[PATCH 01/12] mm: khugepaged: remove outdated comments and check for shmem

From: Baolin Wang

Date: Fri Sep 18 2026 - 00:00:00 EST


After commit eb92d97f7e6a ("Revert 'tmpfs: don't enable large folios if
not supported'"), all shmem mounts can support large folios unconditionally,
so drop the outdated comments and the check for shmem in collapse_file().

Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
---
mm/khugepaged.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index a3a9e4d93b46..21d75f5b4b4d 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2192,12 +2192,9 @@ static enum scan_result collapse_file(struct mm_struct *mm, unsigned long addr,
bool is_shmem = shmem_file(file);

/*
- * MADV_COLLAPSE ignores shmem huge config, so do not check shmem
- *
- * TODO: once shmem always calls mapping_set_large_folios() on its
- * mapping, the shmem check can be removed.
+ * MADV_COLLAPSE ignores shmem huge config, so do not check shmem.
*/
- VM_WARN_ON_ONCE(!is_shmem && !mapping_pmd_folio_support(mapping));
+ VM_WARN_ON_ONCE(!mapping_pmd_folio_support(mapping));
VM_WARN_ON_ONCE(start & (HPAGE_PMD_NR - 1));

result = alloc_charge_folio(&new_folio, mm, cc, HPAGE_PMD_ORDER);
--
2.47.3