Extend 'mm/thp: add flag to enforce sysfs THP in
hugepage_vma_check()' to shmem, allowing callers to ignore
/sys/kernel/transparent_hugepage/shmem_enabled and tmpfs huge= mount.
This is intended to be used by MADV_COLLAPSE, and the rationale is
analogous to the anon/file case: MADV_COLLAPSE is not coupled to
directives that advise the kernel's decisions on when THPs should be
considered eligible. shmem/tmpfs always claims large folio support,
regardless of sysfs or mount options.
Signed-off-by: Zach O'Keefe <zokeefe@xxxxxxxxxx>
---
include/linux/shmem_fs.h | 10 ++++++----
mm/huge_memory.c | 2 +-
mm/shmem.c | 18 +++++++++---------
3 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index ff0b990de83d..f5e9b01dbf4c 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -92,11 +92,13 @@ extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping,
extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end);
int shmem_unuse(unsigned int type);
-extern bool shmem_is_huge(struct vm_area_struct *vma,
- struct inode *inode, pgoff_t index);
-static inline bool shmem_huge_enabled(struct vm_area_struct *vma)
+extern bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode,
+ pgoff_t index, bool shmem_huge_force);
+static inline bool shmem_huge_enabled(struct vm_area_struct *vma,
+ bool shmem_huge_force)
{
- return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff);
+ return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff,
+ shmem_huge_force);
}
extern unsigned long shmem_swap_usage(struct vm_area_struct *vma);
extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 88d98241a635..b3acc8e3046d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -119,7 +119,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags,
* own flags.
*/
if (!in_pf && shmem_file(vma->vm_file))
- return shmem_huge_enabled(vma);
+ return shmem_huge_enabled(vma, !enforce_sysfs);
/* Enforce sysfs THP requirements as necessary */
if (enforce_sysfs &&
diff --git a/mm/shmem.c b/mm/shmem.c
index 42e5888bf84d..b9bab1abf142 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -472,20 +472,20 @@ static bool shmem_confirm_swap(struct address_space *mapping,
static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER;
-bool shmem_is_huge(struct vm_area_struct *vma,
- struct inode *inode, pgoff_t index)
+bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode,
+ pgoff_t index, bool shmem_huge_force)
{
loff_t i_size;
if (!S_ISREG(inode->i_mode))
return false;
- if (shmem_huge == SHMEM_HUGE_DENY)
- return false;
if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) ||
test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
return false;
- if (shmem_huge == SHMEM_HUGE_FORCE)
+ if (shmem_huge == SHMEM_HUGE_FORCE || shmem_huge_force)
return true;
+ if (shmem_huge == SHMEM_HUGE_DENY)
+ return false;
switch (SHMEM_SB(inode->i_sb)->huge) {
case SHMEM_HUGE_ALWAYS:
@@ -680,8 +680,8 @@ static long shmem_unused_huge_count(struct super_block *sb,
#define shmem_huge SHMEM_HUGE_DENY
-bool shmem_is_huge(struct vm_area_struct *vma,
- struct inode *inode, pgoff_t index)
+bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode,
+ pgoff_t index, bool shmem_huge_force)
{
return false;
}
@@ -1069,7 +1069,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns,
STATX_ATTR_NODUMP);
generic_fillattr(&init_user_ns, inode, stat);
- if (shmem_is_huge(NULL, inode, 0))
+ if (shmem_is_huge(NULL, inode, 0, false))
stat->blksize = HPAGE_PMD_SIZE;
if (request_mask & STATX_BTIME) {
@@ -1910,7 +1910,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index,
return 0;
}
- if (!shmem_is_huge(vma, inode, index))
+ if (!shmem_is_huge(vma, inode, index, false))
goto alloc_nohuge;
huge_gfp = vma_thp_gfp_mask(vma);
--
2.37.2.672.g94769d06f0-goog
