Files
vllm-omni/vllm_omni/worker/gpu_ar_model_runner.py
T
tzhouam 53b86439fc Refactor ARModelRunner to streamline hidden state handling
- Removed unnecessary imports of numpy and torch within the request scheduling logic.
- Simplified the handling of auxiliary hidden states by initializing it to None when not present.
- Optimized CPU tensor conversion for text hidden states to improve performance.
2025-10-22 17:16:15 +08:00

579 lines
27 KiB
Python

"""AR GPU Model Runner for vLLM-omni.
Exposes per-request hidden representations via ModelRunnerOutput.pooler_output
and also outputs sampled tokens.
"""
from __future__ import annotations
from typing import Optional, Union, Any, List
import numpy as np
import torch
from vllm import envs
from vllm.v1.worker.gpu_model_runner import (
EMPTY_MODEL_RUNNER_OUTPUT,
IntermediateTensors,
get_pp_group,
get_tp_group,
has_kv_transfer_group,
set_forward_context,
)
from vllm.v1.core.sched.output import SchedulerOutput
from vllm.multimodal.inputs import MultiModalKwargs
from vllm.v1.attention.backends.utils import CommonAttentionMetadata
from vllm.v1.spec_decode.eagle import EagleProposer
from vllm_omni.engine import PromptEmbedsPayload, AdditionalInformationPayload
from vllm_omni.outputs import OmniModelRunnerOutput
from vllm_omni.worker.gpu_model_runner import OmniGPUModelRunner
class ARModelRunner(OmniGPUModelRunner):
"""Autoregressive GPU model runner that returns hidden states per request.
This runner follows the same preparation and forward path as GPUModelRunner
(inputs assembly, multi-modal handling, TP/PP/DP integration, CUDA graphs),
and additionally performs lightweight sampling so that sampled tokens are
available in outputs. Hidden representations are taken at the same indices
that GPUModelRunner would use for sampling/logits (i.e. `logits_indices`).
"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.input_ids = torch.zeros(self.max_num_tokens,
dtype=torch.int64,
device=self.device)
@torch.inference_mode()
def execute_model(
self,
scheduler_output: "SchedulerOutput",
intermediate_tensors: Optional[IntermediateTensors] = None,
) -> Union[OmniModelRunnerOutput, IntermediateTensors]:
# Update internal state with the new schedule
self._update_states(scheduler_output)
# Decode per-request prompt_embeds / additional_hidden_states payloads (if present) into CPU tensors
try:
new_reqs = getattr(scheduler_output, "scheduled_new_reqs", [])
if new_reqs:
for nr in new_reqs:
req_id = getattr(nr, "req_id", None) or getattr(nr, "request_id", None)
if req_id is None:
continue
# prompt_embeds
payload_pe = getattr(nr, "prompt_embeds", None)
if payload_pe is not None:
if isinstance(payload_pe, torch.Tensor):
pe_cpu = payload_pe.detach().to("cpu").contiguous()
elif isinstance(payload_pe, PromptEmbedsPayload):
dt = np.dtype(getattr(payload_pe, "dtype", "float32"))
arr = np.frombuffer(payload_pe.data, dtype=dt)
arr = arr.reshape(payload_pe.shape)
pe_cpu = torch.from_numpy(arr)
else:
pe_cpu = None
if pe_cpu is not None and req_id in self.requests:
setattr(self.requests[req_id], "prompt_embeds_cpu", pe_cpu)
# additional_information
payload_info = getattr(nr, "additional_information", None)
if payload_info is not None:
info_dict = {}
if isinstance(payload_info, dict):
# Already decoded
info_dict = payload_info
elif isinstance(payload_info, AdditionalInformationPayload):
for k, entry in payload_info.entries.items():
if entry.tensor_data is not None:
dt = np.dtype(getattr(entry, "tensor_dtype", "float32"))
arr = np.frombuffer(entry.tensor_data, dtype=dt)
arr = arr.reshape(entry.tensor_shape)
info_dict[k] = torch.from_numpy(arr)
else:
info_dict[k] = entry.list_data
if info_dict and req_id in self.requests:
setattr(self.requests[req_id], "additional_information_cpu", info_dict)
except Exception:
pass
# If there's no work to do, either return empty output or kv-only path
if not scheduler_output.total_num_scheduled_tokens:
if not has_kv_transfer_group():
return EMPTY_MODEL_RUNNER_OUTPUT
return self.kv_connector_no_forward(scheduler_output,
self.vllm_config)
# Prepare decoder inputs and attention metadata
(attn_metadata, attention_cuda_graphs, logits_indices,
spec_decode_metadata, num_scheduled_tokens_np,
spec_decode_common_attn_metadata) = self._prepare_inputs(
scheduler_output)
# Determine number of input tokens for this iteration
num_scheduled_tokens = scheduler_output.total_num_scheduled_tokens
