Re: [PATCH v5 05/14] mm: remove READ_ONLY_THP_FOR_FS Kconfig option

Nico Pache
2026-05-04T04:02:01Z

On 4/29/26 9:35 AM, Zi Yan wrote:
> 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@nvidia.com>
> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
> Acked-by: David Hildenbrand (Arm) <david@kernel.org>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> ---
> 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

Yay its gone! Thanks for working on this :)

Reviewed-by: Nico Pache <npache@redhat.com>

> - 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