Re: [PATCH v9 14/41] mm: swap: Introduce lru_add_drain_progressive()

[Sean Christopherson <seanjc@google.com>]

On Fri, Jul 31, 2026, David Hildenbrand (Arm) wrote:
> I sent a fix for the GUP code that always makes us drain right now:
> 
> https://lore.kernel.org/r/20260731-check_and_migrate_movable_folios-v1-1-e0002d7b791e@kernel.org
> 
> Would the following (agains mm-unstable + fix) work for you?
> 
> 
> I assume that you'd have to call it as
> 
> 	lru_cache_drain_for_folio(folio, 0, NULL);
> 
> But maybe there are indeed extra references that are not reflected in
> folio_expected_ref_count() that you would have to consider? I doubt it, but please check if
> there would be a problem.
> 
> There is a small problem for merging:
> 
> (1) The patch depends on the fix.
> 
> (2) mm/swap.c was moved to mm/folio.c in the mm tree.
> 
> We could write what I have below against Linus' tree and have the conflict be
> resolved when merging. Topic branches are unfortunately not yet a thing in MM
> land.

Are you expecting the aforementioned fix to land in 7.2, 7.3, or 7.4?  If it's
7.2 or 7.3, then I would strongly prefer to base v10 on linux-next (where the fix
will presumably land soonish), and target 7.4 for in-place conversion.  Then v10
can be applied against an early 7.3-rcN and we don't need to juggle branches
(assuming Andrew is ok taking the proposed patch through the KVM tree).

Irrespective of this small mm issue, it's getting a bit too late in the 7.3 cycle
to land the in-place series, and we need to address Xiaoyao's comments, i.e. v10
is going to be necessary no matter what.