[PATCH v2 07/11] mm: shmem: drop has_transparent_hugepage() usage

From: Luiz Capitulino

Date: Mon Feb 09 2026 - 17:17:03 EST


Shmem performs two kinds of has_transparent_hugepage() usage:

1. shmem_parse_one() and shmem_init(): since the calls to
has_transparent_hugepage() are protected by #ifdef
CONFIG_TRANSPARENT_HUGEPAGE, this actually checks if the CPU supports
PMD-sized pages. This is irrelevant for shmem as it supports mTHP

2. shmem_parse_huge(): This is checking if THP is enabled and on
architectures that implement has_transparent_hugepage(), this also
checks if the CPU supports PMD-sized pages

While it's necessary to check if CONFIG_TRANSPARENT_HUGEPAGE is enabled,
shmem can determine mTHP size support at folio allocation time.
Therefore, drop has_transparent_hugepage() usage while keeping the
CONFIG_TRANSPARENT_HUGEPAGE checks.

Signed-off-by: Luiz Capitulino <luizcap@xxxxxxxxxx>
---
mm/shmem.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 79af5f9f8b90..32529586cd78 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -689,7 +689,7 @@ static int shmem_parse_huge(const char *str)
else
return -EINVAL;

- if (!has_transparent_hugepage() &&
+ if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
huge != SHMEM_HUGE_NEVER && huge != SHMEM_HUGE_DENY)
return -EINVAL;

@@ -4678,8 +4678,7 @@ static int shmem_parse_one(struct fs_context *fc, struct fs_parameter *param)
case Opt_huge:
ctx->huge = result.uint_32;
if (ctx->huge != SHMEM_HUGE_NEVER &&
- !(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) &&
- has_transparent_hugepage()))
+ !IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
goto unsupported_parameter;
ctx->seen |= SHMEM_SEEN_HUGE;
break;
@@ -5463,7 +5462,7 @@ void __init shmem_init(void)
#endif

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- if (has_transparent_hugepage() && shmem_huge > SHMEM_HUGE_DENY)
+ if (shmem_huge > SHMEM_HUGE_DENY)
SHMEM_SB(shm_mnt->mnt_sb)->huge = shmem_huge;
else
shmem_huge = SHMEM_HUGE_NEVER; /* just in case it was patched */
--
2.53.0