vllm/vllm/worker/model_runner.py
SangBin Cho 65bf2ac165
[Core][2/N] Model runner refactoring part 2. Combine prepare prefill / decode to a single API (#4681)
This PR combines prepare_prompt and prepare_decode into a single API. This PR also coelsce the attn metadata for prefill/decode to a single class and allow to slice them when running attn backend.

It also refactors subquery_start_loc which was not refactored in the previous PR
2024-05-15 14:00:10 +09:00

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import time
from typing import Dict, List, NamedTuple, Optional, Set, Tuple, Union
import numpy as np
import torch
import torch.nn as nn
from vllm.attention import AttentionMetadata, get_attn_backend
from vllm.config import (CacheConfig, DeviceConfig, LoadConfig, LoRAConfig,
ModelConfig, ParallelConfig, SchedulerConfig,
VisionLanguageConfig)
from vllm.distributed import broadcast_tensor_dict
from vllm.distributed.communication_op import graph_capture, graph_mode
from vllm.logger import init_logger
from vllm.lora.layers import LoRAMapping
from vllm.lora.request import LoRARequest
from vllm.lora.worker_manager import LRUCacheWorkerLoRAManager
from vllm.model_executor import SamplingMetadata
from vllm.model_executor.model_loader import get_model
from vllm.sampling_params import SamplingParams
from vllm.sequence import (MultiModalData, SamplerOutput, SequenceData,
SequenceGroupMetadata)
from vllm.utils import (CudaMemoryProfiler, get_kv_cache_torch_dtype, is_hip,
is_pin_memory_available, make_tensor_with_pad)
logger = init_logger(__name__)
_PAD_SLOT_ID = -1
LORA_WARMUP_RANK = 8
_BATCH_SIZE_ALIGNMENT = 8
# Capture graphs for token 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] + [
_BATCH_SIZE_ALIGNMENT * i for i in range(1, 33)
]
class ModelInput(NamedTuple):
input_tokens: torch.Tensor
input_positions: torch.Tensor
attn_metadata: Optional[AttentionMetadata]
seq_lens: List[int]
query_lens: List[int]
lora_mapping: Optional[LoRAMapping]
lora_requests: Set[LoRARequest]
multi_modal_input: Optional[torch.Tensor]
slot_mapping: torch.Tensor
num_prefill_tokens: int
num_decode_tokens: int
num_prefills: int
@classmethod
def empty(cls, device):
return ModelInput(
input_tokens=torch.empty(0, device=device),
input_positions=torch.empty(0, device=device),
attn_metadata=None,
seq_lens=[],
query_lens=[],
lora_mapping=None,
lora_requests=set(),
multi_modal_input=None,
slot_mapping=torch.empty(0, device=device),
num_prefill_tokens=0,
num_decode_tokens=0,
num_prefills=0,
)
class ModelRunner:
def __init__(
self,
model_config: ModelConfig,
parallel_config: ParallelConfig,
scheduler_config: SchedulerConfig,
device_config: DeviceConfig,
cache_config: CacheConfig,
load_config: LoadConfig,
lora_config: Optional[LoRAConfig],
kv_cache_dtype: Optional[str] = "auto",
is_driver_worker: bool = False,
vision_language_config: Optional[VisionLanguageConfig] = None,
):
self.model_config = model_config
self.parallel_config = parallel_config
self.scheduler_config = scheduler_config
self.device_config = device_config
self.cache_config = cache_config
self.lora_config = lora_config
self.load_config = load_config
self.is_driver_worker = is_driver_worker
self.vision_language_config = vision_language_config
self.device = self.device_config.device
self.pin_memory = is_pin_memory_available()
self.kv_cache_dtype = kv_cache_dtype
self.sliding_window = model_config.get_sliding_window()
self.block_size = cache_config.block_size
self.max_seq_len_to_capture = self.model_config.max_seq_len_to_capture
self.graph_runners: Dict[int, CUDAGraphRunner] = {}
self.graph_memory_pool: Optional[Tuple[
int, int]] = None # Set during graph capture.
