Re: [PATCH v2 1/3] mm: kick writeback flusher instead of inline flush for IOCB_DONTCACHE

Christoph Hellwig
2026-04-09T14:21:42Z

On Thu, Apr 09, 2026 at 09:21:36AM +0200, Jan Kara wrote:
> > So I think you'll want a new WB_start_dontcache bit, a new
> > get_nr_dontcache_pages() helper on a new node counter, etc.
>
> But I'm not sure how you imagine this would work without restricting
> writeback to particular inodes. Maybe we could mark inodes which have
> folios with dropbehind set and make flush worker only write such inodes?

I'd only expedite writing by the number of pending dontcache folios.
It would still write the least recently dirtied inodes.