Move SchedulerConfig from config/__init__.py to config/scheduler.py (#22626)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

Author: hmellor

vllm/config/__init__.py

@@ -34,6 +34,7 @@
 from vllm.config.compilation import (CompilationConfig, CompilationLevel,
                                      PassConfig)
 from vllm.config.parallel import DistributedExecutorBackend, ParallelConfig
+from vllm.config.scheduler import SchedulerConfig, SchedulerPolicy
 from vllm.config.utils import ConfigType, config
 from vllm.logger import init_logger
 from vllm.model_executor.layers.quantization import QuantizationMethods
@@ -47,15 +48,9 @@
     try_get_tokenizer_config, uses_mrope)
 from vllm.transformers_utils.s3_utils import S3Model
 from vllm.transformers_utils.utils import is_s3, maybe_model_redirect
-# yapf conflicts with isort for this block
-# yapf: disable
-from vllm.utils import (DEFAULT_MAX_NUM_BATCHED_TOKENS,
-                        MULTIMODAL_MODEL_MAX_NUM_BATCHED_TOKENS,
-                        POOLING_MODEL_MAX_NUM_BATCHED_TOKENS, LayerBlockType,
+from vllm.utils import (DEFAULT_MAX_NUM_BATCHED_TOKENS, LayerBlockType,
                         LazyLoader, common_broadcastable_dtype, random_uuid)
 
-# yapf: enable
-
 if TYPE_CHECKING:
     from _typeshed import DataclassInstance
     from transformers.configuration_utils import PretrainedConfig
@@ -1820,313 +1815,6 @@ def __post_init__(self):
             self.ignore_patterns = ["original/**/*"]
 
