[Core] Adding Priority Scheduling (#5958)

vllm/config.py

@@ -961,7 +961,7 @@ class SchedulerConfig:
             workers instead of an entire data. It should be enabled only
             when SPMD worker architecture is enabled. I.e.,
             VLLM_USE_RAY_SPMD_WORKER=1
-
+        policy: The scheduling policy to use. "fcfs" (default) or "priority".
     """
 
     def __init__(self,
@@ -977,7 +977,8 @@ class SchedulerConfig:
                  preemption_mode: Optional[str] = None,
                  num_scheduler_steps: int = 1,
                  multi_step_stream_outputs: bool = False,
-                 send_delta_data: bool = False) -> None:
+                 send_delta_data: bool = False,
+                 policy: str = "fcfs") -> None:
         if max_num_batched_tokens is None:
             if enable_chunked_prefill:
                 # It is the values that have the best balance between ITL
@@ -1019,6 +1020,7 @@ class SchedulerConfig:
         self.num_scheduler_steps = num_scheduler_steps
         self.multi_step_stream_outputs = multi_step_stream_outputs
         self.send_delta_data = send_delta_data
+        self.policy = policy
         self._verify_args()
 
     def _verify_args(self) -> None: