Logic on whether we can reap pages from the VMA should match what we
have in madvise_dontneed(). In particular, we should skip, VM_PFNMAP
VMAs, but we don't now.
Let's just extract condition on which we can shoot down pagesi from a
VMA with MADV_DONTNEED into separate function and use it in both places.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
---
mm/internal.h | 5 +++++
mm/madvise.c | 4 +++-
mm/oom_kill.c | 9 +--------
3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/mm/internal.h b/mm/internal.h
index 44d68895a9b9..7430628bff34 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -41,6 +41,11 @@ 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,
diff --git a/mm/madvise.c b/mm/madvise.c
index aa4c502caecb..c53d8da9c8e6 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -24,6 +24,8 @@
#include <asm/tlb.h>
+#include "internal.h"
+
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
* take mmap_sem for writing. Others, which simply traverse vmas, need
@@ -473,7 +475,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
*prev = vma;
- if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
+ if (!can_madv_dontneed_vma(vma))
return -EINVAL;
zap_page_range(vma, start, end - start);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 96a53ab0c9eb..b6d8ac4948db 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -508,14 +508,7 @@ static bool __oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
tlb_gather_mmu(&tlb, mm, 0, -1);
for (vma = mm->mmap ; vma; vma = vma->vm_next) {
- if (is_vm_hugetlb_page(vma))
- continue;
-
- /*
- * mlocked VMAs require explicit munlocking before unmap.
- * Let's keep it simple here and skip such VMAs.
- */
- if (vma->vm_flags & VM_LOCKED)
+ if (!can_madv_dontneed_vma(vma))
continue;
/*
--
2.10.2
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