if (self.use_cuda_graph
and num_scheduled_tokens <= self.cudagraph_batch_sizes[-1]):
num_input_tokens = self.vllm_config.pad_for_cudagraph(
num_scheduled_tokens)
else:
tp_size = self.vllm_config.parallel_config.tensor_parallel_size
if (self.compilation_config.pass_config.enable_sequence_parallelism
and tp_size > 1):
from vllm.utils import round_up # lazy local import
num_input_tokens = round_up(num_scheduled_tokens, tp_size)
else:
num_input_tokens = num_scheduled_tokens
# DP padding
num_pad, num_tokens_across_dp = self.get_dp_padding(num_input_tokens)
num_input_tokens += num_pad
# Multimodal handling (encode and gather embeddings if needed)
if self.is_multimodal_model:
self._execute_mm_encoder(scheduler_output)
mm_embeds = self._gather_mm_embeddings(scheduler_output)
else:
mm_embeds = []
# Always assemble inputs_embeds on first PP rank; overlay per-request prompt_embeds and collect additional_hidden_states for prefill only
if get_pp_group().is_first_rank:
inputs_embeds_scheduled = self.model.get_input_embeddings(
input_ids=self.input_ids[:num_scheduled_tokens],
multimodal_embeddings=(mm_embeds or None)
if self.is_multimodal_model else None,
)
# Copy into persistent buffer to enable CUDA Graph capture
self.inputs_embeds[:num_scheduled_tokens].copy_(
inputs_embeds_scheduled)
# Reset per-step additional information collector
if hasattr(self, "_forward_additional_information"):
self._forward_additional_information = None
# Overlay custom prompt_embeds per request for the prompt portion; collect additional_information (tensor/list) for prefill portion only
for req_index, req_id in enumerate(self.input_batch.req_ids):
req_state = self.requests[req_id]
pe_cpu = getattr(req_state, "prompt_embeds_cpu", None)
addi_cpu = getattr(req_state, "additional_information_cpu", None)
num_computed_tokens = int(
self.input_batch.num_computed_tokens_cpu[req_index])
prompt_len = len(req_state.prompt_token_ids)
prompt_remaining = max(0, prompt_len - num_computed_tokens)
sched_tokens = int(num_scheduled_tokens_np[req_index])
overlay_len = min(sched_tokens, prompt_remaining)
if overlay_len <= 0:
continue
if pe_cpu is not None:
src = pe_cpu[num_computed_tokens:
num_computed_tokens + overlay_len].to(
dtype=self.dtype,
device=self.device,
non_blocking=True)
start_offset = int(self.query_start_loc_cpu[req_index])
self.inputs_embeds[start_offset:start_offset + overlay_len] \
.copy_(src)
# For additional_information: handle arbitrary keys
if addi_cpu is not None and isinstance(addi_cpu, dict):
# Lazy init collector dict
if not hasattr(self, "_forward_additional_information") or \
self._forward_additional_information is None:
self._forward_additional_information = {}
# Process tensors (slice by scheduled prompt range) and lists (append per-request)
for k, v in addi_cpu.items():
if isinstance(v, torch.Tensor):
# Slice along token dimension for prefill part
try:
seg = v[num_computed_tokens:
num_computed_tokens + overlay_len].to(
dtype=self.dtype,
device=self.device,
non_blocking=True)
except Exception:
# Fallback: move whole tensor if slicing fails
seg = v.to(dtype=self.dtype,
device=self.device,
non_blocking=True)
prev_val = self._forward_additional_information.get(k)
self._forward_additional_information[k] = (
torch.cat([prev_val, seg], dim=0)
if isinstance(prev_val, torch.Tensor) else seg.clone())
elif isinstance(v, list):
prev_val = self._forward_additional_information.get(k)
if prev_val is None:
self._forward_additional_information[k] = [v]
elif isinstance(prev_val, list):
self._forward_additional_information[k].append(v)
else:
# Mixed types: wrap existing into list
self._forward_additional_information[k] = [prev_val, v]
input_ids = self.input_ids[:num_input_tokens] # preserved for APIs
inputs_embeds = self.inputs_embeds[:num_input_tokens]
model_mm_kwargs = (self._extract_mm_kwargs(scheduler_output)
if self.is_multimodal_model else {})
else:
input_ids = self.input_ids[:num_input_tokens]
inputs_embeds = None
model_mm_kwargs = {}
# Positions/mRoPE
if self.uses_mrope:
positions = self.mrope_positions[:, :num_input_tokens]
else:
positions = self.positions[:num_input_tokens]
# Handle pipeline-parallel intermediate tensors
if get_pp_group().is_first_rank:
intermediate_tensors = None
else:
intermediate_tensors = self.sync_and_slice_intermediate_tensors(
num_input_tokens, intermediate_tensors, True)