# When using CUDA graph, the input block tables must be padded to
# max_seq_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 = np.zeros(
(max(_BATCH_SIZES_TO_CAPTURE), self.get_max_block_per_batch()),
dtype=np.int32)
self.attn_backend = get_attn_backend(
self.model_config.get_num_attention_heads(self.parallel_config),
self.model_config.get_head_size(),
self.model_config.get_num_kv_heads(self.parallel_config),
self.model_config.get_sliding_window(),
self.model_config.dtype,
self.kv_cache_dtype,
self.block_size,
)
# Lazy initialization
self.model: nn.Module # Set after load_model
# Set if the backend is flashinfer.
self.flashinfer_workspace_buffer: torch.Tensor
# Set after load_model.
self.lora_manager: Optional[LRUCacheWorkerLoRAManager] = None
def load_model(self) -> None:
with CudaMemoryProfiler() as m:
self.model = get_model(
model_config=self.model_config,
device_config=self.device_config,
load_config=self.load_config,
lora_config=self.lora_config,
vision_language_config=self.vision_language_config,
parallel_config=self.parallel_config,
scheduler_config=self.scheduler_config,
cache_config=self.cache_config,
)
self.model_memory_usage = m.consumed_memory
logger.info("Loading model weights took %.4f GB",
self.model_memory_usage / float(2**30))
if self.lora_config:
assert hasattr(self.model, "supported_lora_modules"
) and self.model.supported_lora_modules, (
"Model does not support LoRA")
assert hasattr(
self.model,
"embedding_modules"), "Model does not have embedding_modules"
assert hasattr(self.model, "embedding_padding_modules"
), "Model does not have embedding_padding_modules"
self.lora_manager = LRUCacheWorkerLoRAManager(
self.scheduler_config.max_num_seqs,
self.scheduler_config.max_num_batched_tokens, self.vocab_size,
self.lora_config, self.device, self.model.embedding_modules,
self.model.embedding_padding_modules)
self.model = self.lora_manager.create_lora_manager(self.model)
if self.kv_cache_dtype == "fp8" and is_hip():
# Currently scaled KV cache is only enabled on ROCm
if self.model_config.quantization_param_path is not None:
if callable(getattr(self.model, "load_kv_cache_scales", None)):
self.model.load_kv_cache_scales(
self.model_config.quantization_param_path)
else:
raise RuntimeError(
"Using FP8 KV cache and scaling factors provided but "
"model %s does not support loading scaling factors.",
self.model.__class__)
else:
logger.warning(
"Using FP8 KV cache but no scaling factors "
"provided. Defaulting to scaling factors of 1.0. "
"This may lead to less accurate results!")
elif self.model_config.quantization_param_path is not None:
logger.warning("KV cache scaling factors provided, "
"but the KV cache data type is not FP8. "
"KV cache scaling factors will not be used.")
def get_max_block_per_batch(self) -> int:
block_size = self.block_size
return (self.max_seq_len_to_capture + block_size - 1) // block_size
def _prepare_model_input(
self,
seq_group_metadata_list: List[SequenceGroupMetadata],
) -> ModelInput:
"""Prepare the model input based on a given sequence group.
The API assumes seq_group_metadata_list is sorted by prefill -> decode.
The result tensors and data structure also batches input in prefill
-> decode order. For example,
- input_tokens[:num_prefill_tokens] contains prefill tokens.
- input_tokens[num_prefill_tokens:] contains decode tokens.
If cuda graph is required, this API automatically pads inputs.
"""
input_tokens: List[int] = []
input_positions: List[int] = []
slot_mapping: List[int] = []
lora_index_mapping: List[int] = []
lora_prompt_mapping: List[int] = []
lora_requests: Set[LoRARequest] = set()
seq_lens: List[int] = []
prefill_seq_lens: List[int] = []
decode_seq_lens: List[int] = []
context_lens: List[int] = []
query_lens: List[int] = []
block_tables: List[List[int]] = []
multi_modal_input_list: List[torch.Tensor] = []
decode_only = True
num_prefills = 0
num_prefill_tokens = 0
num_decode_tokens = 0
# The following fields are only for flashinfer
# Please follow https://docs.flashinfer.ai/tutorials/kv_layout.html#page-layout
# for the precise definition of the following fields.
# An example:
# request 1, page indices [0, 5, 8]
# request 2, page indices [1, 6, 7]
# request 3, page indices [3, 4]
# paged_kv_indices is a concatenation of page indices of all requests:
# [0, 5, 8, 1, 6, 7, 3, 4]
# paged_kv_indptr is used to index into paged_kv_indices:
# [0, 3, 6, 8]
paged_kv_indices: List[int] = []
# 0 at the beginning of paged_kv_indptr indicates the start of the
# first requests page indices in the paged_kv_indices list.
paged_kv_indptr: List[int] = [0]
# paged_kv_last_page_len is the length of the last page of each request
paged_kv_last_page_len: List[int] = []
if len(seq_group_metadata_list) == 0:
return ModelInput.empty(self.device)
for seq_group_metadata in seq_group_metadata_list:
seq_ids = list(seq_group_metadata.seq_data.keys())
is_prompt = seq_group_metadata.is_prompt
for seq_id in seq_ids:
computed_block_nums = seq_group_metadata.computed_block_nums
if (self.scheduler_config is not None
and self.scheduler_config.chunked_prefill_enabled
and not (computed_block_nums is None
or computed_block_nums == [])):
raise RuntimeError(
"chunked prefill cannot be used with prefix caching "
"now.")
seq_data = seq_group_metadata.seq_data[seq_id]
if is_prompt:
context_len = seq_data.get_num_computed_tokens()
else:
# get_num_computed_tokens is incorrect for spec decoding.
# So, we should have a special logic here.
# TODO(sang): Fix it.
context_len = seq_data.get_len() - 1
seq_len = min(
seq_data.get_len(),
context_len + seq_group_metadata.token_chunk_size)
if is_prompt:
tokens = seq_data.get_token_ids()[context_len:seq_len]
else:
# Optimization. get_token_ids requires the entire copy of
# tokens.
tokens = [seq_data.get_last_token_id()]
# Prefix cache was hit.
# Prefix is not supported with sliding_window
prefix_cache_hit = (computed_block_nums is not None
and len(computed_block_nums) > 0
and self.sliding_window is None
and is_prompt)
# TODO(sang): Combine chunked prefill and prefix caching by
# only allowing multiple of block_size chunk size.
# NOTE: This only works for oooooooxxx style attention.
if prefix_cache_hit:
assert computed_block_nums is not None
context_len = len(computed_block_nums) * self.block_size
tokens = tokens[context_len:]
if self.attn_backend.get_name() == "flash-attn":
# NOTE(woosuk): For flash-attn, the block table should
# include the entries for the incoming prefill tokens.
# TODO(woosuk): This is a temporary fix. We should
# provide a unified interface for different backends.
block_table = seq_group_metadata.block_tables[seq_id]
else:
block_table = computed_block_nums
elif (self.scheduler_config.chunked_prefill_enabled
or not is_prompt):
if seq_group_metadata.block_tables is not None:
# chunked prefill or decode
block_table = seq_group_metadata.block_tables[seq_id]
if self.sliding_window is not None:
# chunked prefill doesn't support sliding window.
assert (not self.scheduler_config.
chunked_prefill_enabled)
sliding_window_blocks = (self.sliding_window //
self.block_size)
block_table = block_table[-sliding_window_blocks:]
if self.attn_backend.get_name() == "flashinfer":
paged_kv_indices.extend(block_table)
paged_kv_indptr.append(paged_kv_indptr[-1] +
len(block_table))
last_page_len = seq_data.get_len(
) % self.block_size
if last_page_len == 0:
last_page_len = self.block_size
paged_kv_last_page_len.append(last_page_len)
else:
# Only happens when memory profiling runs.
block_table = []
else:
# Prefill without chunked prefill or memory profiling.
block_table = []
block_tables.append(block_table)
# TODO(sang): This is a hack to make sliding window work with
# paged attn. We can remove it if we make paged attn kernel
# to properly handle slinding window attn.
if (self.sliding_window is not None and not is_prompt):
seq_len = min(seq_len, self.sliding_window)
context_len = seq_len - 1
seq_lens.append(seq_len)
context_lens.append(context_len)
query_len = seq_len - context_len
query_lens.append(query_len)
input_tokens.extend(tokens)
input_positions.extend(list(range(context_len, seq_len)))
lora_id = seq_group_metadata.lora_int_id
if is_prompt:
assert len(seq_ids) == 1
num_prefills += 1
num_prefill_tokens += len(tokens)
decode_only = False
prefill_seq_lens.append(seq_len)
else:
assert query_len == 1, (
"seq_len: {}, context_len: {}, query_len: {}".format(
seq_len, context_len, query_len))
num_decode_tokens += query_len
decode_seq_lens.append(seq_len)
if lora_id > 0:
lora_requests.add(seq_group_metadata.lora_request)
lora_index_mapping += [lora_id] * (seq_len - context_len)
lora_prompt_mapping.extend(
[lora_id] *
(seq_len -
context_len if seq_group_metadata.sampling_params
and seq_group_metadata.sampling_params.prompt_logprobs
else 1))
if seq_group_metadata.multi_modal_data:
multi_modal_input_list.append(
seq_group_metadata.multi_modal_data.data)
if _is_block_tables_empty(seq_group_metadata.block_tables):
# During memory profiling, the block tables are not
# initialized yet. In this case, we just use a dummy
# slot mapping.
# In embeddings, the block tables are {seq_id: None}.
slot_mapping.extend([_PAD_SLOT_ID] * seq_len)
continue
# Compute the slot mapping.
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, seq_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:
if is_prompt:
assert context_len == 0, (
"Prefix caching is currently not supported with "
"sliding window attention")
# It is an optimization. When it is decoding, it is always
# 0. When prefill, we use it to not write slots to kv cache
# to save memory.
start_idx = max(0, query_len - self.sliding_window)
for i in range(context_len, seq_len):
if i < start_idx:
slot_mapping.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.append(slot)
batch_size = len(input_tokens)
max_query_len = max(query_lens)
max_prefill_seq_len = max(prefill_seq_lens, default=0)
max_decode_seq_len = max(decode_seq_lens, default=0)
# If cuda graph can be used, pad tensors accordingly.
# See `capture_model` API for more details.
# vLLM uses cuda graph only for decoding requests.
use_captured_graph = (
decode_only and not self.model_config.enforce_eager
and batch_size <= _BATCH_SIZES_TO_CAPTURE[-1]
and max_decode_seq_len <= self.max_seq_len_to_capture)
if use_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(0)
input_positions.append(0)
slot_mapping.append(_PAD_SLOT_ID)
seq_lens.append(1)
block_tables.append([])
lora_index_mapping.append(0)
batch_size = graph_batch_size
num_decode_tokens = batch_size
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=self.device)
else:
max_block_table_len = max(
len(block_table) for block_table in block_tables)
block_tables = make_tensor_with_pad(
block_tables,
max_len=max_block_table_len,
pad=0,
dtype=torch.int,
device=self.device,
)
assert max_query_len > 0, ("query_lens: {}".format(query_lens))
context_lens_tensor = torch.tensor(context_lens,
dtype=torch.int,
device=self.device)
if multi_modal_input_list:
assert self.vision_language_config, (
"Multi-modal inputs are only supported by "
"vision language models.")
