Re: [PATCH 3/4] mm/readahead: add a_ops->ra_folio_order to get a desired folio order

Jaegeuk Kim
2025-12-01T21:24:43Z

On 12/01, Matthew Wilcox wrote:
> On Mon, Dec 01, 2025 at 09:01:26PM +0000, Jaegeuk Kim wrote:
> > This patch introduces a new address operation, a_ops->ra_folio_order(), which
> > proposes a new folio order based on the adjusted order for page_cache_sync_ra.
> >
> > Hence, each filesystem can set the desired minimum order of folio allocation
> > when requesting fadvise(POSIX_FADV_WILLNEED).
>
> Again, you've said what but not why. Does the mm code not ramp up the
> folio order sufficiently quickly? What are you trying to accomplish?

That's why I posted a series of the patches to provide more details. Could you
please check the last patch in the series to show fadvise() does not increase
the folio order?