Re: [PATCH alt 13/25] mm/fbatch: no lru_add_drain() to collect_longterm_unpinnable_folios()

[Hugh Dickins]

On Mon, 24 Aug 2026, David Hildenbrand (Arm) wrote:
> On 8/24/26 16:55, Hugh Dickins wrote:
> > collect_longterm_unpinnable_folios() has no use for lru_add_drain() nor
> > lru_add_drain_all(), now that the per-cpu fbatch references are gone.
> > So remove the recently added lru_cache_drain_for_folio().
> > 
> > Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
> > ---
> > Alternate version for use once David Hildenbrand's two commits
> > here have been pulled from mm.git into linux.git for 7.3-rc1.
> 
> For 7.4 we expect another user of the helper in KVM guest_memfd code (the
> primary reason why we introduce the helper), so depending on when this series is
> ready it will just remove that user as well, or we'll need some coordination
> between trees.

Yes, I could supply an alternate alternate version, providing an empty
stub for lru_cache_drain_for_folio(), so Ackerley's and my series can
proceed (or not) independently. Later. But at present your patch or
patches seem to be in both mm.git and Ackerley's series (17/46),
but not yet in Linus's tree.

Hugh