multi_modal_input = torch.cat(multi_modal_input_list,
dim=0).to(self.device)
else:
multi_modal_input = None
seq_lens_tensor = torch.tensor(seq_lens,
dtype=torch.int,
device=self.device)
query_lens_tensor = torch.tensor(query_lens,
dtype=torch.long,
device=self.device)
query_start_loc = torch.zeros(query_lens_tensor.shape[0] + 1,
dtype=torch.int32,
device=self.device)
seq_lens_tensor = torch.tensor(seq_lens,
dtype=torch.int,
device=self.device)
seq_start_loc = torch.zeros(seq_lens_tensor.shape[0] + 1,
dtype=torch.int32,
device=self.device)
torch.cumsum(query_lens_tensor,
dim=0,
dtype=query_start_loc.dtype,
out=query_start_loc[1:])
torch.cumsum(seq_lens_tensor,
dim=0,
dtype=seq_start_loc.dtype,
out=seq_start_loc[1:])
input_tokens_tensor = torch.tensor(input_tokens,
dtype=torch.long,
device=self.device)
input_positions_tensor = torch.tensor(input_positions,
dtype=torch.long,
device=self.device)
slot_mapping_tensor = torch.tensor(slot_mapping,
dtype=torch.long,
device=self.device)
if self.attn_backend.get_name() == "flashinfer":
if not hasattr(self, "flashinfer_workspace_buffer"):
# Allocate 16MB workspace buffer
# Follow the example of flashinfer: https://docs.flashinfer.ai/api/python/decode.html
self.flashinfer_workspace_buffer = torch.empty(
16 * 1024 * 1024, dtype=torch.uint8, device=self.device)
paged_kv_indptr_tensor = torch.tensor(paged_kv_indptr,
dtype=torch.int,
device=self.device)
paged_kv_indices_tensor = torch.tensor(paged_kv_indices,
dtype=torch.int,
device=self.device)
paged_kv_last_page_len_tensor = torch.tensor(
paged_kv_last_page_len, dtype=torch.int, device=self.device)
kv_cache_dtype = get_kv_cache_torch_dtype(self.kv_cache_dtype,
self.model_config.dtype)
attn_metadata = self.attn_backend.make_metadata(
num_prefills=num_prefills,
slot_mapping=slot_mapping_tensor,
num_prefill_tokens=num_prefill_tokens,
num_decode_tokens=num_decode_tokens,
use_cuda_graph=False,
max_prefill_seq_len=max_prefill_seq_len,
block_tables=block_tables,
workspace_buffer=self.flashinfer_workspace_buffer,
paged_kv_indptr=paged_kv_indptr_tensor,
paged_kv_indices=paged_kv_indices_tensor,
paged_kv_last_page_len=paged_kv_last_page_len_tensor,
num_qo_heads=self.model_config.get_num_attention_heads(
self.parallel_config),
num_kv_heads=self.model_config.get_num_kv_heads(
self.parallel_config),
head_dim=self.model_config.get_head_size(),
page_size=16,
seq_start_loc=seq_start_loc,
data_type=kv_cache_dtype)
else:
attn_metadata = self.attn_backend.make_metadata(
num_prefills=num_prefills,
slot_mapping=slot_mapping_tensor,
num_prefill_tokens=num_prefill_tokens,
num_decode_tokens=num_decode_tokens,
seq_lens=seq_lens,
seq_lens_tensor=seq_lens_tensor,
max_query_len=max_query_len,
max_prefill_seq_len=max_prefill_seq_len,
max_decode_seq_len=max_decode_seq_len,
query_start_loc=query_start_loc,
seq_start_loc=seq_start_loc,
context_lens_tensor=context_lens_tensor,
block_tables=block_tables,
use_cuda_graph=use_captured_graph,
)
if self.lora_config:
lora_mapping = LoRAMapping(
lora_index_mapping,
lora_prompt_mapping,
)
else:
lora_mapping = None
return ModelInput(
input_tokens=input_tokens_tensor,
input_positions=input_positions_tensor,
attn_metadata=attn_metadata,
seq_lens=seq_lens,
query_lens=query_lens,
lora_mapping=lora_mapping,
lora_requests=lora_requests,
multi_modal_input=multi_modal_input,
slot_mapping=slot_mapping_tensor,
num_prefill_tokens=num_prefill_tokens,
num_decode_tokens=num_decode_tokens,
num_prefills=num_prefills,
)
def prepare_input_tensors(
self,
seq_group_metadata_list: List[SequenceGroupMetadata],
) -> Tuple[torch.Tensor, torch.Tensor, AttentionMetadata, SamplingMetadata,
Set[LoRARequest], LoRAMapping, torch.Tensor]:
if self.is_driver_worker:
