import time from typing import Dict, List, Optional, Tuple, Union import numpy as np import torch import torch.nn as nn from vllm.config import ModelConfig, ParallelConfig, SchedulerConfig from vllm.logger import init_logger from vllm.model_executor import get_model, InputMetadata, SamplingMetadata from vllm.model_executor.parallel_utils.communication_op import ( broadcast_tensor_dict) from vllm.sampling_params import SamplingParams, SamplingType from vllm.sequence import SamplerOutput, SequenceData, SequenceGroupMetadata from vllm.utils import in_wsl logger = init_logger(__name__) KVCache = Tuple[torch.Tensor, torch.Tensor] _PAD_SLOT_ID = -1 # Capture graphs for batch size 1, 2, 4, 8, 16, 24, 32, 40, ..., 256. # NOTE: _get_graph_batch_size needs to be updated if this list is changed. _BATCH_SIZES_TO_CAPTURE = [1, 2, 4] + [8 * i for i in range(1, 33)] class ModelRunner: def __init__( self, model_config: ModelConfig, parallel_config: ParallelConfig, scheduler_config: SchedulerConfig, is_driver_worker: bool = False, ): self.model_config = model_config self.parallel_config = parallel_config self.scheduler_config = scheduler_config self.is_driver_worker = is_driver_worker # model_config can be None in tests/samplers/test_sampler.py. # FIXME(woosuk): This is a hack to make the tests work. Refactor this. self.sliding_window = (model_config.get_sliding_window() if model_config is not None else None) self.model = None self.block_size = None # Set after initial profiling. self.graph_runners: Dict[int, CUDAGraphRunner] = {} self.graph_memory_pool = None # Set during graph capture. self.max_context_len_to_capture = ( self.model_config.max_context_len_to_capture if self.model_config is not None else 0) # When using CUDA graph, the input block tables must be padded to # max_context_len_to_capture. However, creating the block table in # Python can be expensive. To optimize this, we cache the block table # in numpy and only copy the actual input content at every iteration. # The shape of the cached block table will be # (max batch size to capture, max context len to capture / block size). self.graph_block_tables = None # Set after initial profiling. # cache in_wsl result self.in_wsl = in_wsl() def load_model(self) -> None: self.model = get_model(self.model_config) def set_block_size(self, block_size: int) -> None: self.block_size = block_size max_num_blocks = (self.max_context_len_to_capture + block_size - 1) // block_size self.graph_block_tables = np.zeros( (max(_BATCH_SIZES_TO_CAPTURE), max_num_blocks), dtype=np.int32) def _prepare_prompt( self, seq_group_metadata_list: List[SequenceGroupMetadata], ) -> Tuple[torch.Tensor, torch.Tensor, InputMetadata, List[int], List[int]]: assert len(seq_group_metadata_list) > 0 input_tokens: List[List[int]] = [] input_positions: List[List[int]] = [] slot_mapping: List[List[int]] = [] prompt_lens: List[int] = [] context_lens: List[int] = [] subquery_lens: List[int] = [] prefix_block_tables: List[List[int]] = [] for seq_group_metadata in seq_group_metadata_list: assert seq_group_metadata.is_prompt seq_ids = list(seq_group_metadata.seq_data.keys()) assert len(seq_ids) == 1 seq_id = seq_ids[0] seq_data = seq_group_metadata.seq_data[seq_id] prompt_tokens = seq_data.get_token_ids() prompt_len = len(prompt_tokens) prompt_lens.append(prompt_len) prefix_len = 0 prefix = seq_group_metadata.prefix if prefix is not None and prefix.computed: prefix_len = prefix.get_length() prompt_tokens = prompt_tokens[prefix_len:] prefix_block_tables.append(prefix.get_block_numbers()) else: prefix_block_tables.append([]) # actual prompt lens context_lens.append(prefix_len) subquery_lens.append(prompt_len - prefix_len) input_tokens.append(prompt_tokens) # NOTE(woosuk): Here we assume that the first token in the prompt # is always the first token in the sequence. input_positions.append( list(range(prefix_len, prefix_len + len(prompt_tokens)))) if seq_group_metadata.block_tables is None: # During memory profiling, the block tables are not initialized # yet. In this case, we just use a dummy slot mapping. slot_mapping.append([_PAD_SLOT_ID] * prompt_len) continue # Compute the slot mapping. slot_mapping.append([]) block_table = seq_group_metadata.block_tables[seq_id] # Mask the [0, start_idx) tokens of the prompt with _PAD_SLOT_ID, # where start_idx is max(0, prompt_len - sliding_window). # For example, if the prompt len is 10, sliding window is 8, and # block size is 4, the first two tokens are masked and the slot # mapping will be [-1, -1, 2, 3, 4, 5, 6, 7, 0, 1]. start_idx = 0 if self.sliding_window is not None: assert prefix_len == 0, ( "Prefix caching is currently not supported with " "sliding window attention") start_idx = max(0, prompt_len - self.sliding_window) for i in range(prefix_len, prompt_len): if i < start_idx: slot_mapping[-1].append(_PAD_SLOT_ID) continue block_number = block_table[i // self.block_size] block_offset = i % self.block_size slot = block_number * self.block_size + block_offset slot_mapping[-1].append(slot) max_prompt_len = max(subquery_lens) input_tokens = _make_tensor_with_pad(input_tokens, max_prompt_len, pad=0, dtype=torch.long) input_positions = _make_tensor_with_pad(input_positions, max_prompt_len, pad=0, dtype=torch.long) slot_mapping = _make_tensor_with_pad(slot_mapping, max_prompt_len, pad=_PAD_SLOT_ID, dtype=torch.long) context_lens_tensor = torch.tensor(context_lens, dtype=torch.int, device='cuda') # Prepare prefix block tables max_prompt_block_table_len = max(len(t) for t in prefix_block_tables) block_tables = _make_tensor_with_pad( prefix_block_tables, max_len=max_prompt_block_table_len, pad=0, dtype=torch.int, ) start_loc_tensor = torch.arange(0, len(prompt_lens) * max_prompt_len, max_prompt_len, dtype=torch.long, device='cuda') prompt_lens_tensor = torch.tensor(prompt_lens, dtype=torch.long, device='cuda') input_metadata = InputMetadata( is_prompt=True, slot_mapping=slot_mapping, prompt_lens=prompt_lens_tensor, max_seq_len=max_prompt_len, start_loc=start_loc_tensor, max_context_len=None, context_lens=context_lens_tensor, block_tables=block_tables, use_cuda_graph=False, ) return (input_tokens, input_positions, input_metadata, prompt_lens, subquery_lens) def _prepare_decode( self, seq_group_metadata_list: List[SequenceGroupMetadata], ) -> Tuple[torch.Tensor, torch.Tensor, InputMetadata]: assert len(seq_group_metadata_list) > 0 input_tokens: List[List[int]] = [] input_positions: List[List[int]] = [] slot_mapping: List[List[int]] = [] context_lens: List[int] = [] block_tables: List[List[int]] = [] for seq_group_metadata in seq_group_metadata_list: assert not seq_group_metadata.is_prompt seq_ids = list(seq_group_metadata.seq_data.keys()) for seq_id in seq_ids: seq_data = seq_group_metadata.seq_data[seq_id] generation_token = seq_data.get_last_token_id() input_tokens.append([generation_token]) seq_len = seq_data.get_len() position = seq_len - 1 input_positions.append([position]) context_len = seq_len if self.sliding_window is None else min( seq_len, self.sliding_window) context_lens.append(context_len) block_table = seq_group_metadata.block_tables[seq_id] block_number = block_table[position // self.block_size] block_offset = position % self.block_size slot = block_number * self.block_size + block_offset slot_mapping.append([slot]) if self.sliding_window is not None: sliding_window_blocks = (self.sliding_window // self.block_size) block_table = block_table[-sliding_window_blocks:] block_tables.append(block_table) batch_size = len(input_tokens) max_context_len = max(context_lens) use_captured_graph = ( not self.model_config.enforce_eager and batch_size <= _BATCH_SIZES_TO_CAPTURE[-1] and max_context_len <= self.max_context_len_to_capture) if use_captured_graph: # Pad the input tokens, positions, and slot mapping to match the # batch size of the captured graph. graph_batch_size = _get_graph_batch_size(batch_size) assert graph_batch_size >= batch_size for _ in range(graph_batch_size - batch_size): input_tokens.append([]) input_positions.append([]) slot_mapping.append([]) context_lens.append(1) block_tables.append([]) batch_size = graph_batch_size input_tokens = _make_tensor_with_pad(input_tokens, max_len=1, pad=0, dtype=torch.long, device="cuda") input_positions = _make_tensor_with_pad(input_positions, max_len=1, pad=0, dtype=torch.long, device="cuda") slot_mapping = _make_tensor_with_pad(slot_mapping, max_len=1, pad=_PAD_SLOT_ID, dtype=torch.long, device="cuda") context_lens = torch.tensor(context_lens, dtype=torch.int, device="cuda") if use_captured_graph: # The shape of graph_block_tables is # [max batch size, max context len // block size]. input_block_tables = self.graph_block_tables[:batch_size] for i, block_table in enumerate(block_tables): if block_table: input_block_tables[i, :len(block_table)] = block_table block_tables = torch.tensor(input_block_tables, device="cuda") else: max_block_table_len = (max_context_len + self.block_size - 1) // self.block_size block_tables = _make_tensor_with_pad( block_tables, max_len=max_block_table_len, pad=0, dtype=torch.int, device="cuda", ) input_metadata = InputMetadata( is_prompt=False, slot_mapping=slot_mapping, prompt_lens=None, max_seq_len=None, start_loc=None, max_context_len=max_context_len, context_lens=context_lens, block_tables=block_tables, use_cuda_graph=use_captured_graph, ) return input_tokens, input_positions, input_metadata def _prepare_sample( self, seq_group_metadata_list: List[SequenceGroupMetadata], prompt_lens: List[int], subquery_lens: Optional[List[int]], ) -> SamplingMetadata: seq_groups: List[Tuple[List[int], SamplingParams]] = [] selected_token_indices: List[int] = [] selected_token_start_idx = 0 categorized_sample_indices = {t: [] for t in SamplingType} categorized_sample_indices_start_idx = 0 max_subquery_len = max(subquery_lens) if subquery_lens else 1 for i, seq_group_metadata in enumerate(seq_group_metadata_list): seq_ids = list(seq_group_metadata.seq_data.keys()) sampling_params = seq_group_metadata.sampling_params seq_groups.append((seq_ids, sampling_params)) if seq_group_metadata.is_prompt: assert len(seq_ids) == 1 assert subquery_lens is not None subquery_len = subquery_lens[i] if sampling_params.prompt_logprobs is not None: # NOTE: prompt token positions do not need sample, skip categorized_sample_indices_start_idx += subquery_len - 1 categorized_sample_indices[ sampling_params.sampling_type].append( categorized_sample_indices_start_idx) categorized_sample_indices_start_idx += 1 if sampling_params.prompt_logprobs is not None: selected_token_indices.extend( range(selected_token_start_idx, selected_token_start_idx + subquery_len - 1)) selected_token_indices.append(selected_token_start_idx + subquery_len - 1) selected_token_start_idx += max_subquery_len else: num_seqs = len(seq_ids) selected_token_indices.extend( range(selected_token_start_idx, selected_token_start_idx + num_seqs)) selected_token_start_idx += num_seqs categorized_sample_indices[ sampling_params.sampling_type].extend( range(categorized_sample_indices_start_idx, categorized_sample_indices_start_idx + num_seqs)) categorized_sample_indices_start_idx += num_seqs selected_token_indices = _async_h2d(selected_token_indices, dtype=torch.long, pin_memory=not self.in_wsl) categorized_sample_indices = { t: _async_h2d(seq_ids, dtype=torch.int, pin_memory=not self.in_wsl) for t, seq_ids in categorized_sample_indices.items() } seq_data: Dict[int, SequenceData] = {} for seq_group_metadata in seq_group_metadata_list: seq_data.update(seq_group_metadata.seq_data) sampling_metadata = SamplingMetadata( seq_groups=seq_groups, seq_data=seq_data, prompt_lens=prompt_lens, selected_token_indices=selected_token_indices, categorized_sample_indices=categorized_sample_indices, ) return sampling_metadata def prepare_input_tensors( self, seq_group_metadata_list: Optional[List[SequenceGroupMetadata]], ) -> Tuple[torch.Tensor, torch.Tensor, InputMetadata, SamplingMetadata]: if self.is_driver_worker: # NOTE: We assume that all sequences in the group are all prompts or # all decodes. is_prompt = seq_group_metadata_list[0].is_prompt # Prepare input tensors. if is_prompt: (input_tokens, input_positions, input_metadata, prompt_lens, subquery_lens) = self._prepare_prompt(seq_group_metadata_list) else: (input_tokens, input_positions, input_metadata ) = self._prepare_decode(seq_group_metadata_list) subquery_lens = None prompt_lens = [] sampling_metadata = self._prepare_sample(seq_group_metadata_list, prompt_lens, subquery_lens) # Broadcast the metadata. metadata_dict = { "input_tokens": input_tokens, "input_positions": input_positions, "is_prompt": input_metadata.is_prompt, "slot_mapping": input_metadata.slot_mapping, "prompt_lens": input_metadata.prompt_lens, "max_seq_len": input_metadata.max_seq_len, "start_loc": input_metadata.start_loc, "max_context_len": input_metadata.max_context_len, "context_lens": input_metadata.context_lens, "block_tables": input_metadata.block_tables, "use_cuda_graph": input_metadata.use_cuda_graph, "selected_token_indices": sampling_metadata.selected_token_indices, } broadcast_tensor_dict(metadata_dict, src=0) else: metadata_dict = broadcast_tensor_dict(src=0) input_tokens = metadata_dict["input_tokens"] input_positions = metadata_dict["input_positions"] input_metadata = InputMetadata( is_prompt=metadata_dict["is_prompt"], slot_mapping=metadata_dict["slot_mapping"], prompt_lens=metadata_dict["prompt_lens"], max_seq_len=metadata_dict["max_seq_len"], start_loc=metadata_dict["start_loc"], max_context_len=metadata_dict["max_context_len"], context_lens=metadata_dict["context_lens"], block_tables=metadata_dict["block_tables"], use_cuda_graph=metadata_dict["use_cuda_graph"], ) sampling_metadata = SamplingMetadata( seq_groups=None, seq_data=None, prompt_lens=None, selected_token_indices=metadata_dict["selected_token_indices"], categorized_sample_indices=None, perform_sampling=False, ) return input_tokens, input_positions, input_metadata, sampling_metadata @torch.inference_mode() def execute_model( self, seq_group_metadata_list: Optional[List[SequenceGroupMetadata]], kv_caches: List[Tuple[torch.Tensor, torch.Tensor]], ) -> Optional[SamplerOutput]: input_tokens, input_positions, input_metadata, sampling_metadata = ( self.prepare_input_tensors(seq_group_metadata_list)) # Execute the model. if input_metadata.use_cuda_graph: graph_batch_size = input_tokens.shape[0] model_executable = self.graph_runners[graph_batch_size] else: model_executable = self.model hidden_states = model_executable( input_ids=input_tokens, positions=input_positions, kv_caches=kv_caches, input_metadata=input_metadata, ) # Sample the next token. output = self.model.sample( hidden_states=hidden_states, sampling_metadata=sampling_metadata, ) return output @torch.inference_mode() def profile_run(self) -> None: # Enable top-k sampling to reflect the accurate memory usage. vocab_size = self.model_config.get_vocab_size() sampling_params = SamplingParams(top_p=0.99, top_k=vocab_size - 1) max_num_batched_tokens = self.scheduler_config.max_num_batched_tokens max_num_seqs = self.scheduler_config.max_num_seqs # Profile memory usage with max_num_sequences sequences and the total # number of tokens equal to max_num_batched_tokens. seqs: List[SequenceGroupMetadata] = [] for group_id in range(max_num_seqs): seq_len = (max_num_batched_tokens // max_num_seqs + (group_id < max_num_batched_tokens % max_num_seqs)) seq_data = SequenceData([0] * seq_len) seq = SequenceGroupMetadata( request_id=str(group_id), is_prompt=True, seq_data={group_id: seq_data}, sampling_params=sampling_params, block_tables=None, ) seqs.append(seq) # Run the model with the dummy inputs. num_layers = self.model_config.get_num_layers(self.parallel_config) kv_caches = [(None, None)] * num_layers self.execute_model(seqs, kv_caches) torch.cuda.synchronize() return @torch.inference_mode() def capture_model(self, kv_caches: List[KVCache]) -> None: assert not self.model_config.enforce_eager logger.info("Capturing the model for CUDA graphs. This may lead to " "unexpected consequences if the model is not static. To " "run the model in eager mode, set 'enforce_eager=True' or " "use '--enforce-eager' in the CLI.") logger.info("CUDA graphs can take additional 1~3 GiB memory per GPU. " "If you are running out of memory, consider decreasing " "`gpu_memory_utilization` or enforcing eager mode. " "You can also reduce the `max_num_seqs` as needed " "to decrease memory usage.") start_time = time.perf_counter() # Prepare dummy inputs. These will be reused for all batch sizes. max_batch_size = max(_BATCH_SIZES_TO_CAPTURE) input_tokens = torch.zeros(max_batch_size, 1, dtype=torch.long).cuda() input_positions = torch.zeros(max_batch_size, 1, dtype=torch.long).cuda() slot_mapping = torch.empty(max_batch_size, 1, dtype=torch.long).cuda() slot_mapping.fill_(_PAD_SLOT_ID) context_lens = torch.ones(max_batch_size, dtype=torch.int32).cuda() block_tables = torch.from_numpy(self.graph_block_tables).cuda() graph_batch_size = _get_graph_batch_size( self.scheduler_config.max_num_seqs) batch_size_capture_list = [ bs for bs in _BATCH_SIZES_TO_CAPTURE if bs <= graph_batch_size ] # NOTE: Capturing the largest batch size first may help reduce the # memory usage of CUDA graph. for batch_size in reversed(batch_size_capture_list): # Create dummy input_metadata. input_metadata = InputMetadata( is_prompt=False, slot_mapping=slot_mapping[:batch_size], prompt_lens=None, max_seq_len=None, start_loc=None, max_context_len=self.max_context_len_to_capture, context_lens=context_lens[:batch_size], block_tables=block_tables[:batch_size], use_cuda_graph=True, ) graph_runner = CUDAGraphRunner(self.model) graph_runner.capture( input_tokens[:batch_size], input_positions[:batch_size], kv_caches, input_metadata, memory_pool=self.graph_memory_pool, ) self.graph_memory_pool = graph_runner.graph.pool() self.graph_runners[batch_size] = graph_runner end_time = time.perf_counter() elapsed_time = end_time - start_time # This usually takes < 10 seconds. logger.info(f"Graph capturing finished in {elapsed_time:.0f} secs.") class CUDAGraphRunner: def __init__(self, model: nn.Module): self.model = model self.graph = None self.input_buffers: Dict[str, torch.Tensor] = {} self.output_buffers: Dict[str, torch.Tensor] = {} def capture( self, input_ids: torch.Tensor, positions: torch.Tensor, kv_caches: List[KVCache], input_metadata: InputMetadata, memory_pool, ) -> None: assert self.graph is None # Run the model once without capturing the graph. # This is to make sure that the captured graph does not include the # kernel launches for initial benchmarking (e.g., Triton autotune). self.model( input_ids, positions, kv_caches, input_metadata, ) torch.cuda.synchronize() # Capture the graph. self.graph = torch.cuda.CUDAGraph() with torch.cuda.graph(self.graph, pool=memory_pool): hidden_states = self.model( input_ids, positions, kv_caches, input_metadata, ) torch.cuda.synchronize() # Save the input and output buffers. self.input_buffers = { "input_ids": input_ids, "positions": positions, "kv_caches": kv_caches, "slot_mapping": input_metadata.slot_mapping, "context_lens": input_metadata.context_lens, "block_tables": input_metadata.block_tables, } self.output_buffers = {"hidden_states": hidden_states} return def forward( self, input_ids: torch.Tensor, positions: torch.Tensor, kv_caches: List[Tuple[torch.Tensor, torch.Tensor]], input_metadata: InputMetadata, ) -> torch.Tensor: # KV caches are fixed tensors, so we don't need to copy them. del kv_caches # Copy the input tensors to the input buffers. self.input_buffers["input_ids"].copy_(input_ids, non_blocking=True) self.input_buffers["positions"].copy_(positions, non_blocking=True) self.input_buffers["slot_mapping"].copy_(input_metadata.slot_mapping, non_blocking=True) self.input_buffers["context_lens"].copy_(input_metadata.context_lens, non_blocking=True) self.input_buffers["block_tables"].copy_(input_metadata.block_tables, non_blocking=True) # Run the graph. self.graph.replay() # Return the output tensor. return self.output_buffers["hidden_states"] def __call__(self, *args, **kwargs): return self.forward(*args, **kwargs) def _pad_to_max(x: List[int], max_len: int, pad: int) -> List[int]: assert len(x) <= max_len return x + [pad] * (max_len - len(x)) def _make_tensor_with_pad( x: List[List[int]], max_len: int, pad: int, dtype: torch.dtype, device: Union[str, torch.device] = "cuda", pin_memory: bool = False, ) -> torch.Tensor: padded_x = [_pad_to_max(x_i, max_len, pad) for x_i in x] return torch.tensor(padded_x, dtype=dtype, device=device, pin_memory=pin_memory and str(device) == "cpu") def _get_graph_batch_size(batch_size: int) -> int: if batch_size <= 2: return batch_size elif batch_size <= 4: return 4 else: return (batch_size + 7) // 8 * 8 def _async_h2d(data: list, dtype, pin_memory): t = torch.tensor(data, dtype=dtype, pin_memory=pin_memory) return t.to(device="cuda", non_blocking=True)