[Misc][TPU] Support TPU in initialize_ray_cluster (#6812)

Author: WoosukKwon

vllm/executor/ray_utils.py

@@ -3,7 +3,7 @@
 from vllm.config import ParallelConfig
 from vllm.logger import init_logger
 from vllm.sequence import ExecuteModelRequest
-from vllm.utils import get_ip, is_hip, is_xpu
+from vllm.utils import get_ip, is_hip, is_tpu, is_xpu
 from vllm.worker.worker_base import WorkerWrapperBase
 
 logger = init_logger(__name__)
@@ -93,32 +93,38 @@ def initialize_ray_cluster(
         # Placement group is already set.
         return
 
+    device_str = "GPU" if not is_tpu() else "TPU"
     # Create placement group for worker processes
     current_placement_group = ray.util.get_current_placement_group()
     if current_placement_group:
         # We are in a placement group
         bundles = current_placement_group.bundle_specs
         # Verify that we can use the placement group.
-        gpu_bundles = 0
+        device_bundles = 0
         for bundle in bundles:
-            bundle_gpus = bundle.get("GPU", 0)
-            if bundle_gpus > 1:
+            bundle_devices = bundle.get(device_str, 0)
+            if bundle_devices > 1:
                 raise ValueError(
-                    "Placement group bundle cannot have more than 1 GPU.")
-            if bundle_gpus:
-                gpu_bundles += 1
-        if parallel_config.world_size > gpu_bundles:
+                    "Placement group bundle cannot have more than 1 "
+                    f"{device_str}.")
+            if bundle_devices:
+                device_bundles += 1
+        if parallel_config.world_size > device_bundles:
             raise ValueError(
-                "The number of required GPUs exceeds the total number of "
-                "available GPUs in the placement group.")
+                f"The number of required {device_str}s exceeds the total "
+                f"number of available {device_str}s in the placement group."
+                f"Required number of devices: {parallel_config.world_size}. "
+                f"Total number of devices: {device_bundles}.")
     else:
-        num_gpus_in_cluster = ray.cluster_resources().get("GPU", 0)
-        if parallel_config.world_size > num_gpus_in_cluster:
+        num_devices_in_cluster = ray.cluster_resources().get(device_str, 0)
+        if parallel_config.world_size > num_devices_in_cluster:
             raise ValueError(
-                "The number of required GPUs exceeds the total number of "
-                "available GPUs in the cluster.")
+                f"The number of required {device_str}s exceeds the total "
+                f"number of available {device_str}s in the placement group.")
         # Create a new placement group
-        placement_group_specs = ([{"GPU": 1}] * parallel_config.world_size)
+        placement_group_specs = ([{
+            device_str: 1
+        }] * parallel_config.world_size)
         current_placement_group = ray.util.placement_group(
             placement_group_specs)
         # Wait until PG is ready - this will block until all