oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA

[mirror_ubuntu-artful-kernel.git] / mm / internal.h

diff --git a/mm/internal.h b/mm/internal.h
index 9ad04fc6eefebf15838da349830305ca58caaeb8..8ab72f4374e046e604cc7c5f15049f960f1b864e 100644 (file)
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -43,6 +43,11 @@ int do_swap_page(struct vm_fault *vmf);
 void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
                unsigned long floor, unsigned long ceiling);
 
+static inline bool can_madv_dontneed_vma(struct vm_area_struct *vma)
+{
+       return !(vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP));
+}
+
 void unmap_page_range(struct mmu_gather *tlb,
                             struct vm_area_struct *vma,
                             unsigned long addr, unsigned long end,