linux-kernel - [PATCH v2 07/11] mm: shmem: drop has_transparent

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Message-ID: <66846ee3aec32c04d20bc7e0e823ba21d4ef278c.1770675272.git.luizcap@redhat.com>
Date: Mon,  9 Feb 2026 17:14:29 -0500
From: Luiz Capitulino <luizcap@...hat.com>
To: linux-kernel@...r.kernel.org,
	linux-mm@...ck.org,
	david@...nel.org,
	baolin.wang@...ux.alibaba.com
Cc: ryan.roberts@....com,
	akpm@...ux-foundation.org,
	lorenzo.stoakes@...cle.com
Subject: [PATCH v2 07/11] mm: shmem: drop has_transparent_hugepage() usage

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@...hat.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 */
-- 
2.53.0