAnonExclusive(page);
>
> Just to check; I suppose only setting this on the head is ok, because it's an
> exclusive mapping and therefore by definition it can only be mapped by pmd?

Yes. And when PTE-remapping, we will push the flag to all tail pages. No 
change in behavior :)

--
Cheers,

David / dhildenb