Re: [PATCH 2/2] Docs/mm: fix THP policy counts in transhuge

[Lorenzo Stoakes (ARM)]

On Wed, Aug 12, 2026 at 04:03:13PM +0800, Song Hu wrote:
> transhuge.rst claims seven policies for transparent_hugepage_shmem= and
> four for transparent_hugepage_tmpfs=.  Both boot parameters are parsed by
> shmem_parse_huge(), which accepts six: always, within_size, advise, never,
> deny and force.  The "four" applies only to the per-mount huge= option
> (shmem_param_enums_huge).  Fix both counts to six.
>
> Signed-off-by: Song Hu <husong@xxxxxxxxxx>
> ---
>  Documentation/admin-guide/mm/transhuge.rst | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index b187d618452f..72e944f49da5 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -389,14 +389,14 @@ is not defined within a valid ``thp_anon``, its policy will default to
>  Similarly to ``transparent_hugepage``, you can control the hugepage
>  allocation policy for the internal shmem mount by using the kernel parameter
>  ``transparent_hugepage_shmem=<policy>``, where ``<policy>`` is one of the
> -seven valid policies for shmem (``always``, ``within_size``, ``advise``,
> +six valid policies for shmem (``always``, ``within_size``, ``advise``,
>  ``never``, ``deny``, and ``force``).

I'm not sure we really want to advertise 'special' testing modes like this,
sorry. These are not modes anybody should be using in practice especially at
kernel boot. We should probably stop people doing that...!

>
>  Similarly to ``transparent_hugepage_shmem``, you can control the default
>  hugepage allocation policy for the tmpfs mount by using the kernel parameter
>  ``transparent_hugepage_tmpfs=<policy>``, where ``<policy>`` is one of the
> -four valid policies for tmpfs (``always``, ``within_size``, ``advise``,
> -``never``). The tmpfs mount default policy is ``never``.
> +six valid policies for tmpfs (``always``, ``within_size``, ``advise``,
> +``never``, ``deny``, and ``force``). The tmpfs mount default policy is ``never``.
>

Similarly here.

>  Additionally, Kconfig options are available to set the default hugepage
>  policies for shmem (``CONFIG_TRANSPARENT_HUGEPAGE_SHMEM_HUGE_*``) and tmpfs
> --
> 2.43.0
>

--
Cheers, Lorenzo