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Date: Sat, 1 Aug 2026 12:20:40 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: Hugh Dickins <hughd@google.com>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>, Jason Gunthorpe
 <jgg@ziepe.ca>, John Hubbard <jhubbard@nvidia.com>, Peter Xu
 <peterx@redhat.com>, Kiryl Shutsemau <kas@kernel.org>, Ackerley Tng
 <ackerleytng@google.com>, Frank van der Linden <fvdl@google.com>,
 linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org
Subject: Re: [PATCH] mm/gup: fix always draining LRU caches in
 collect_longterm_unpinnable_folios()
Message-Id: <20260801122040.7230a8eb0dc846ce357fba67@linux-foundation.org>
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References: <20260731-check_and_migrate_movable_folios-v1-1-e0002d7b791e@kernel.org>
	<f616e9fc-339d-4430-43ea-0ec8810c5f3b@google.com>
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On Sat, 1 Aug 2026 11:49:39 -0700 (PDT) Hugh Dickins <hughd@google.com> wrote:

> > Found by code inspection. If someone has a testcase that can easily
> > trigger this and result in migration problems, please test! But this
> > change seems to be "obvious the right thing to do".
> 
> Sorry, I don't (as perhaps is too obvious). And I'm a wee bit afraid
> that some of the problems which those changes happened to succeed in
> fixing, might now reappear once the drains are finely targeted.
> 
> Am I arguing for a delay before advancing to stable?  Perhaps, but
> I think not: it's probably best to get that working as intended,
> then deal with any fallout if it arises: just be on guard.

This patch is in mm-new, so it's still some months away from -stable
eligibility.