Move MADV_MERGEABLE part of ksm_madvise() into a dedicated helper since
it will be further used in do_anonymous_page().
This does not bring any functional changes.
Signed-off-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxx>
---
include/linux/ksm.h | 2 ++
mm/ksm.c | 66 ++++++++++++++++++++++++++-------------------
2 files changed, 41 insertions(+), 27 deletions(-)
diff --git a/include/linux/ksm.h b/include/linux/ksm.h
index e48b1e453ff5..bc13f228e2ed 100644
--- a/include/linux/ksm.h
+++ b/include/linux/ksm.h
@@ -21,6 +21,8 @@ struct mem_cgroup;
#ifdef CONFIG_KSM
int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
unsigned long end, int advice, unsigned long *vm_flags);
+int ksm_enter(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long *vm_flags);
int __ksm_enter(struct mm_struct *mm);
void __ksm_exit(struct mm_struct *mm);
diff --git a/mm/ksm.c b/mm/ksm.c
index fc64874dc6f4..a6b0788a3a22 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2450,33 +2450,9 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
switch (advice) {
case MADV_MERGEABLE:
- /*
- * Be somewhat over-protective for now!
- */
- if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE |
- VM_PFNMAP | VM_IO | VM_DONTEXPAND |
- VM_HUGETLB | VM_MIXEDMAP))
- return 0; /* just ignore the advice */
-
- if (vma_is_dax(vma))
- return 0;
-
-#ifdef VM_SAO
- if (*vm_flags & VM_SAO)
- return 0;
-#endif
-#ifdef VM_SPARC_ADI
- if (*vm_flags & VM_SPARC_ADI)
- return 0;
-#endif
-
- if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) {
- err = __ksm_enter(mm);
- if (err)
- return err;
- }
-
- *vm_flags |= VM_MERGEABLE;
+ err = ksm_enter(mm, vma, vm_flags);
+ if (err)
+ return err;
break;
case MADV_UNMERGEABLE:
@@ -2496,6 +2472,42 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
return 0;
}
+int ksm_enter(struct mm_struct *mm, struct vm_area_struct *vma,
+ unsigned long *vm_flags)
+{
+ int err;
+
+ /*
+ * Be somewhat over-protective for now!
+ */
+ if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE |
+ VM_PFNMAP | VM_IO | VM_DONTEXPAND |
+ VM_HUGETLB | VM_MIXEDMAP))
+ return 0; /* just ignore the advice */
+
+ if (vma_is_dax(vma))
+ return 0;
+
+#ifdef VM_SAO
+ if (*vm_flags & VM_SAO)
+ return 0;
+#endif
+#ifdef VM_SPARC_ADI
+ if (*vm_flags & VM_SPARC_ADI)
+ return 0;
+#endif
+
+ if (!test_bit(MMF_VM_MERGEABLE, &mm->flags)) {
+ err = __ksm_enter(mm);
+ if (err)
+ return err;
+ }
+
+ *vm_flags |= VM_MERGEABLE;
+
+ return 0;
+}
+
int __ksm_enter(struct mm_struct *mm)
{
struct mm_slot *mm_slot;
--
2.21.0
