[merged mm-stable] mm-rmap-add-a-zone_device-folio-warning-in-folio_referenced.patch removed from -mm tree

[merged mm-stable] mm-rmap-add-a-zone_device-folio-warning-in-folio_referenced.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: rmap: add a ZONE_DEVICE folio warning in folio_referenced()
has been removed from the -mm tree.  Its filename was
     mm-rmap-add-a-zone_device-folio-warning-in-folio_referenced.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: mm: rmap: add a ZONE_DEVICE folio warning in folio_referenced()
Date: Fri, 6 Mar 2026 14:43:39 +0800

The folio_referenced() is used to test whether a folio was referenced
during reclaim.  Moreover, ZONE_DEVICE folios are controlled by their
device driver, have a lifetime tied to that driver, and are never placed
on the LRU list.  That means we should never try to reclaim ZONE_DEVICE
folios, so add a warning to catch this unexpected behavior in
folio_referenced() to avoid confusion, as discussed in the previous
thread[1].

[1] https://lore.kernel.org/all/16fb7985-ec0f-4b56-91e7-404c5114f899@kernel.org/
Link: https://lkml.kernel.org/r/64d6fb2a33f7101e1d4aca2c9052e0758b76d492.1772778858.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Xu <weixugc@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yuanchu Xie <yuanchu@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/rmap.c |    1 +
 1 file changed, 1 insertion(+)

--- a/mm/rmap.c~mm-rmap-add-a-zone_device-folio-warning-in-folio_referenced
+++ a/mm/rmap.c
@@ -1072,6 +1072,7 @@ int folio_referenced(struct folio *folio
 		.invalid_vma = invalid_folio_referenced_vma,
 	};
 
+	VM_WARN_ON_ONCE_FOLIO(folio_is_zone_device(folio), folio);
 	*vm_flags = 0;
 	if (!pra.mapcount)
 		return 0;
_

Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are

mm-filemap-fix-nr_pages-calculation-overflow-in-filemap_map_pages.patch
mm-vmscan-fix-dirty-folios-throttling-on-cgroup-v1-for-mglru.patch