Re: [PATCH RFC 06/37] mm: page_alloc: Allocate from movable pcp lists only if ALLOC_FROM_METADATA

Catalin Marinas
2023-10-17T10:26:48Z

On Mon, Oct 16, 2023 at 01:41:15PM +0100, Alexandru Elisei wrote:
> On Thu, Oct 12, 2023 at 10:25:11AM +0900, Hyesoo Yu wrote:
> > I don't think it would be effcient when the majority of movable pages
> > do not use GFP_TAGGED.
> >
> > Metadata pages have a low probability of being in the pcp list
> > because metadata pages is bypassed when freeing pages.
> >
> > The allocation performance of most movable pages is likely to decrease
> > if only the request with ALLOC_FROM_METADATA could be allocated.
>
> You're right, I hadn't considered that.
>
> >
> > How about not including metadata pages in the pcp list at all ?
>
> Sounds reasonable, I will keep it in mind for the next iteration of the
> series.

BTW, I suggest for the next iteration we drop MIGRATE_METADATA, only use
CMA and assume that the tag storage itself supports tagging. Hopefully
it makes the patches a bit simpler.

--
Catalin