# Prepare input tensors.
(
input_tokens,
input_positions,
attn_metadata,
seq_lens,
query_lens,
lora_mapping,
lora_requests,
multi_modal_input,
slot_mapping,
num_prefill_tokens,
num_decode_tokens,
num_prefills,
) = self._prepare_model_input(seq_group_metadata_list)
sampling_metadata = SamplingMetadata.prepare(
seq_group_metadata_list, seq_lens, query_lens, self.device,
self.pin_memory)
metadata_dict = {
"input_tokens": input_tokens,
"input_positions": input_positions,
"selected_token_indices":
sampling_metadata.selected_token_indices,
"lora_requests": lora_requests,
"lora_mapping": lora_mapping,
"multi_modal_input": multi_modal_input,
"num_prefill_tokens": num_prefill_tokens,
"num_decode_tokens": num_decode_tokens,
"slot_mapping": slot_mapping,
"num_prefills": num_prefills,
}
if attn_metadata:
metadata_dict.update(attn_metadata.asdict_zerocopy())
broadcast_tensor_dict(metadata_dict, src=0)
else:
metadata_dict = broadcast_tensor_dict(src=0)
input_tokens = metadata_dict.pop("input_tokens")
input_positions = metadata_dict.pop("input_positions")
selected_token_indices = metadata_dict.pop(
"selected_token_indices")
lora_mapping = metadata_dict.pop("lora_mapping")
lora_requests = metadata_dict.pop("lora_requests")
multi_modal_input = metadata_dict.pop("multi_modal_input")
if metadata_dict:
attn_metadata = self.attn_backend.make_metadata(
**metadata_dict)
else:
attn_metadata = None
sampling_metadata = SamplingMetadata(
seq_groups=None,
selected_token_indices=selected_token_indices,
categorized_sample_indices=None,
num_prompts=0,
)
return (input_tokens, input_positions, attn_metadata,
sampling_metadata, lora_requests, lora_mapping,
multi_modal_input)
@torch.inference_mode()
def execute_model(
self,
seq_group_metadata_list: List[SequenceGroupMetadata],
kv_caches: List[torch.Tensor],
) -> Optional[SamplerOutput]:
(input_tokens, input_positions, attn_metadata, sampling_metadata,
lora_requests, lora_mapping, multi_modal_input
) = self.prepare_input_tensors(seq_group_metadata_list)
if self.lora_config:
self.set_active_loras(lora_requests, lora_mapping)
# Currently cuda graph is only supported by the decode phase.
prefill_meta = attn_metadata.prefill_metadata
decode_meta = attn_metadata.decode_metadata
if prefill_meta is None and decode_meta.use_cuda_graph:
graph_batch_size = input_tokens.shape[0]
model_executable = self.graph_runners[graph_batch_size]
else:
model_executable = self.model
execute_model_kwargs = {
"input_ids": input_tokens,
"positions": input_positions,
"kv_caches": kv_caches,
"attn_metadata": attn_metadata,
}
if self.vision_language_config:
execute_model_kwargs.update({"image_input": multi_modal_input})
hidden_states = model_executable(**execute_model_kwargs)
# Compute the logits.
logits = self.model.compute_logits(hidden_states, sampling_metadata)
# Only perform sampling in the driver worker.
if not self.is_driver_worker:
return None
# Sample the next token.
output = self.model.sample(
logits=logits,
sampling_metadata=sampling_metadata,
)
return output
@torch.inference_mode()
def profile_run(self) -> None:
# Enable top-k sampling to reflect the accurate memory usage.
sampling_params = SamplingParams(top_p=0.99, top_k=self.vocab_size - 1)
max_num_batched_tokens = self.scheduler_config.max_num_batched_tokens
max_num_seqs = self.scheduler_config.max_num_seqs
# This represents the maximum number of different requests
# that will have unique loras, an therefore the max amount of memory
# consumption create dummy lora request copies from the lora request
# passed in, which contains a lora from the lora warmup path.
dummy_lora_requests = []
dummy_lora_requests_per_seq = []
if self.lora_config:
assert self.lora_manager is not None
with self.lora_manager.dummy_lora_cache():
for idx in range(self.lora_config.max_loras):
lora_id = idx + 1
dummy_lora_request = LoRARequest(
lora_name=f"warmup_{lora_id}",
lora_int_id=lora_id,
lora_local_path="/not/a/real/path",
)
self.lora_manager.add_dummy_lora(dummy_lora_request,
rank=LORA_WARMUP_RANK)
dummy_lora_requests.append(dummy_lora_request)
dummy_lora_requests_per_seq = [
dummy_lora_requests[idx % len(dummy_lora_requests)]
for idx in range(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] = []