 
-PreemptionMode = Literal["swap", "recompute"]
-SchedulerPolicy = Literal["fcfs", "priority"]
-
-
-@config
-@dataclass
-class SchedulerConfig:
-    """Scheduler configuration."""
-
-    runner_type: RunnerType = "generate"
-    """The runner type to launch for the model."""
-
-    max_num_batched_tokens: SkipValidation[int] = None  # type: ignore
-    """Maximum number of tokens to be processed in a single iteration.
-
-    This config has no static default. If left unspecified by the user, it will
-    be set in `EngineArgs.create_engine_config` based on the usage context."""
-
-    max_num_seqs: SkipValidation[int] = None  # type: ignore
-    """Maximum number of sequences to be processed in a single iteration.
-
-    This config has no static default. If left unspecified by the user, it will
-    be set in `EngineArgs.create_engine_config` based on the usage context."""
-
-    max_model_len: SkipValidation[int] = None  # type: ignore
-    """Maximum length of a sequence (including prompt and generated text). This
-    is primarily set in `ModelConfig` and that value should be manually
-    duplicated here."""
-
-    max_num_partial_prefills: int = 1
-    """For chunked prefill, the maximum number of sequences that can be
-    partially prefilled concurrently."""
-
-    max_long_partial_prefills: int = 1
-    """For chunked prefill, the maximum number of prompts longer than
-    long_prefill_token_threshold that will be prefilled concurrently. Setting
-    this less than max_num_partial_prefills will allow shorter prompts to jump
-    the queue in front of longer prompts in some cases, improving latency."""
-
-    long_prefill_token_threshold: int = 0
-    """For chunked prefill, a request is considered long if the prompt is
-    longer than this number of tokens."""
-
-    num_lookahead_slots: int = 0
-    """The number of slots to allocate per sequence per
-    step, beyond the known token ids. This is used in speculative
-    decoding to store KV activations of tokens which may or may not be
-    accepted.
-
-    NOTE: This will be replaced by speculative config in the future; it is
-    present to enable correctness tests until then."""
-
-    cuda_graph_sizes: list[int] = field(default_factory=list)
-    """Cuda graph capture sizes
-    1. if none provided, then default set to [min(max_num_seqs * 2, 512)]
-    2. if one value is provided, then the capture list would follow the
-    pattern: [1, 2, 4] + [i for i in range(8, cuda_graph_sizes + 1, 8)]
-    3. more than one value (e.g. 1 2 128) is provided, then the capture list
-    will follow the provided list."""
-
-    delay_factor: float = 0.0
-    """Apply a delay (of delay factor multiplied by previous
-    prompt latency) before scheduling next prompt."""
-
-    enable_chunked_prefill: SkipValidation[bool] = None  # type: ignore
-    """If True, prefill requests can be chunked based
-    on the remaining max_num_batched_tokens."""
-
-    is_multimodal_model: bool = False
-    """True if the model is multimodal."""
-
-    # TODO (ywang96): Make this configurable.
-    max_num_encoder_input_tokens: int = field(init=False)
-    """Multimodal encoder compute budget, only used in V1.
-
-    NOTE: This is not currently configurable. It will be overridden by
-    max_num_batched_tokens in case max multimodal embedding size is larger."""
-
-    # TODO (ywang96): Make this configurable.
-    encoder_cache_size: int = field(init=False)
-    """Multimodal encoder cache size, only used in V1.
-
-    NOTE: This is not currently configurable. It will be overridden by
-    max_num_batched_tokens in case max multimodal embedding size is larger."""
-
-    preemption_mode: Optional[PreemptionMode] = None
-    """Whether to perform preemption by swapping or
-    recomputation. If not specified, we determine the mode as follows:
-    We use recomputation by default since it incurs lower overhead than
-    swapping. However, when the sequence group has multiple sequences
-    (e.g., beam search), recomputation is not currently supported. In
-    such a case, we use swapping instead."""
-
-    num_scheduler_steps: int = 1
-    """Maximum number of forward steps per scheduler call."""
-
-    multi_step_stream_outputs: bool = True
-    """If False, then multi-step will stream outputs at the end of all steps"""
-
-    send_delta_data: bool = False
-    """Private API. If used, scheduler sends delta data to
-    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: SchedulerPolicy = "fcfs"
-    """The scheduling policy to use:\n
-    - "fcfs" means first come first served, i.e. requests are handled in order
-    of arrival.\n
-    - "priority" means requests are handled based on given priority (lower
-    value means earlier handling) and time of arrival deciding any ties)."""
-
-    chunked_prefill_enabled: bool = field(init=False)
-    """True if chunked prefill is enabled."""
-
-    disable_chunked_mm_input: bool = False
-    """If set to true and chunked prefill is enabled, we do not want to
-    partially schedule a multimodal item. Only used in V1
-    This ensures that if a request has a mixed prompt
-    (like text tokens TTTT followed by image tokens IIIIIIIIII) where only
-    some image tokens can be scheduled (like TTTTIIIII, leaving IIIII),
-    it will be scheduled as TTTT in one step and IIIIIIIIII in the next."""
-
-    # scheduler class or path. "vllm.core.scheduler.Scheduler" (default)
-    # or "mod.custom_class".
-    scheduler_cls: Union[str, type[object]] = "vllm.core.scheduler.Scheduler"
-    """The scheduler class to use. "vllm.core.scheduler.Scheduler" is the
-    default scheduler. Can be a class directly or the path to a class of form
-    "mod.custom_class"."""
-
-    disable_hybrid_kv_cache_manager: bool = False
-    """If set to True, KV cache manager will allocate the same size of KV cache
-    for all attention layers even if there are multiple type of attention layers
-    like full attention and sliding window attention.
-    """
-
-    async_scheduling: bool = False
-    """EXPERIMENTAL: If set to True, perform async scheduling. This may help
-    reduce the CPU overheads, leading to better latency and throughput. However,
-    async scheduling is currently not supported with some features such as
-    structured outputs, speculative decoding, and pipeline parallelism.
-    """
-
-    def compute_hash(self) -> str:
-        """
-        WARNING: Whenever a new field is added to this config,
-        ensure that it is included in the factors list if
-        it affects the computation graph.
-
-        Provide a hash that uniquely identifies all the configs
-        that affect the structure of the computation
-        graph from input ids/embeddings to the final hidden states,
-        excluding anything before input ids/embeddings and after
-        the final hidden states.
-        """
-        # no factors to consider.
-        # this config will not affect the computation graph.
