diff --git a/mm/shmem.c b/mm/shmem.c
index 578eceafba4a743c1aa474d9b44c9d52550b8243..b2a35ebf071a2162dcfd32896c18970b9a8af322 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -674,8 +674,16 @@ static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end)
 		 * generic_delete_inode did it, before we lowered next_index.
 		 * Also, though shmem_getpage checks i_size before adding to
 		 * cache, no recheck after: so fix the narrow window there too.
+		 *
+		 * Recalling truncate_inode_pages_range and unmap_mapping_range
+		 * every time for punch_hole (which never got a chance to clear
+		 * SHMEM_PAGEIN at the start of vmtruncate_range) is expensive,
+		 * yet hardly ever necessary: try to optimize them out later.
 		 */
 		truncate_inode_pages_range(inode->i_mapping, start, end);
+		if (punch_hole)
+			unmap_mapping_range(inode->i_mapping, start,
+							end - start, 1);
 	}
 
 	spin_lock(&info->lock);