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/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 @@ 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;
madvise_userfault_dontneed(vma, prev, start, end);