[PATCH 6.8 138/158] mm/shmem: inline shmem_is_huge() for disabled transparent hugepages

Greg Kroah-Hartman
2024-04-23T21:42:22Z

From: Sumanth Korikkar <sumanthk@linux.ibm.com>

commit 1f737846aa3c45f07a06fa0d018b39e1afb8084a upstream.

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>
Acked-by: David Hildenbrand <david@redhat.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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/shmem_fs.h | 9 +++++++++
mm/shmem.c | 6 ------
2 files changed, 9 insertions(+), 6 deletions(-)

--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -114,8 +114,17 @@ 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
+++ b/mm/shmem.c
@@ -742,12 +742,6 @@ 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)
{