diff --git a/mm/mremap.c b/mm/mremap.c
index a39b7b91be46..93adddecf978 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 #include <linux/slab.h>
 #include <linux/shm.h>
+#include <linux/ksm.h>
 #include <linux/mman.h>
 #include <linux/swap.h>
 #include <linux/capability.h>
@@ -182,6 +183,17 @@ static unsigned long move_vma(struct vm_area_struct *vma,
 	if (mm->map_count >= sysctl_max_map_count - 3)
 		return -ENOMEM;
 
+	/*
+	 * Advise KSM to break any KSM pages in the area to be moved:
+	 * it would be confusing if they were to turn up at the new
+	 * location, where they happen to coincide with different KSM
+	 * pages recently unmapped.  But leave vma->vm_flags as it was,
+	 * so KSM can come around to merge on vma and new_vma afterwards.
+	 */
+	if (ksm_madvise(vma, old_addr, old_addr + old_len,
+						MADV_UNMERGEABLE, &vm_flags))
+		return -ENOMEM;
+
 	new_pgoff = vma->vm_pgoff + ((old_addr - vma->vm_start) >> PAGE_SHIFT);
 	new_vma = copy_vma(&vma, new_addr, new_len, new_pgoff);
 	if (!new_vma)