oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA
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.
Link: http://lkml.kernel.org/r/20170118122429.43661-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/internal.h b/mm/internal.h
index 9ad04fc..8ab72f4 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -43,6 +43,11 @@
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 7f1490f..b530a49 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -25,6 +25,8 @@
#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
@@ -474,7 +476,7 @@
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;
madvise_userfault_dontneed(vma, prev, start, end);
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index a197724..8256788 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -508,14 +508,7 @@
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;
/*