# Additional GPU memory may be needed for vision encoding, which needs
# to be accounted for when calculating the GPU blocks for
# vLLM blocker manager.
# To exercise the worst scenario for GPU memory consumption,
# the number of seqs (batch_size) is chosen to maximize the number
# of images processed.
if self.vision_language_config:
max_num_seqs = min(
max_num_seqs,
int(max_num_batched_tokens /
self.vision_language_config.image_feature_size))
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, fake_multi_modal_input = _prepare_fake_inputs(
seq_len, self.vision_language_config)
seq = SequenceGroupMetadata(
request_id=str(group_id),
is_prompt=True,
seq_data={group_id: seq_data},
sampling_params=sampling_params,
block_tables=None,
lora_request=dummy_lora_requests_per_seq[group_id]
if dummy_lora_requests_per_seq else None,
multi_modal_data=fake_multi_modal_input,
)
seqs.append(seq)
# Run the model with the dummy inputs.
num_layers = self.model_config.get_num_layers(self.parallel_config)
kv_caches = [None] * num_layers
self.execute_model(seqs, kv_caches)
torch.cuda.synchronize()
return
def remove_all_loras(self):
if not self.lora_manager:
raise RuntimeError("LoRA is not enabled.")
self.lora_manager.remove_all_loras()
def set_active_loras(self, lora_requests: Set[LoRARequest],
lora_mapping: LoRAMapping) -> None:
if not self.lora_manager:
raise RuntimeError("LoRA is not enabled.")
self.lora_manager.set_active_loras(lora_requests, lora_mapping)
def add_lora(self, lora_request: LoRARequest) -> bool:
if not self.lora_manager:
raise RuntimeError("LoRA is not enabled.")
return self.lora_manager.add_lora(lora_request)
def remove_lora(self, lora_id: int) -> bool:
if not self.lora_manager:
raise RuntimeError("LoRA is not enabled.")
return self.lora_manager.remove_lora(lora_id)
def list_loras(self) -> Set[int]:
if not self.lora_manager:
raise RuntimeError("LoRA is not enabled.")
return self.lora_manager.list_loras()
@torch.inference_mode()
def capture_model(self, kv_caches: List[torch.Tensor]) -> None:
"""Cuda graph capture a model.
Note that CUDA graph's performance gain is negligible if number
of batched tokens are larger than 200. And since CUDA graph
requires fixed sized tensors, supporting large/variable batch
size requires high GPU memory overhead. Thus, vLLM only captures
decoding requests. Mixed batch (chunked prefill + decoding) or
prefill requests are not captured.
Since it is used for decoding-only, it assumes there's only 1 token
per sequence in the batch.
"""
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, dtype=torch.long).cuda()
input_positions = torch.zeros(max_batch_size, dtype=torch.long).cuda()
slot_mapping = torch.empty(max_batch_size, dtype=torch.long).cuda()
slot_mapping.fill_(_PAD_SLOT_ID)
seq_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
]
with graph_capture():
# 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 attn_metadata.
attn_metadata = self.attn_backend.make_metadata(
num_prefills=0,
num_prefill_tokens=0,
num_decode_tokens=batch_size,
slot_mapping=slot_mapping[:batch_size],
seq_lens=None,
seq_lens_tensor=seq_lens[:batch_size],
max_query_len=None,
max_prefill_seq_len=0,
max_decode_seq_len=self.max_seq_len_to_capture,
query_start_loc=None,
seq_start_loc=None,
context_lens_tensor=None,
block_tables=block_tables[:batch_size],
use_cuda_graph=True,
)
if self.lora_config:
lora_mapping = LoRAMapping(
[0] * batch_size,
[0] * batch_size,
)
self.set_active_loras(set(), lora_mapping)
graph_runner = CUDAGraphRunner(self.model)
graph_runner.capture(
input_tokens[:batch_size],
input_positions[:batch_size],
kv_caches,
attn_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("Graph capturing finished in %.0f secs.", elapsed_time)
def __del__(self) -> None:
