refine feed_op

paddle/operators/feed_op.cc

@@ -52,7 +52,11 @@ class FeedOp : public framework::OperatorBase {
     platform::DeviceContextPool &pool = platform::DeviceContextPool::Instance();
     auto &dev_ctx = *pool.Get(place);
 
-    framework::Copy(feed_item, place, dev_ctx, out_item);
+    if (platform::is_same_place(feed_item.place(), place)) {
+      out_item->ShareDataWith(feed_item);
+    } else {
+      framework::Copy(feed_item, place, dev_ctx, out_item);
+    }
     out_item->set_lod(feed_item.lod());
   }
 };