# Some attention backends only support CUDA Graphs in pure decode.
skip_cuda_graphs = self.full_cuda_graph and not attention_cuda_graphs
# Forward pass
with set_forward_context(
attn_metadata,
self.vllm_config,
num_tokens=num_input_tokens,
num_tokens_across_dp=num_tokens_across_dp,
skip_cuda_graphs=skip_cuda_graphs,
), self.maybe_get_kv_connector_output(
scheduler_output) as kv_connector_output:
model_kwargs_extra = {}
# Only pass additional_information for the prefill part
if hasattr(self, "_forward_additional_information") and \
self._forward_additional_information is not None and \
isinstance(self._forward_additional_information, dict):
model_kwargs_extra["additional_information"] = self._forward_additional_information
model_output = self.model(
input_ids=input_ids,
positions=positions,
intermediate_tensors=intermediate_tensors,
inputs_embeds=inputs_embeds,
**MultiModalKwargs.as_kwargs(
model_mm_kwargs,
device=self.device,
),
sampling_metadata=self.input_batch.sampling_metadata,
logits_index=logits_indices,
sampler=self.sampler,
**model_kwargs_extra,
)
if self.use_aux_hidden_state_outputs:
hidden_states, _aux_hidden_states = model_output
else:
hidden_states = model_output
_aux_hidden_states = None
text_hidden_states, multimodal_outputs = (
self.extract_multimodal_outputs(hidden_states))
# Mid PP stages return intermediate tensors unmodified
if not get_pp_group().is_last_rank:
assert isinstance(text_hidden_states, IntermediateTensors)
text_hidden_states.kv_connector_output = kv_connector_output
return text_hidden_states
# Broadcast PP output for external_launcher (torchrun)
broadcast_pp_output = \
self.parallel_config.distributed_executor_backend \
== "external_launcher" and len(get_pp_group().ranks) > 0
if not get_pp_group().is_last_rank:
assert isinstance(text_hidden_states, IntermediateTensors)
if not broadcast_pp_output:
text_hidden_states.kv_connector_output = kv_connector_output
return text_hidden_states
get_pp_group().send_tensor_dict(text_hidden_states.tensors,
all_gather_group=get_tp_group())
logits = None
else:
if self.input_batch.pooling_params:
return self._pool(text_hidden_states, num_scheduled_tokens,
num_scheduled_tokens_np, kv_connector_output)
sample_hidden_states = text_hidden_states[logits_indices]
logits = self.model.compute_logits(sample_hidden_states, None)
if broadcast_pp_output:
model_output_broadcast_data = {
"logits": logits.contiguous(),
} if logits is not None else {}
model_output_broadcast_data = get_pp_group().broadcast_tensor_dict(
model_output_broadcast_data, src=len(get_pp_group().ranks) - 1)
assert model_output_broadcast_data is not None
logits = model_output_broadcast_data["logits"]
# Apply structured output bitmasks if present
if scheduler_output.grammar_bitmask is not None:
self.apply_grammar_bitmask(scheduler_output, logits)
# Sample the next token and get logprobs if needed (with spec decode)
sampling_metadata = self.input_batch.sampling_metadata
if spec_decode_metadata is None:
sampler_output = self.sampler(
logits=logits,
sampling_metadata=sampling_metadata,
)
else:
assert logits is not None
bonus_logits = logits[spec_decode_metadata.bonus_logits_indices]
sampler_output = self.sampler(
logits=bonus_logits,
sampling_metadata=sampling_metadata,
)
bonus_token_ids = sampler_output.sampled_token_ids
target_logits = logits[spec_decode_metadata.target_logits_indices]
output_token_ids = self.rejection_sampler(
spec_decode_metadata,
None,
target_logits,
bonus_token_ids,
sampling_metadata,
)
sampler_output.sampled_token_ids = output_token_ids
num_nans_in_logits = {}
if envs.VLLM_COMPUTE_NANS_IN_LOGITS:
num_nans_in_logits = self._get_nans_in_logits(logits)
# Handle partial prefill: discard sampled tokens and rewind RNG
discard_sampled_tokens_req_indices = []