# Delete the CUDA graphs before deleting the pynccl communicator.
# NOTE(woosuk): This is necessary because otherwise deadlocks can
# happen.
# FIXME(woosuk): This is a bit hacky. Find a more robust solution.
# TODO(youkaichao): when we get enough user feedback that pynccl is
# more stable than cupy, we can remove this, e.g. in v0.4.1.
self.graph_runners.clear()
self.pynccl_backend = None
@property
def vocab_size(self) -> int:
return self.model_config.get_vocab_size()
class CUDAGraphRunner:
def __init__(self, model: nn.Module):
self.model = model
self.input_buffers: Dict[str, torch.Tensor] = {}
self.output_buffers: Dict[str, torch.Tensor] = {}
self._graph: Optional[torch.cuda.CUDAGraph] = None
@property
def graph(self):
assert self._graph is not None
return self._graph
def capture(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
memory_pool,
**kwargs,
) -> 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).
with graph_mode():
self.model(
input_ids,
positions,
kv_caches,
attn_metadata,
**kwargs,
)
torch.cuda.synchronize()
# Capture the graph.
# NOTE(woosuk): Python 3.8 does not support multi-line with statements.
# https://stackoverflow.com/questions/31039022/python-multi-line-with-statement
self._graph = torch.cuda.CUDAGraph()
with torch.cuda.graph(self._graph, pool=memory_pool): # noqa: SIM117
with graph_mode():
hidden_states = self.model(
input_ids,
positions,
kv_caches,
attn_metadata,
**kwargs,
)
torch.cuda.synchronize()
# Save the input and output buffers.
self.input_buffers = {
"input_ids": input_ids,
"positions": positions,
"kv_caches": kv_caches,
"slot_mapping": attn_metadata.slot_mapping,
"seq_lens_tensor": attn_metadata.decode_metadata.seq_lens_tensor,
"block_tables": attn_metadata.decode_metadata.block_tables,
}
self.output_buffers = {"hidden_states": hidden_states}
return
def forward(
self,
input_ids: torch.Tensor,
positions: torch.Tensor,
kv_caches: List[torch.Tensor],
attn_metadata: AttentionMetadata,
**kwargs,
) -> 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_(attn_metadata.slot_mapping,
non_blocking=True)
self.input_buffers["seq_lens_tensor"].copy_(
attn_metadata.decode_metadata.seq_lens_tensor, non_blocking=True)
self.input_buffers["block_tables"].copy_(
attn_metadata.decode_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 _get_graph_batch_size(batch_size: int) -> int:
"""Returns the padded batch size given actual batch size.
Batch sizes are 1, 2, 4, _BATCH_SIZE_ALIGNMENT,
2*_BATCH_SIZE_ALIGNMENT, 3*_BATCH_SIZE_ALIGNMENT...
"""
if batch_size <= 2:
return batch_size
elif batch_size <= 4:
return 4
else:
return ((batch_size + _BATCH_SIZE_ALIGNMENT - 1) //
_BATCH_SIZE_ALIGNMENT * _BATCH_SIZE_ALIGNMENT)
def _prepare_fake_inputs(
seq_len: int, vision_language_config: Optional[VisionLanguageConfig]):
"""Prepare fake inputs for profile run."""
if vision_language_config:
prompt_tokens = [
vision_language_config.image_token_id
] * vision_language_config.image_feature_size + [0] * (
seq_len - vision_language_config.image_feature_size)
fake_image_input = MultiModalData(
type=MultiModalData.Type.IMAGE,
data=torch.zeros(vision_language_config.image_input_shape,
dtype=torch.float16))
else:
prompt_tokens = [0] * seq_len
fake_image_input = None
return SequenceData(prompt_tokens), fake_image_input
def _is_block_tables_empty(block_tables: Union[None, Dict]):
"""
Check if block_tables is None or a dictionary with all None values.
"""
if block_tables is None:
return True
if isinstance(block_tables, dict) and all(
value is None for value in block_tables.values()):
return True
return False