message: Add a comment and example to show how to run a subset of eager microbenchmarks
diff: @@ -20,6 +20,13 @@ To run CPU benchmarks:
  To run GPU benchmarks:
  bazel run --config=cuda -c opt --copt="-mavx" benchmarks_test -- \
  --benchmarks=.
  +
  +To run a subset of benchmarks using --benchmarks flag.
  +--benchmarks: the list of benchmarks to run. The specified value is interpreted
  +as a regular expression and any benchmark whose name contains a partial match
  +to the regular expression is executed.
  +e.g. --benchmarks=".*matmul*." will run all matmul related benmarks.
  +
  """
  from __future__ import absolute_import
  from __future__ import division
  