for i, req_id in enumerate(self.input_batch.req_ids):
req_state = self.requests[req_id]
seq_len = (req_state.num_computed_tokens +
scheduler_output.num_scheduled_tokens[req_id])
if seq_len < req_state.num_tokens:
generator = self.input_batch.generators.get(i)
if generator is not None:
generator.set_offset(generator.get_offset() - 4)
discard_sampled_tokens_req_indices.append(i)
# Move CPU sync parts
logprobs_tensors = sampler_output.logprobs_tensors
logprobs_lists = logprobs_tensors.tolists() \
if logprobs_tensors is not None else None
# Prompt logprobs if needed
prompt_logprobs_dict = self._get_prompt_logprobs_dict(
text_hidden_states[:num_scheduled_tokens],
scheduler_output,
)
# Parse valid sampled tokens
sampled_token_ids = sampler_output.sampled_token_ids
max_gen_len = sampled_token_ids.shape[-1]
if max_gen_len == 1:
valid_sampled_token_ids = sampled_token_ids.tolist()
else:
valid_sampled_token_ids = self.rejection_sampler.parse_output(
sampled_token_ids,
self.input_batch.vocab_size,
)
for i in discard_sampled_tokens_req_indices:
valid_sampled_token_ids[i].clear()
# Cache sampled tokens
for req_idx, sampled_ids in enumerate(valid_sampled_token_ids):
if not sampled_ids:
continue
start_idx = self.input_batch.num_tokens_no_spec[req_idx]
end_idx = start_idx + len(sampled_ids)
self.input_batch.token_ids_cpu[req_idx, start_idx:end_idx] = sampled_ids
self.input_batch.num_tokens_no_spec[req_idx] = end_idx
self.input_batch.num_tokens[req_idx] = end_idx
req_id = self.input_batch.req_ids[req_idx]
req_state = self.requests[req_id]
req_state.output_token_ids.extend(sampled_ids)
# Speculative decoding draft tokens if configured
if not self.speculative_config:
spec_token_ids = None
else:
assert spec_decode_common_attn_metadata is not None
spec_token_ids = self.propose_draft_token_ids(
scheduler_output,
valid_sampled_token_ids,
sampling_metadata,
text_hidden_states,
sample_hidden_states,
_aux_hidden_states,
spec_decode_metadata,
spec_decode_common_attn_metadata,
)
# Convert to per-request tensors on CPU
text_hidden_states_cpu = text_hidden_states.detach().to("cpu").contiguous()
pooler_output: list[Optional[torch.Tensor]] = []
prev_logits_index = 0
for logits_index in logits_indices:
pooler_output.append(text_hidden_states_cpu[prev_logits_index:logits_index+1])
prev_logits_index = logits_index + 1
self.eplb_step()
return OmniModelRunnerOutput(
req_ids=self.input_batch.req_ids,
req_id_to_index=self.input_batch.req_id_to_index,
sampled_token_ids=valid_sampled_token_ids,
spec_token_ids=spec_token_ids,
logprobs=logprobs_lists,
prompt_logprobs_dict=prompt_logprobs_dict,
pooler_output=pooler_output if self.vllm_config.model_config.engine_output_type != "text" else None,
kv_connector_output=kv_connector_output,
num_nans_in_logits=num_nans_in_logits,
)
@torch.inference_mode()
def extract_multimodal_outputs(self, hidden_states: Union[torch.Tensor, List[torch.Tensor]]) -> dict:
if hasattr(self.model, "have_multimodal_outputs") and self.model.have_multimodal_outputs:
text_hidden_states = hidden_states.text_hidden_states
multimodal_outputs = hidden_states.multimodal_outputs
elif isinstance(hidden_states, torch.Tensor):
text_hidden_states = hidden_states
multimodal_outputs = {}
elif isinstance(hidden_states, List):
text_hidden_states = hidden_states[0]
multimodal_outputs = {}
else:
raise ValueError(f"Invalid hidden states type: {type(hidden_states)}")
return text_hidden_states, multimodal_outputs
@torch.inference_mode()
def _dummy_run(
self,
num_tokens: int,
capture_attn_cudagraph: bool = False,
skip_eplb: bool = False,
is_profile: bool = False,
) -> tuple[torch.Tensor, torch.Tensor]:
# Padding for DP
num_pad, num_tokens_across_dp = self.get_dp_padding(num_tokens)
num_tokens += num_pad
# Set num_scheduled_tokens based on num_tokens and max_num_seqs
# for dummy run with LoRA so that the num_reqs collectively
# has num_tokens in total.
assert num_tokens <= self.scheduler_config.max_num_batched_tokens
max_num_reqs = self.scheduler_config.max_num_seqs
num_reqs = min(num_tokens, max_num_reqs)
min_tokens_per_req = num_tokens // num_reqs
num_scheduled_tokens_list = [min_tokens_per_req] * num_reqs
num_scheduled_tokens_list[-1] += num_tokens % num_reqs
assert sum(num_scheduled_tokens_list) == num_tokens
assert len(num_scheduled_tokens_list) == num_reqs
num_scheduled_tokens = np.array(num_scheduled_tokens_list,
dtype=np.int32)
attn_metadata: Optional[dict[str, Any]] = None
if capture_attn_cudagraph:
attn_metadata = {}
# Make sure max_model_len is used at the graph capture time.
self.seq_lens_np[:num_reqs] = self.max_model_len
self.seq_lens_np[num_reqs:] = 0
self.seq_lens[:num_reqs].copy_(self.seq_lens_cpu[:num_reqs],
non_blocking=True)
for kv_cache_group_id, kv_cache_group_spec in enumerate(
self.kv_cache_config.kv_cache_groups):
common_attn_metadata = CommonAttentionMetadata(
query_start_loc=self.query_start_loc[:num_reqs + 1],
query_start_loc_cpu=self.query_start_loc_cpu[:num_reqs +
1],
seq_lens=self.seq_lens[:num_reqs],
seq_lens_cpu=self.seq_lens_cpu[:num_reqs],
num_computed_tokens_cpu=self.input_batch.
num_computed_tokens_cpu_tensor[:num_reqs],
num_reqs=num_reqs,
num_actual_tokens=num_tokens,
max_query_len=num_tokens,
block_table_tensor=self.input_batch.block_table[
kv_cache_group_id].get_device_tensor()[:num_reqs],
slot_mapping=self.input_batch.
block_table[kv_cache_group_id].slot_mapping[:num_tokens],
causal=True)
for attn_group in self.attn_groups[kv_cache_group_id]:
attn_metadata_i = attn_group.metadata_builder\
.build_for_cudagraph_capture(common_attn_metadata)
for layer_name in kv_cache_group_spec.layer_names:
attn_metadata[layer_name] = attn_metadata_i
with self.maybe_dummy_run_with_lora(self.lora_config,
num_scheduled_tokens):
if self.is_multimodal_model:
input_ids = None
inputs_embeds = self.inputs_embeds[:num_tokens]
model_mm_kwargs = self._dummy_mm_kwargs(num_reqs)
else:
input_ids = self.input_ids[:num_tokens]
inputs_embeds = None
model_mm_kwargs = {}
if self.uses_mrope:
positions = self.mrope_positions[:, :num_tokens]
else:
positions = self.positions[:num_tokens]
if get_pp_group().is_first_rank:
intermediate_tensors = None
else:
if self.intermediate_tensors is None:
self.intermediate_tensors = (
self.model.make_empty_intermediate_tensors(
batch_size=self.max_num_tokens,
dtype=self.model_config.dtype,
device=self.device))
intermediate_tensors = self.sync_and_slice_intermediate_tensors(
num_tokens, None, False)
with self.maybe_randomize_inputs(input_ids), set_forward_context(
attn_metadata,
self.vllm_config,
num_tokens=num_tokens,
num_tokens_across_dp=num_tokens_across_dp):
outputs = self.model(
input_ids=input_ids,
positions=positions,
intermediate_tensors=intermediate_tensors,
inputs_embeds=inputs_embeds,
**MultiModalKwargs.as_kwargs(
model_mm_kwargs,
device=self.device,
),
)
if self.use_aux_hidden_state_outputs:
hidden_states, _ = outputs
else:
hidden_states = outputs
if self.speculative_config and self.speculative_config.use_eagle():
assert isinstance(self.drafter, EagleProposer)
self.drafter.dummy_run(num_tokens)
# This is necessary to avoid blocking DP.
# For dummy runs, we typically skip EPLB since we don't have any real
# requests to process.
# However, in DP settings, there may be cases when some DP ranks do
# not have any requests to process, so they're executing dummy batches.
# In such cases, we still have to trigger EPLB to make sure
# ranks execute the rearrangement in synchronization.
if not skip_eplb:
self.eplb_step(is_dummy=True, is_profile=is_profile)
logit_indices = np.cumsum(num_scheduled_tokens) - 1
hidden_states, multimodal_outputs = self.extract_multimodal_outputs(hidden_states)
return hidden_states, hidden_states[logit_indices]