From: Mel Gorman <mgorman@suse.de>
Date: Thu, 9 Oct 2014 22:29:36 +0000 (-0700)
Subject: mm: mempolicy: skip inaccessible VMAs when setting MPOL_MF_LAZY
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=2c0346a36cc8ac6cb85ab585964590974c84bdf0;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git

mm: mempolicy: skip inaccessible VMAs when setting MPOL_MF_LAZY

PROT_NUMA VMAs are skipped to avoid problems distinguishing between
present, prot_none and special entries.  MPOL_MF_LAZY is not visible from
userspace since commit a720094ded8c ("mm: mempolicy: Hide MPOL_NOOP and
MPOL_MF_LAZY from userspace for now") but it should still skip VMAs the
same way task_numa_work does.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Hugh Dickins <hughd@google.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 008fb32936eb..e58725aff7e9 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -681,7 +681,9 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		}
 
 		if (flags & MPOL_MF_LAZY) {
-			change_prot_numa(vma, start, endvma);
+			/* Similar to task_numa_work, skip inaccessible VMAs */
+			if (vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))
+				change_prot_numa(vma, start, endvma);
 			goto next;
 		}