-        factors: list[Any] = []
-        hash_str = hashlib.md5(str(factors).encode(),
-                               usedforsecurity=False).hexdigest()
-        return hash_str
-
-    def __post_init__(self) -> None:
-        if self.max_model_len is None:
-            self.max_model_len = 8192
-
-        if self.max_num_seqs is None:
-            self.max_num_seqs = 128
-
-        if self.max_num_batched_tokens is None:
-            if self.enable_chunked_prefill:
-                if self.num_scheduler_steps > 1:
-                    # Multi-step Chunked-Prefill doesn't allow prompt-chunking
-                    # for now. Have max_num_batched_tokens set to max_model_len
-                    # so we don't reject sequences on account of a short
-                    # max_num_batched_tokens.
-                    self.max_num_batched_tokens = max(
-                        self.max_model_len, DEFAULT_MAX_NUM_BATCHED_TOKENS)
-                else:
-                    self.max_num_batched_tokens = (
-                        DEFAULT_MAX_NUM_BATCHED_TOKENS)
-            else:
-                # If max_model_len is too short, use
-                # DEFAULT_MAX_NUM_BATCHED_TOKENS as the default value
-                # for higher throughput.
-                self.max_num_batched_tokens = max(
-                    self.max_model_len, DEFAULT_MAX_NUM_BATCHED_TOKENS)
-
-            if self.runner_type == "pooling":
-                # Choose specific value for higher throughput
-                self.max_num_batched_tokens = max(
-                    self.max_num_batched_tokens,
-                    POOLING_MODEL_MAX_NUM_BATCHED_TOKENS,
-                )
-            if self.is_multimodal_model:
-                # The value needs to be at least the number of multimodal tokens
-                self.max_num_batched_tokens = max(
-                    self.max_num_batched_tokens,
-                    MULTIMODAL_MODEL_MAX_NUM_BATCHED_TOKENS,
-                )
-
-            # When using default settings,
-            # Ensure max_num_batched_tokens does not exceed model limit.
-            # Some models (e.g., Whisper) have embeddings tied to max length.
-            self.max_num_batched_tokens = min(
-                self.max_num_seqs * self.max_model_len,
-                self.max_num_batched_tokens)
-
-        self.max_num_encoder_input_tokens = self.max_num_batched_tokens
-        self.encoder_cache_size = self.max_num_batched_tokens
-
-        if self.enable_chunked_prefill:
-            logger.info(
-                "Chunked prefill is enabled with max_num_batched_tokens=%d.",
-                self.max_num_batched_tokens)
-
-        self.chunked_prefill_enabled = self.enable_chunked_prefill
-        if self.max_num_partial_prefills > 1:
-            if self.long_prefill_token_threshold == 0:
-                self.long_prefill_token_threshold = int(self.max_model_len *
-                                                        0.04)
-
-            logger.info(
-                "Concurrent partial prefills enabled with "
-                "max_num_partial_prefills=%d, max_long_partial_prefills=%d, "
-                "long_prefill_token_threshold=%d",
-                self.max_num_partial_prefills, self.max_long_partial_prefills,
-                self.long_prefill_token_threshold)
-
-        # NOTE: Default set cuda_graph_sizes to [min(max_num_seqs * 2, 512)].
-        # This avoids OOM in tight memory scenarios with small max_num_seqs,
-        # and prevents capture of many large graphs (>512) that would greatly
-        # increase startup time with limited performance benefit.
-        if not self.cuda_graph_sizes:
-            self.cuda_graph_sizes = [min(self.max_num_seqs * 2, 512)]
-
-        if self.async_scheduling:
-            self.scheduler_cls = (
-                "vllm.v1.core.sched.async_scheduler.AsyncScheduler")
-
-    @model_validator(mode='after')
-    def _verify_args(self) -> Self:
-        if (self.max_num_batched_tokens < self.max_model_len
-                and not self.chunked_prefill_enabled):
-            raise ValueError(
-                f"max_num_batched_tokens ({self.max_num_batched_tokens}) is "
-                f"smaller than max_model_len ({self.max_model_len}). "
-                "This effectively limits the maximum sequence length to "
-                "max_num_batched_tokens and makes vLLM reject longer "
-                "sequences. Please increase max_num_batched_tokens or "
-                "decrease max_model_len.")
-
-        if self.max_num_batched_tokens < self.max_num_seqs:
-            raise ValueError(
-                f"max_num_batched_tokens ({self.max_num_batched_tokens}) must "
-                "be greater than or equal to max_num_seqs "
-                f"({self.max_num_seqs}).")
-
-        if self.max_num_batched_tokens > self.max_num_seqs * self.max_model_len:
-            logger.warning(
-                "max_num_batched_tokens (%d) exceeds max_num_seqs "
-                "* max_model_len (%d). This may lead to unexpected behavior.",
-                self.max_num_batched_tokens,
-                self.max_num_seqs * self.max_model_len)
-
-        if self.num_lookahead_slots < 0:
-            raise ValueError(
-                "num_lookahead_slots "
-                f"({self.num_lookahead_slots}) must be greater than or "
-                "equal to 0.")
-
-        if self.num_scheduler_steps < 1:
-            raise ValueError(
-                "num_scheduler_steps "
-                f"({self.num_scheduler_steps}) must be greater than or "
-                "equal to 1.")
-
-        if self.max_num_partial_prefills < 1:
-            raise ValueError(
-                f"max_num_partial_prefills ({self.max_num_partial_prefills}) "
-                "must be greater than or equal to 1.")
-        elif self.max_num_partial_prefills > 1:
-            if not self.chunked_prefill_enabled:
-                raise ValueError("Chunked prefill must be enabled to set "
-                                 "max_num_partial_prefills > 1.")
-
-            if self.long_prefill_token_threshold > self.max_model_len:
-                raise ValueError(
-                    "long_prefill_token_threshold "
-                    f"({self.long_prefill_token_threshold}) cannot be greater "
-                    f"than the max_model_len ({self.max_model_len}).")
-
-        if (self.max_long_partial_prefills
-                < 1) or (self.max_long_partial_prefills
-                         > self.max_num_partial_prefills):
-            raise ValueError(
-                f"max_long_partial_prefills ({self.max_long_partial_prefills}) "
-                "must be greater than or equal to 1 and less than or equal to "
-                f"max_num_partial_prefills ({self.max_num_partial_prefills}).")
-
-        return self
-
-    @property
-    def is_multi_step(self) -> bool:
-        return self.num_scheduler_steps > 1
-
-
 Device = Literal["auto", "cuda", "neuron", "cpu", "tpu", "xpu"]