Benchmark: Revision - Add wait time option to resolve mem-bw unstable issue (#438)

**Description**
Add wait time option to resolve mem-bw unstable issue.

superbench/benchmarks/micro_benchmarks/cuda_memory_bw_performance.py

@@ -33,6 +33,13 @@ class CudaMemBwBenchmark(MemBwBenchmark):
             default=False,
             help='Enable shmoo mode for bandwidthtest.',
         )
+        self._parser.add_argument(
+            '--sleep',
+            type=int,
+            default=0,
+            required=False,
+            help='The seconds will be sleeped between each bandwidthtest command.',
+        )
 
     def _preprocess(self):
         """Preprocess/preparation operations before the benchmarking.
@@ -52,6 +59,8 @@ class CudaMemBwBenchmark(MemBwBenchmark):
             if self._args.memory == 'pinned':
                 command += ' memory=pinned'
             command += ' --csv'
+            if self._args.sleep != 0:
+                command += f' && sleep {self._args.sleep}'
             self._commands.append(command)
 
         return True

tests/benchmarks/micro_benchmarks/test_cuda_memory_bw_performance.py

@@ -57,3 +57,18 @@ class CudaMemBwTest(BenchmarkTestCase, unittest.TestCase):
             assert (metric in benchmark.result)
             assert (len(benchmark.result[metric]) == 1)
             assert (isinstance(benchmark.result[metric][0], numbers.Number))
+
+        benchmark = benchmark_class(benchmark_name, parameters='--memory=pinned --sleep 3')
+
+        ret = benchmark._preprocess()
+        assert (ret is True)
+        assert (benchmark.return_code == ReturnCode.SUCCESS)
+
+        # Check command list
+        expected_command = [
+            'bandwidthTest --htod memory=pinned --csv && sleep 3',
+            'bandwidthTest --dtoh memory=pinned --csv && sleep 3', 'bandwidthTest --dtod memory=pinned --csv && sleep 3'
+        ]
+        for i in range(len(expected_command)):
+            command = benchmark._bin_name + benchmark._commands[i].split(benchmark._bin_name)[1]
+            assert (command == expected_command[i])