Re: [PATCH RFC 15/39] mm/huge_memory: batch rmap operations in __split_huge_pmd_locked()

[David Hildenbrand]

On 05.12.23 13:22, Ryan Roberts wrote:
> On 04/12/2023 14:21, David Hildenbrand wrote:
> > Let's use folio_add_anon_rmap_ptes(), batching the rmap operations.
> >
> > While at it, use more folio operations (but only in the code branch we're
> > touching), use VM_WARN_ON_FOLIO(), and pass RMAP_COMPOUND instead of
>
> You mean RMAP_EXCLUSIVE?

Indeed.

[...]

> > -		if (!freeze)
> > -			page_ref_add(page, HPAGE_PMD_NR - 1);
> > +		if (!freeze) {
> > +			rmap_t rmap_flags = RMAP_NONE;
> > +
> > +			folio_ref_add(folio, HPAGE_PMD_NR - 1);
> > +			if (anon_exclusive)
> > +				rmap_flags = RMAP_EXCLUSIVE;
>
> nit: I'd be inclined to make this |= since you're accumulating optional falgs.
> Yes, its the only one so it still works as is...


Make sense!

--
Cheers,

David / dhildenb