Files
vllm-omni/vllm_omni/worker/gpu_diffusion_model_runner.py
T
tzhouam 2cc33bb3ea Fix tensor handling in DiffusionModelRunner for multimodal outputs
- Updated assertions and tensor management to correctly handle multimodal outputs in the `DiffusionModelRunner` class.
- Ensured that the output tensors are processed based on the type of multimodal outputs received, improving robustness and clarity in the code.
2025-10-22 17:38:49 +08:00

377 lines
15 KiB
Python

# SPDX-License-Identifier: Apache-2.0
from __future__ import annotations
from typing import Optional, Union, List
import numpy as np
import gc
import logging
import torch
from vllm.v1.worker.gpu_model_runner import (
GPUModelRunner,
EMPTY_MODEL_RUNNER_OUTPUT,
IntermediateTensors,
get_pp_group,
has_kv_transfer_group,
set_forward_context,
)
from vllm.v1.worker.utils import sanity_check_mm_encoder_outputs
from vllm.multimodal.inputs import MultiModalKwargs
from vllm.v1.core.sched.output import SchedulerOutput
from vllm.v1.attention.backends.utils import CommonAttentionMetadata
from vllm_omni.outputs import OmniModelRunnerOutput
from vllm_omni.worker.gpu_model_runner import OmniGPUModelRunner
logger = logging.getLogger(__name__)
class DiffusionModelRunner(OmniGPUModelRunner):
"""Diffusion model runner for vLLM-omni (non-autoregressive).
- Reuses GPUModelRunner preparation, multimodal handling, and TP/PP/DP glue.
- Does not compute logits or perform token sampling.
- Executes diffusion process and returns tensors via `pooler_output`.
"""
@torch.inference_mode()
def execute_model(
self,
scheduler_output: "SchedulerOutput",
intermediate_tensors: Optional[IntermediateTensors] = None,
) -> Union[OmniModelRunnerOutput, IntermediateTensors]:
self._update_states(scheduler_output)
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 (for batch/order mapping)
(attn_metadata, attention_cuda_graphs, logits_indices,
spec_decode_metadata, num_scheduled_tokens_np,
spec_decode_common_attn_metadata) = self._prepare_inputs(
scheduler_output)
# Input token count for this iteration (not used by diffusion, but
# retained to keep DP padding/ordering consistent)
num_input_tokens = scheduler_output.total_num_scheduled_tokens
num_pad, num_tokens_across_dp = self.get_dp_padding(num_input_tokens)
num_input_tokens += num_pad
# Multimodal conditioning (e.g., text/audio/video encoders)
if self.is_multimodal_model:
self._execute_mm_encoder(scheduler_output)
mm_embeds = self._gather_mm_embeddings(scheduler_output)
else:
mm_embeds = []
# Build inputs to mirror AR runner: input_ids/positions/embeds
if self.is_multimodal_model and get_pp_group().is_first_rank:
inputs_embeds_scheduled = self.model.get_input_embeddings(
input_ids=self.input_ids[:scheduler_output.total_num_scheduled_tokens],
multimodal_embeddings=mm_embeds or None,
)
self.inputs_embeds[:scheduler_output.total_num_scheduled_tokens].copy_(
inputs_embeds_scheduled)
input_ids = self.input_ids[:num_input_tokens]
inputs_embeds = self.inputs_embeds[:num_input_tokens]
model_mm_kwargs = self._extract_mm_kwargs(scheduler_output)
else:
input_ids = self.input_ids[:num_input_tokens]
inputs_embeds = None
model_mm_kwargs = {}
# Positions (mrope or standard)
if self.uses_mrope:
positions = self.mrope_positions[:, :num_input_tokens]
else:
positions = self.positions[:num_input_tokens]
# Intermediate tensors sync for PP (if any)
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)
# Set forward context mainly for resource management and kv connector
skip_cuda_graphs = True # diffusion path does not rely on cuda graphs here
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:
if not get_pp_group().is_last_rank:
