Release memory cache after build_op_func_list in interpretercore (#46670)

paddle/fluid/framework/new_executor/interpretercore_util.cc

@@ -744,6 +744,12 @@ void build_op_func_list(const platform::Place& place,
 
     interpreter::LogDeviceMemoryStats(place);
   }
+
+  // NOTE(Ruibiao): Release memory cache to avoid memory fragments in Allocator.
+  // It reduce about 10% memory usage for V100 8-GPU training of
+  // transformer_base_bs4096_amp_fp16 and transformer_base_bs4096_pure_fp16
+  // model.
+  memory::Release(place);
 }
 
 void add_fetch(const std::vector<std::string>& fetch_names,