If we add ``thp_anon=32,64K:always`` to the kernel command line, we
will see the following error:

[    0.000000] huge_memory: thp_anon=32,64K:always: error parsing string, ignoring setting

This happens because the correct format isn't ``thp_anon=<size>,<size>[KMG]:<state>```,
as [KMG] must follow each number to especify its unit. So, the correct
format is ``thp_anon=<size>[KMG],<size>[KMG]:<state>```.

Therefore, adjust the documentation to reflect the correct format of the
parameter ``thp_anon=``.

Fixes: dd4d30d1cdbe ("mm: override mTHP "enabled" defaults at kernel cmdline")
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Acked-by: Barry Song <baohua@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
---
 Documentation/admin-guide/kernel-parameters.txt | 2 +-
 Documentation/admin-guide/mm/transhuge.rst      | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 1518343bbe22..1666576acc0e 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6688,7 +6688,7 @@
 			0: no polling (default)
 
 	thp_anon=	[KNL]
-			Format: <size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>
+			Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
 			state is one of "always", "madvise", "never" or "inherit".
 			Control the default behavior of the system with respect
 			to anonymous transparent hugepages.
diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
index 203ba7aaf5fc..745055c3dc09 100644
--- a/Documentation/admin-guide/mm/transhuge.rst
+++ b/Documentation/admin-guide/mm/transhuge.rst
@@ -303,7 +303,7 @@ control by passing the parameter ``transparent_hugepage=always`` or
 kernel command line.
 
 Alternatively, each supported anonymous THP size can be controlled by
-passing ``thp_anon=<size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>``,
+passing ``thp_anon=<size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>``,
 where ``<size>`` is the THP size (must be a power of 2 of PAGE_SIZE and
 supported anonymous THP)  and ``<state>`` is one of ``always``, ``madvise``,
 ``never`` or ``inherit``.
-- 
2.46.2

On Tue, Oct 29, 2024 at 8:24 AM Maíra Canal <mcanal@igalia.com> wrote:
>
> If we add ``thp_anon=32,64K:always`` to the kernel command line, we
> will see the following error:
>
> [    0.000000] huge_memory: thp_anon=32,64K:always: error parsing string, ignoring setting
>
> This happens because the correct format isn't ``thp_anon=<size>,<size>[KMG]:<state>```,
> as [KMG] must follow each number to especify its unit. So, the correct
> format is ``thp_anon=<size>[KMG],<size>[KMG]:<state>```.
>
> Therefore, adjust the documentation to reflect the correct format of the
> parameter ``thp_anon=``.
>
> Fixes: dd4d30d1cdbe ("mm: override mTHP "enabled" defaults at kernel cmdline")
> Signed-off-by: Maíra Canal <mcanal@igalia.com>
> Acked-by: Barry Song <baohua@kernel.org>
> Acked-by: David Hildenbrand <david@redhat.com>

Can we separate this and apply it to v6.12-rc? If Andrew doesn't require a new
version for the separation, can we extract it from this series and
apply it to mm?

> ---
>  Documentation/admin-guide/kernel-parameters.txt | 2 +-
>  Documentation/admin-guide/mm/transhuge.rst      | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 1518343bbe22..1666576acc0e 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -6688,7 +6688,7 @@
>                         0: no polling (default)
>
>         thp_anon=       [KNL]
> -                       Format: <size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>
> +                       Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
>                         state is one of "always", "madvise", "never" or "inherit".
>                         Control the default behavior of the system with respect
>                         to anonymous transparent hugepages.
> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
> index 203ba7aaf5fc..745055c3dc09 100644
> --- a/Documentation/admin-guide/mm/transhuge.rst
> +++ b/Documentation/admin-guide/mm/transhuge.rst
> @@ -303,7 +303,7 @@ control by passing the parameter ``transparent_hugepage=always`` or
>  kernel command line.
>
>  Alternatively, each supported anonymous THP size can be controlled by
> -passing ``thp_anon=<size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>``,
> +passing ``thp_anon=<size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>``,
>  where ``<size>`` is the THP size (must be a power of 2 of PAGE_SIZE and
>  supported anonymous THP)  and ``<state>`` is one of ``always``, ``madvise``,
>  ``never`` or ``inherit``.
> --
> 2.46.2
>

Thanks
Barry

Hi Barry,

On 28/10/24 22:03, Barry Song wrote:
> On Tue, Oct 29, 2024 at 8:24 AM Maíra Canal <mcanal@igalia.com> wrote:
>>
>> If we add ``thp_anon=32,64K:always`` to the kernel command line, we
>> will see the following error:
>>
>> [    0.000000] huge_memory: thp_anon=32,64K:always: error parsing string, ignoring setting
>>
>> This happens because the correct format isn't ``thp_anon=<size>,<size>[KMG]:<state>```,
>> as [KMG] must follow each number to especify its unit. So, the correct
>> format is ``thp_anon=<size>[KMG],<size>[KMG]:<state>```.
>>
>> Therefore, adjust the documentation to reflect the correct format of the
>> parameter ``thp_anon=``.
>>
>> Fixes: dd4d30d1cdbe ("mm: override mTHP "enabled" defaults at kernel cmdline")
>> Signed-off-by: Maíra Canal <mcanal@igalia.com>
>> Acked-by: Barry Song <baohua@kernel.org>
>> Acked-by: David Hildenbrand <david@redhat.com>
> 
> Can we separate this and apply it to v6.12-rc? If Andrew doesn't require a new
> version for the separation, can we extract it from this series and
> apply it to mm?

That's fine on my side.

Best Regards,
- Maíra

> 
>> ---
>>   Documentation/admin-guide/kernel-parameters.txt | 2 +-
>>   Documentation/admin-guide/mm/transhuge.rst      | 2 +-
>>   2 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
>> index 1518343bbe22..1666576acc0e 100644
>> --- a/Documentation/admin-guide/kernel-parameters.txt
>> +++ b/Documentation/admin-guide/kernel-parameters.txt
>> @@ -6688,7 +6688,7 @@
>>                          0: no polling (default)
>>
>>          thp_anon=       [KNL]
>> -                       Format: <size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>
>> +                       Format: <size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>
>>                          state is one of "always", "madvise", "never" or "inherit".
>>                          Control the default behavior of the system with respect
>>                          to anonymous transparent hugepages.
>> diff --git a/Documentation/admin-guide/mm/transhuge.rst b/Documentation/admin-guide/mm/transhuge.rst
>> index 203ba7aaf5fc..745055c3dc09 100644
>> --- a/Documentation/admin-guide/mm/transhuge.rst
>> +++ b/Documentation/admin-guide/mm/transhuge.rst
>> @@ -303,7 +303,7 @@ control by passing the parameter ``transparent_hugepage=always`` or
>>   kernel command line.
>>
>>   Alternatively, each supported anonymous THP size can be controlled by
>> -passing ``thp_anon=<size>,<size>[KMG]:<state>;<size>-<size>[KMG]:<state>``,
>> +passing ``thp_anon=<size>[KMG],<size>[KMG]:<state>;<size>[KMG]-<size>[KMG]:<state>``,
>>   where ``<size>`` is the THP size (must be a power of 2 of PAGE_SIZE and
>>   supported anonymous THP)  and ``<state>`` is one of ``always``, ``madvise``,
>>   ``never`` or ``inherit``.
>> --
>> 2.46.2
>>
> 
> Thanks
> Barry