[PATCH v1 1/2] mm: huge_memory: add vma_thp_disabled() and thp_disabled_by_hw()

From: David Hildenbrand
Date: Fri Oct 11 2024 - 06:25:44 EST


From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>

Add vma_thp_disabled() and thp_disabled_by_hw() helpers to be shared by
shmem_allowable_huge_orders() and __thp_vma_allowable_orders().

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
[ rename to vma_thp_disabled(), split out thp_disabled_by_hw() ]
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
include/linux/huge_mm.h | 18 ++++++++++++++++++
mm/huge_memory.c | 13 +------------
mm/shmem.c | 7 +------
3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 67d0ab3c3bba..ef5b80e48599 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -322,6 +322,24 @@ struct thpsize {
(transparent_hugepage_flags & \
(1<<TRANSPARENT_HUGEPAGE_USE_ZERO_PAGE_FLAG))

+static inline bool vma_thp_disabled(struct vm_area_struct *vma,
+ unsigned long vm_flags)
+{
+ /*
+ * Explicitly disabled through madvise or prctl, or some
+ * architectures may disable THP for some mappings, for
+ * example, s390 kvm.
+ */
+ return (vm_flags & VM_NOHUGEPAGE) ||
+ test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags);
+}
+
+static inline bool thp_disabled_by_hw(void)
+{
+ /* If the hardware/firmware marked hugepage support disabled. */
+ return transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED);
+}
+
unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags);
unsigned long thp_get_unmapped_area_vmflags(struct file *filp, unsigned long addr,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 87b49ecc7b1e..2fb328880b50 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -109,18 +109,7 @@ unsigned long __thp_vma_allowable_orders(struct vm_area_struct *vma,
if (!vma->vm_mm) /* vdso */
return 0;

- /*
- * Explicitly disabled through madvise or prctl, or some
- * architectures may disable THP for some mappings, for
- * example, s390 kvm.
- * */
- if ((vm_flags & VM_NOHUGEPAGE) ||
- test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))
- return 0;
- /*
- * If the hardware/firmware marked hugepage support disabled.
- */
- if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
+ if (thp_disabled_by_hw() || vma_thp_disabled(vma, vm_flags))
return 0;

/* khugepaged doesn't collapse DAX vma, but page fault is fine. */
diff --git a/mm/shmem.c b/mm/shmem.c
index 4f11b5506363..c5adb987b23c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1664,12 +1664,7 @@ unsigned long shmem_allowable_huge_orders(struct inode *inode,
loff_t i_size;
int order;

- if (vma && ((vm_flags & VM_NOHUGEPAGE) ||
- test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)))
- return 0;
-
- /* If the hardware/firmware marked hugepage support disabled. */
- if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_UNSUPPORTED))
+ if (thp_disabled_by_hw() || (vma && vma_thp_disabled(vma, vm_flags)))
return 0;

global_huge = shmem_huge_global_enabled(inode, index, write_end,
--
2.46.1