Re: [PATCH 04/11] mm: add PG_dropbehind folio flag
From: Kirill A. Shutemov
Date: Fri Dec 20 2024 - 10:13:01 EST
On Fri, Dec 20, 2024 at 04:03:44PM +0100, David Hildenbrand wrote:
> On 20.12.24 12:08, Kirill A. Shutemov wrote:
> > On Fri, Dec 13, 2024 at 08:55:18AM -0700, Jens Axboe wrote:
> > > Add a folio flag that file IO can use to indicate that the cached IO
> > > being done should be dropped from the page cache upon completion.
> > >
> > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> >
> > Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> >
> > + David, Vlastimil.
> >
> > I think we should consider converting existing folio_set_reclaim() /
> > SetPageReclaim() users to the new flag. From a quick scan, all of them
> > would benefit from dropping the page after writeback is complete instead
> > of leaving the folio on the LRU.
>
> I wonder of there are some use cases where we write a lot of data to then
> only consume it read-only from that point on (databases? fancy AI stuff? no
> idea :) ).
Do we use PG_reclaim for such cases?
--
Kiryl Shutsemau / Kirill A. Shutemov