Spread blueberry pie filing into greased 8 x 8-inch baking pan. Arrange pear halves over the blueberries, rounded sides up. In a food processor container, combine oatmeal and margarine; process until combined and crumbly. Sprinkle oatmeal mixture over pears in pan. Bake at 400°F for 45 to 55 minutes or until mixture is bubbly and topping is golden.