+ mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages.patch added to mm-hotfixes-unstable branch

+ mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm/shmem: Inline shmem_is_huge() for disabled transparent hugepages
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Sumanth Korikkar <sumanthk@linux.ibm.com>
Subject: mm/shmem: Inline shmem_is_huge() for disabled transparent hugepages
Date: Tue, 9 Apr 2024 17:54:07 +0200

In order to  minimize code size (CONFIG_CC_OPTIMIZE_FOR_SIZE=y),
compiler might choose to make a regular function call (out-of-line) for
shmem_is_huge() instead of inlining it. When transparent hugepages are
disabled (CONFIG_TRANSPARENT_HUGEPAGE=n), it can cause compilation
error.

mm/shmem.c: In function `shmem_getattr':
./include/linux/huge_mm.h:383:27: note: in expansion of macro `BUILD_BUG'
  383 | #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
      |                           ^~~~~~~~~
mm/shmem.c:1148:33: note: in expansion of macro `HPAGE_PMD_SIZE'
 1148 |                 stat->blksize = HPAGE_PMD_SIZE;

To prevent the possible error, always inline shmem_is_huge() when
transparent hugepages are disabled.

Link: https://lkml.kernel.org/r/20240409155407.2322714-1-sumanthk@linux.ibm.com
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/shmem_fs.h |    9 +++++++++
 mm/shmem.c               |    6 ------
 2 files changed, 9 insertions(+), 6 deletions(-)

--- a/include/linux/shmem_fs.h~mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages
+++ a/include/linux/shmem_fs.h
@@ -110,8 +110,17 @@ extern struct page *shmem_read_mapping_p
 extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
 int shmem_unuse(unsigned int type);
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 extern bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
 			  struct mm_struct *mm, unsigned long vm_flags);
+#else
+static __always_inline bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
+					  struct mm_struct *mm, unsigned long vm_flags)
+{
+	return false;
+}
+#endif
+
 #ifdef CONFIG_SHMEM
 extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
 #else
--- a/mm/shmem.c~mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages
+++ a/mm/shmem.c
@@ -748,12 +748,6 @@ static long shmem_unused_huge_count(stru
 
 #define shmem_huge SHMEM_HUGE_DENY
 
-bool shmem_is_huge(struct inode *inode, pgoff_t index, bool shmem_huge_force,
-		   struct mm_struct *mm, unsigned long vm_flags)
-{
-	return false;
-}
-
 static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo,
 		struct shrink_control *sc, unsigned long nr_to_split)
 {
_

Patches currently in -mm which might be from sumanthk@linux.ibm.com are

mm-shmem-inline-shmem_is_huge-for-disabled-transparent-hugepages.patch