# For non-last PP stages, pass through intermediate tensors.
assert intermediate_tensors is not None
intermediate_tensors.kv_connector_output = kv_connector_output
return intermediate_tensors
outputs = self._run_diffusion(
input_ids=input_ids,
positions=positions,
intermediate_tensors=intermediate_tensors,
inputs_embeds=inputs_embeds,
multimodal_kwargs=model_mm_kwargs,
logits_indices=logits_indices,
)
_, multimodal_outputs = (
self.extract_multimodal_outputs(outputs))
# Ensure one tensor per request, map to CPU for output struct
pooler_output: List[Optional[torch.Tensor]] = []
if isinstance(multimodal_outputs, torch.Tensor):
# If model returned a single stacked tensor, split by requests
assert multimodal_outputs.shape[0] == self.input_batch.num_reqs
for i in range(self.input_batch.num_reqs):
pooler_output.append(multimodal_outputs[i].detach().to("cpu").contiguous())
elif isinstance(multimodal_outputs, list):
for out in multimodal_outputs:
pooler_output.append(out.detach().to("cpu").contiguous() if out is not None else None)
elif isinstance(multimodal_outputs, dict):
for out in multimodal_outputs.values():
pooler_output.append(out.detach().to("cpu").contiguous() if out is not None else None)
else:
raise RuntimeError("Unsupported diffusion output type")
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=[],
spec_token_ids=None,
logprobs=None,
prompt_logprobs_dict={},
pooler_output=pooler_output,
kv_connector_output=kv_connector_output,
num_nans_in_logits={},
)
def _run_diffusion(
self,
*,
input_ids: torch.Tensor,
positions: torch.Tensor,
intermediate_tensors: Optional[IntermediateTensors],
inputs_embeds: Optional[torch.Tensor],
multimodal_kwargs: dict,
logits_indices: torch.Tensor,
) -> Union[torch.Tensor, list[torch.Tensor]]:
"""Runs the diffusion process and returns per-request tensors.
Tries model interfaces in the following order for maximal compatibility:
1) model.sample(condition=..., **kwargs)
2) model.forward(condition=..., **kwargs)
3) model.diffuse(condition=..., **kwargs)
"""
# Keep inputs identical to AR runner
kwargs = dict(
input_ids=input_ids,
positions=positions,
intermediate_tensors=intermediate_tensors,
inputs_embeds=inputs_embeds,
**MultiModalKwargs.as_kwargs(multimodal_kwargs, device=self.device),
sampling_metadata=self.input_batch.sampling_metadata,
logits_index=logits_indices,
sampler=self.sampler,
)
# For Qwen 2.5 Omni's current implementation, we only support the forward method
if hasattr(self.model, "forward"):
return self.model.forward(**kwargs)
# if hasattr(self.model, "sample"):
# return self.model.sample(**kwargs)
# if hasattr(self.model, "forward"):
# return self.model.forward(**kwargs)
# if hasattr(self.model, "diffuse"):
# return self.model.diffuse(**kwargs)
raise RuntimeError(
"The loaded model does not expose diffusion interfaces 'sample', "
"'forward', or 'diffuse'. Please implement one of them or adapt the runner.")
@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, dict]] = 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)
# Diffusion path: avoid CUDA graphs; we only use context for resource wiring
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,
),
sampler=None,
)
if self.use_aux_hidden_state_outputs:
hidden_states, _ = outputs
else:
hidden_states = outputs
# Extract multimodal outputs if present; we ignore them here because
# dummy run returns tensors only. The actual diffusion runner returns
# multimodal outputs via pooler_output in execute_model.
text_hidden_states, _ = self.extract_multimodal_outputs(hidden_states)
if not skip_eplb:
self.eplb_step(is_dummy=True, is_profile=is_profile)
logit_indices = np.cumsum(num_scheduled_tokens) - 1
return text_hidden_states, None
@torch.inference_mode()
def _dummy_sampler_run(self, hidden_states: torch.Tensor) -> None:
logger.warning("Dummy sampler run is not implemented for diffusion model")
return None
def profile_run(self) -> None:
# Profile with multimodal encoder & encoder cache, similar to base but
# without any logits/sampler warming.
if self.is_multimodal_model:
mm_budget = self.mm_budget
assert mm_budget is not None
# TODO: handle encoder-decoder models once supported.
if (encoder_budget := mm_budget.get_encoder_budget()) > 0:
(
dummy_modality,
max_tokens,
) = mm_budget.get_modality_with_max_tokens()
(
max_mm_items_per_prompt,
max_mm_items_per_batch,
) = mm_budget.get_max_items(dummy_modality, max_tokens)
batched_dummy_mm_inputs = self._get_mm_dummy_batch(
dummy_modality,
max_mm_items_per_batch,
)
dummy_encoder_outputs = self.model.get_multimodal_embeddings(
**batched_dummy_mm_inputs)
sanity_check_mm_encoder_outputs(
dummy_encoder_outputs,
expected_num_items=max_mm_items_per_batch,
)
self.encoder_cache["tmp"] = dict(
enumerate(dummy_encoder_outputs))
hidden_states, _ = self._dummy_run(self.max_num_tokens, is_profile=True)
if get_pp_group().is_last_rank:
pass # No sampler/pooler warmup for diffusion
self._sync_device()
del hidden_states
self.encoder_cache.clear()
gc.collect()