VOLATILE imply the the pages in the range isn't working set any more
so it's pointless that make them to THP/KSM.
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
---
mm/huge_memory.c | 9 +++++++--
mm/ksm.c | 3 ++-
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 40f17c3..5ddd00e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1477,7 +1477,8 @@ out:
return ret;
}
-#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|VM_SHARED|VM_MAYSHARE)
+#define VM_NO_THP (VM_SPECIAL|VM_MIXEDMAP|VM_HUGETLB|\
+ VM_SHARED|VM_MAYSHARE|VM_VOLATILE)
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
@@ -1641,6 +1642,8 @@ int khugepaged_enter_vma_merge(struct vm_area_struct *vma)
* page fault if needed.
*/
return 0;
+ if (vma->vm_flags & VM_VOLATILE)
+ return 0;
if (vma->vm_ops)
/* khugepaged not yet working on file or special mappings */
return 0;
@@ -1969,6 +1972,8 @@ static void collapse_huge_page(struct mm_struct *mm,
goto out;
if (is_vma_temporary_stack(vma))
goto out;
+ if (vma->vm_flags & VM_VOLATILE)
+ goto out;
VM_BUG_ON(vma->vm_flags & VM_NO_THP);
pgd = pgd_offset(mm, address);
@@ -2196,7 +2201,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
if ((!(vma->vm_flags & VM_HUGEPAGE) &&
!khugepaged_always()) ||
- (vma->vm_flags & VM_NOHUGEPAGE)) {
+ (vma->vm_flags & (VM_NOHUGEPAGE|VM_VOLATILE))) {
skip:
progress++;
continue;
diff --git a/mm/ksm.c b/mm/ksm.c
index ae539f0..2775f59 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -1486,7 +1486,8 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
*/
if (*vm_flags & (VM_MERGEABLE | VM_SHARED | VM_MAYSHARE |
VM_PFNMAP | VM_IO | VM_DONTEXPAND |
- VM_HUGETLB | VM_NONLINEAR | VM_MIXEDMAP))
+ VM_HUGETLB | VM_NONLINEAR | VM_MIXEDMAP |
+ VM_VOLATILE))
return 0; /* just ignore the advice */
#ifdef VM_SAO
--
1.7.9.5
--
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