[PATCH v5 0/5] mm: add more kernel parameters to control mTHP

[Maíra Canal]

This series introduces four patches related to the kernel parameters
controlling mTHP and a fifth patch replacing `strcpy()` for `strscpy()`
in the file `mm/huge_memory.c`.

The first patch is a straightforward documentation update, correcting
the format of the kernel parameter ``thp_anon=``.

The second, third, and fourth patches focus on controlling THP support for
shmem via the kernel command line. The second patch introduces a parameter to
control the global default huge page allocation policy for the internal
shmem mount. The third patch moves a piece of code to a shared header to ease
the implementation of the fourth patch. Finally, the fourth patch implements
a parameter similar to ``thp_anon=``, but for shmem.

The goal of these changes is to simplify the configuration of systems that
rely on mTHP support for shmem. For instance, a platform with a GPU that
benefits from huge pages may want to enable huge pages for shmem. Having
these kernel parameters streamlines the configuration process and ensures
consistency across setups.

Let me know your thoughts.

v1 -> v2: https://lore.kernel.org/linux-mm/20241027175743.1056710-1-mcanal@igalia.com/T/

* [1/3] s/fix the format/fix the doc in the commit's subject (Barry Song & David Hildenbrand)
* [1/3] Add Barry's A-b to PATCH 1/3 (Barry Song)
* [1/3] s/64KB/64K (David Hildenbrand)
* [1/3] Add David's A-b to PATCH 1/3 (David Hildenbrand)
* [2/3] Create the function `shmem_valid_huge()` to reduce code-duplication (Baolin Wang)
* [3/4] New PATCH: generalize the function `setup_thp_anon()` and add it to common file
* [4/4] Fix typo in the documentation: s/shmem_anon/thp_shmem (Barry Song)
* [4/4] Reduce code-duplication (Barry Song)

v2 -> v3: https://lore.kernel.org/linux-mm/20241029002324.1062723-1-mcanal@igalia.com/T/

* [2/4] Apply Wang's suggestion (Baolin Wang)
* [3/4] Delete PATCH 3/4 from v2 and implement ``thp_shmem=`` just like in v1 (Barry Song)
* [4/4] New PATCH: "mm: huge_memory: Use strscpy() instead of strcpy()"

v3 -> v4: https://lore.kernel.org/linux-mm/20241030130308.1066299-1-mcanal@igalia.com/T/

* [2/5] Improve commit message by including details about the use of the kernel parameter (Andrew Morton)
* [2/5] Add Baolin's R-b to PATCH 2/5 (Baolin Wang)
* [2/5] Add David's R-b to PATCH 2/5 (David Hildenbrand)
* [3/5] New PATCH: "mm: move ``get_order_from_str()`` to internal.h" (Barry Song & David Hildenbrand)
* [4/5] Improve commit message by including details about the use of the kernel parameter (Andrew Morton)
* [5/5] Add Lance's R-b to PATCH 5/5 (Lance Yang)

v4 -> v5: https://lore.kernel.org/linux-mm/20241101164313.1073238-2-mcanal@igalia.com/T/

* [3/5] Don't use personal e-mail address (Maíra Canal)

Best Regards,
- Maíra

Maíra Canal (5):
  mm: fix docs for the kernel parameter ``thp_anon=``
  mm: shmem: control THP support through the kernel command line
  mm: move ``get_order_from_str()`` to internal.h
  mm: shmem: override mTHP shmem default with a kernel parameter
  mm: huge_memory: Use strscpy() instead of strcpy()

 .../admin-guide/kernel-parameters.txt         |  19 +-
 Documentation/admin-guide/mm/transhuge.rst    |  25 ++-
 mm/huge_memory.c                              |  42 ++---
 mm/internal.h                                 |  22 +++
 mm/shmem.c                                    | 177 +++++++++++++++---
 5 files changed, 234 insertions(+), 51 deletions(-)

-- 
2.46.2