[RFC V2 12/12] mm: Tag VMA with VM_CDM flag explicitly during mbind(MPOL_BIND)

[Anshuman Khandual]

Mark all the applicable VMAs with VM_CDM explicitly during mbind(MPOL_BIND)
call if the user provided nodemask has a CDM node.

Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
 mm/mempolicy.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 78e095b..4482140 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -175,6 +175,16 @@ static void mpol_relative_nodemask(nodemask_t *ret, const nodemask_t *orig,
 }
 
 #ifdef CONFIG_COHERENT_DEVICE
+static inline void set_vm_cdm(struct vm_area_struct *vma)
+{
+	vma->vm_flags |= VM_CDM;
+}
+
+static inline void clr_vm_cdm(struct vm_area_struct *vma)
+{
+	vma->vm_flags &= ~VM_CDM;
+}
+
 static void mark_vma_cdm(nodemask_t *nmask,
 		struct page *page, struct vm_area_struct *vma)
 {
@@ -191,6 +201,9 @@ static void mark_vma_cdm(nodemask_t *nmask,
 		vma->vm_flags |= VM_CDM;
 }
 #else
+static inline void set_vm_cdm(struct vm_area_struct *vma) { }
+static inline void clr_vm_cdm(struct vm_area_struct *vma) { }
+
 static void mark_vma_cdm(nodemask_t *nmask,
 		struct page *page, struct vm_area_struct *vma)
 {
@@ -770,6 +783,10 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 		vmstart = max(start, vma->vm_start);
 		vmend   = min(end, vma->vm_end);
 
+		if ((new_pol->mode == MPOL_BIND)
+			&& nodemask_has_cdm(new_pol->v.nodes))
+			set_vm_cdm(vma);
+
 		if (mpol_equal(vma_policy(vma), new_pol))
 			continue;
 
-- 
2.9.3