1 files changed, 2 insertions, 2 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 56eb871c32d0..b6d74b3dbbc2 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -570,9 +570,9 @@ again:			remove_next = 1 + (end > next->vm_end);
 
         /*
          * When changing only vma->vm_end, we don't really need
-         * anon_vma lock: but is that case worth optimizing out?
+         * anon_vma lock.
          */
-        if (vma->anon_vma)
+        if (vma->anon_vma && (insert || importer || start != vma->vm_start))
                 anon_vma = vma->anon_vma;
         if (anon_vma) {
                 spin_lock(&anon_vma->lock);