On 2/10/26 6:14 AM, Luiz Capitulino wrote:
> 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@redhat.com>
> ---
Looks reasonable to me. Thanks.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> 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 */