[PATCH v6 05/14] mm: remove READ_ONLY_THP_FOR_FS Kconfig option

From: Zi Yan

Date: Sun May 17 2026 - 09:57:03 EST


After removing READ_ONLY_THP_FOR_FS check in file_thp_enabled(),
khugepaged and MADV_COLLAPSE can run on FSes with PMD THP pagecache
support even without READ_ONLY_THP_FOR_FS enabled. Remove the Kconfig
first so that no one can use READ_ONLY_THP_FOR_FS as upcoming commits
remove mapping->nr_thps, which its safe guard mechanism relies on.

Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@xxxxxxxxxx>
Acked-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Nico Pache <npache@xxxxxxxxxx>
Reviewed-by: Lance Yang <lance.yang@xxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Barry Song <baohua@xxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Dev Jain <dev.jain@xxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Liam Howlett <liam@xxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Nico Pache <npache@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Shuah Khan <shuah@xxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxxxxx>
---
mm/Kconfig | 11 -----------
1 file changed, 11 deletions(-)

diff --git a/mm/Kconfig b/mm/Kconfig
index e221fa1dc54d0..27dc5b0139ba6 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -936,17 +936,6 @@ config THP_SWAP

For selection by architectures with reasonable THP sizes.

-config READ_ONLY_THP_FOR_FS
- bool "Read-only THP for filesystems (EXPERIMENTAL)"
- depends on TRANSPARENT_HUGEPAGE
-
- help
- Allow khugepaged to put read-only file-backed pages in THP.
-
- This is marked experimental because it is a new feature. Write
- support of file THPs will be developed in the next few release
- cycles.
-
config NO_PAGE_MAPCOUNT
bool "No per-page mapcount (EXPERIMENTAL)"
help
--
2.53.0