Multi GPU arguments fixes

keras_retinanet/bin/evaluate.py

@@ -99,7 +99,7 @@ def parse_args(args):
     parser.add_argument('model',              help='Path to RetinaNet model.')
     parser.add_argument('--convert-model',    help='Convert the model to an inference model (ie. the input is a training model).', action='store_true')
     parser.add_argument('--backbone',         help='The backbone of the model.', default='resnet50')
-    parser.add_argument('--gpu',              help='Id of the GPU to use (as reported by nvidia-smi).', type=int)
+    parser.add_argument('--gpu',              help='Id of the GPU to use (as reported by nvidia-smi).')
     parser.add_argument('--score-threshold',  help='Threshold on score to filter detections with (defaults to 0.05).', default=0.05, type=float)
     parser.add_argument('--iou-threshold',    help='IoU Threshold to count for a positive detection (defaults to 0.5).', default=0.5, type=float)
     parser.add_argument('--max-detections',   help='Max Detections per image (defaults to 100).', default=100, type=int)

keras_retinanet/bin/train.py

@@ -426,7 +426,7 @@ def csv_list(string):
     group.add_argument('--no-weights',        help='Don\'t initialize the model with any weights.', dest='imagenet_weights', action='store_const', const=False)
     parser.add_argument('--backbone',         help='Backbone model used by retinanet.', default='resnet50', type=str)
     parser.add_argument('--batch-size',       help='Size of the batches.', default=1, type=int)
-    parser.add_argument('--gpu',              help='Id of the GPU to use (as reported by nvidia-smi).', type=int)
+    parser.add_argument('--gpu',              help='Id of the GPU to use (as reported by nvidia-smi).')
     parser.add_argument('--multi-gpu',        help='Number of GPUs to use for parallel processing.', type=int, default=0)
     parser.add_argument('--multi-gpu-force',  help='Extra flag needed to enable (experimental) multi-gpu support.', action='store_true')
     parser.add_argument('--initial-epoch',    help='Epoch from which to begin the train, useful if resuming from snapshot.', type=int, default=0)

keras_retinanet/utils/gpu.py

@@ -18,23 +18,26 @@
 
 
 def setup_gpu(gpu_id):
-    if gpu_id == 'cpu' or gpu_id == -1:
+    try:
+        visible_gpu_indices = [int(id) for id in gpu_id.split(',')]
+        available_gpus = tf.config.list_physical_devices('GPU')
+        visible_gpus = [gpu for idx, gpu in enumerate(available_gpus) if idx in visible_gpu_indices]
+
+        if visible_gpus:
+            try:
+                # Currently, memory growth needs to be the same across GPUs.
+                for gpu in available_gpus:
+                    tf.config.experimental.set_memory_growth(gpu, True)
+
+                # Use only the selcted gpu.
+                tf.config.set_visible_devices(visible_gpus, 'GPU')
+            except RuntimeError as e:
+                # Visible devices must be set before GPUs have been initialized.
+                print(e)
+
+            logical_gpus = tf.config.list_logical_devices('GPU')
+            print(len(available_gpus), "Physical GPUs,", len(logical_gpus), "Logical GPUs")
+        else:
+            tf.config.set_visible_devices([], 'GPU')
+    except ValueError:
         tf.config.set_visible_devices([], 'GPU')
-        return
-
-    gpus = tf.config.list_physical_devices('GPU')
-    if gpus:
-        # Restrict TensorFlow to only use the first GPU.
-        try:
-            # Currently, memory growth needs to be the same across GPUs.
-            for gpu in gpus:
-                tf.config.experimental.set_memory_growth(gpu, True)
-
-            # Use only the selcted gpu.
-            tf.config.set_visible_devices(gpus[int(gpu_id)], 'GPU')
-        except RuntimeError as e:
-            # Visible devices must be set before GPUs have been initialized.
-            print(e)
-
-        logical_gpus = tf.config.list_logical_devices('GPU')
-        print(len(gpus), "Physical GPUs,", len(logical_gpus), "Logical GPUs")