mm: shmem: refactor thpsize_shmem_enabled_store() with sysfs_match_string()

Patch series "refactors thpsize_shmem_enabled_store() and
thpsize_shmem_enabled_show()", v4.


This patch (of 2):

Inspired by commit 82d9ff648c6c ("mm: huge_memory: refactor
anon_enabled_store() with set_anon_enabled_mode()"), refactor
thpsize_shmem_enabled_store() using sysfs_match_string().  This eliminates
the duplicated spin_lock/unlock(), set/clear_bit(), calls across all
branches, reducing code duplication.

Behavioral change:
Call start_stop_khugepaged() only when the mode actually changes.
If unchanged, call set_recommended_min_free_kbytes() to preserve
legacy watermark behavior. This avoids unnecessary khugepaged restarts.

Tested with selftests ./run_kselftest.sh -t mm:ksft_thp.sh,
all test cases passed.

Link: https://lore.kernel.org/20260525102700.68707-1-ranxiaokai627@163.com
Link: https://lore.kernel.org/20260525102700.68707-2-ranxiaokai627@163.com
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Lance Yang <lance.yang@linux.dev>
Acked-by: David Hildenbrand (arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Cc: Breno Leitao <leitao@debian.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions