Files
xc-llm-ascend/vllm_ascend/spec_decode/mtp_proposer.py
whx e9bb4491ec [BugFix] Fix deepseek v3.2 mtp bug. (#3900)
### What this PR does / why we need it?
This PR fixes deepseek v3.2 mtp bug.

### Does this PR introduce _any_ user-facing change?
None

### How was this patch tested?
All existed ci tests should pass.

- vLLM version: v0.11.0
- vLLM main:
83f478bb19

---------

Signed-off-by: whx-sjtu <2952154980@qq.com>
2025-11-04 14:06:59 +08:00

887 lines
42 KiB
Python

from typing import Optional
import numpy as np
import torch
import torch.nn as nn
import torch.nn.functional as F
from vllm.config import (CUDAGraphMode, VllmConfig,
get_layers_from_vllm_config, set_current_vllm_config)
from vllm.forward_context import BatchDescriptor
from vllm.logger import init_logger
from vllm.model_executor.layers.attention_layer_base import AttentionLayerBase
from vllm.model_executor.model_loader import get_model_loader
from vllm.model_executor.model_loader.utils import \
process_weights_after_loading
from vllm.model_executor.models.deepseek_mtp import DeepSeekMTP
from vllm.model_executor.models.deepseek_v2 import DeepseekV32IndexerCache
from vllm.model_executor.models.llama_eagle3 import Eagle3LlamaForCausalLM
from vllm.utils import cdiv
from vllm.v1.attention.backends.utils import (AttentionMetadataBuilder,
CommonAttentionMetadata)
from vllm.v1.core.sched.output import SchedulerOutput
from vllm.v1.sample.metadata import SamplingMetadata
from vllm.v1.spec_decode.metadata import SpecDecodeMetadata
from vllm.v1.utils import CpuGpuBuffer
from vllm.v1.worker.gpu_input_batch import CachedRequestState, InputBatch
from vllm_ascend.ascend_forward_context import set_ascend_forward_context
from vllm_ascend.attention.utils import (AscendCommonAttentionMetadata,
AscendPrefillContextParallelMetadata)
from vllm_ascend.spec_decode.interface import Proposer, SpecDcodeType
from vllm_ascend.utils import (ProfileExecuteDuration, lmhead_tp_enable,
vllm_version_is)
if vllm_version_is("0.11.0"):
from vllm.model_executor.model_loader.utils import set_default_torch_dtype
from vllm.utils import is_pin_memory_available
else:
from vllm.utils.platform_utils import is_pin_memory_available
from vllm.utils.torch_utils import set_default_torch_dtype
logger = init_logger(__name__)
PADDING_SLOT_ID = -1
class MtpProposer(Proposer):
def __init__(
self,
vllm_config: VllmConfig,
device,
runner,
):
self.name = SpecDcodeType.MTP
self.vllm_config = vllm_config
self.speculative_config = vllm_config.speculative_config
assert self.speculative_config is not None
self.draft_model_config = self.speculative_config.draft_model_config
self.method = self.speculative_config.method
self.runner = runner
self.device = device
self.dtype = vllm_config.model_config.dtype
self.max_model_len = vllm_config.model_config.max_model_len
self.block_size = vllm_config.cache_config.block_size
self.num_speculative_tokens = self.speculative_config.num_speculative_tokens
self.max_num_tokens = vllm_config.scheduler_config.max_num_batched_tokens
self.token_arange_np = np.arange(self.max_num_tokens)
# We need to get the hidden size from the draft model config because
# the draft model's hidden size can be different from the target model's
# hidden size (e.g., Llama 3.3 70B).
self.hidden_size = self.draft_model_config.get_hidden_size()
self.pcp_size = self.runner.pcp_size
self.dcp_size = self.runner.dcp_size
self.pcp_rank = self.runner.pcp_rank
self.attn_metadata_builder: Optional[AttentionMetadataBuilder] = None
self.draft_indexer_metadata_builder: Optional[
AttentionMetadataBuilder] = None
self.attn_layer_names: list[str] = []
self.indexer_layer_names: list[str] = []
self.use_aclgraph = self.runner._use_aclgraph()
self.cudagraph_batch_sizes = (list(
reversed(
self.vllm_config.compilation_config.cudagraph_capture_sizes))
if self.use_aclgraph else [])
# persistent buffers for aclgraph graph
self.input_ids = torch.zeros(self.max_num_tokens,
dtype=torch.int32,
device=device)
self.uses_mrope = self.vllm_config.model_config.uses_mrope
if self.uses_mrope:
# M-RoPE need (3, max_num_tokens)
self.mrope_positions = torch.zeros((3, self.max_num_tokens),
dtype=torch.int64,
device=device)
else:
# RoPE need (max_num_tokens,)
self.positions = torch.zeros(self.max_num_tokens,
dtype=torch.int64,
device=device)
self.hidden_states = torch.zeros(
(self.max_num_tokens, self.hidden_size),
dtype=self.dtype,
device=device)
self.full_indices = range(
self.runner.max_num_tokens * self.pcp_size * self.dcp_size +
self.pcp_size * self.dcp_size * self.runner.max_num_reqs)
# We need +1 here because the arange is used to set query_start_loc,
# which has one more element than batch_size.
max_batch_size = vllm_config.scheduler_config.max_num_seqs
max_num_slots_for_arange = max(max_batch_size + 1, self.max_num_tokens)
self.arange = torch.arange(max_num_slots_for_arange,
device=device,
dtype=torch.int32)
self.inputs_embeds = torch.zeros(
(self.max_num_tokens, self.hidden_size),
dtype=self.dtype,
device=device)
self.backup_next_token_ids = CpuGpuBuffer(
max_batch_size,
dtype=torch.int32,
pin_memory=is_pin_memory_available(),
device=device,
with_numpy=True,
)
self.use_sparse = hasattr(vllm_config.model_config.hf_config,
"index_topk")
def load_model(self, model) -> None:
loader = get_model_loader(self.vllm_config.load_config)
target_attn_layer_names = set(
get_layers_from_vllm_config(self.vllm_config,
AttentionLayerBase).keys())
target_indexer_layer_names = set(
get_layers_from_vllm_config(self.vllm_config,
DeepseekV32IndexerCache).keys())
draft_model_config = \
self.vllm_config.speculative_config.draft_model_config
target_device = self.vllm_config.device_config.device
with set_default_torch_dtype(
draft_model_config.dtype), set_current_vllm_config(
self.vllm_config):
self.model = DeepSeekMTP(
vllm_config=self.vllm_config).to(target_device)
draft_attn_layer_names = (get_layers_from_vllm_config(
self.vllm_config, AttentionLayerBase).keys() -
target_attn_layer_names)
indexer_layers = get_layers_from_vllm_config(self.vllm_config,
DeepseekV32IndexerCache)
draft_indexer_layer_names = indexer_layers.keys(
) - target_indexer_layer_names
# NOTE: Currently we don't have specific attention backend and attention metadata
# for deepseek v3.2 indexer, so we just exclude the indexer layers here.
draft_attn_layer_names = draft_attn_layer_names - draft_indexer_layer_names
assert len(draft_attn_layer_names) == 1
self.attn_layer_name = list(draft_attn_layer_names)
self.model.load_weights(
loader.get_all_weights(
self.vllm_config.speculative_config.draft_model_config,
self.model))
process_weights_after_loading(self.model, draft_model_config,
target_device)
@torch.inference_mode()
def dummy_run(self,
num_tokens: int,
with_prefill: bool = False,
skip_attn: bool = False,
num_reqs: int = 0,
num_tokens_across_dp=None,
aclgraph_runtime_mode: CUDAGraphMode = CUDAGraphMode.NONE,
batch_descriptor=None) -> None:
(
num_tokens,
num_tokens_across_dp,
with_prefill,
) = self.runner._sync_metadata_across_dp(num_tokens, with_prefill)
moe_comm_type = self.runner._select_moe_comm_method(
num_tokens, with_prefill)
attn_metadata = None
input_ids = self.input_ids[:num_tokens]
positions = self.positions[:num_tokens]
previous_hidden_states = self.hidden_states[:num_tokens]
for _ in range(self.num_speculative_tokens):
with set_ascend_forward_context(
attn_metadata,
self.vllm_config,
num_tokens=num_tokens,
with_prefill=with_prefill,
num_tokens_across_dp=num_tokens_across_dp,
reserved_mc2_mask=self.runner.reserved_mc2_mask,
moe_comm_type=moe_comm_type,
in_profile_run=self.runner.in_profile_run,
num_actual_tokens=0,
aclgraph_runtime_mode=aclgraph_runtime_mode,
batch_descriptor=batch_descriptor):
self.model(input_ids=input_ids,
positions=positions,
hidden_states=previous_hidden_states)
if with_prefill:
break
def generate_token_ids(self,
sampled_token_ids: list[list[int]],
sampling_metadata: SamplingMetadata = None,
scheduler_output: SchedulerOutput = None,
spec_decode_metadata: SpecDecodeMetadata = None,
positions: torch.Tensor = None,
num_scheduled_tokens: int = 0,
hidden_states: torch.Tensor = None,
attn_metadata=None,
aux_hidden_states: torch.Tensor = None):
common_attn_metadata = self.runner.spec_decode_common_attn_metadata
if attn_metadata is not None and isinstance(attn_metadata, dict):
attn_metadata = attn_metadata['model.layers.0.self_attn.attn']
if self.speculative_config.disable_padded_drafter_batch:
# When padded-batch is disabled, the sampled_token_ids should be
# the cpu-side list[list[int]] of valid sampled tokens for each
# request, with invalid requests having empty lists.
assert isinstance(sampled_token_ids, list), \
"sampled_token_ids should be a python list when" \
"padded-batch is disabled."
next_token_ids = self.prepare_next_token_ids_cpu(
sampled_token_ids, self.runner.requests,
self.runner.input_batch, scheduler_output.num_scheduled_tokens)
else:
# When using padded-batch, the sampled_token_ids should be
# the gpu tensor of sampled tokens for each request, of shape
# (num_reqs, num_spec_tokens + 1) with rejected tokens having
# value -1.
assert isinstance(sampled_token_ids, torch.Tensor), \
"sampled_token_ids should be a torch.Tensor when" \
"padded-batch is enabled."
next_token_ids, valid_sampled_tokens_count = \
self.prepare_next_token_ids_padded(
common_attn_metadata,
sampled_token_ids,
self.runner.requests,
self.runner.input_batch,
self.runner.discard_request_indices.gpu,
self.runner.num_discarded_requests
)
is_prefill = len(scheduler_output.scheduled_new_reqs) > 0
req_scheduled_tokens = scheduler_output.num_scheduled_tokens
long_seq_metadata: AscendPrefillContextParallelMetadata = \
self.runner.long_seq_metadata if self.pcp_size > 1 else None
if spec_decode_metadata is None:
# update pcp related params
if self.pcp_size > 1 and is_prefill:
token_indices_to_sample = None
target_token_ids = self.runner.input_ids_pcp_full[:
num_scheduled_tokens]
target_positions = positions[:num_scheduled_tokens]
target_hidden_states = hidden_states
else:
token_indices_to_sample = None
# input_ids can be None for multimodal models.
target_token_ids = self.runner.input_ids[:num_scheduled_tokens]
target_positions = positions[:num_scheduled_tokens]
target_hidden_states = hidden_states[:num_scheduled_tokens]
else:
if self.speculative_config.disable_padded_drafter_batch:
token_indices_to_sample = None
common_attn_metadata, token_indices =\
self._prepare_inputs(
common_attn_metadata,
sampled_token_ids,
spec_decode_metadata.num_draft_tokens)
else:
common_attn_metadata, token_indices, \
token_indices_to_sample =\
self.prepare_inputs_padded(
common_attn_metadata,
spec_decode_metadata,
valid_sampled_tokens_count)
target_token_ids = self.runner.input_ids[token_indices]
target_positions = positions[token_indices]
target_hidden_states = hidden_states[token_indices]
draft_token_ids = self._propose(
target_token_ids=target_token_ids,
target_positions=target_positions,
target_hidden_states=target_hidden_states,
next_token_ids=next_token_ids,
last_token_indices=token_indices_to_sample,
common_attn_metadata=common_attn_metadata,
sampling_metadata=sampling_metadata,
is_prefill=is_prefill,
req_scheduled_tokens=req_scheduled_tokens,
long_seq_metadata=long_seq_metadata,
)
return draft_token_ids
def _prepare_inputs(
self,
common_attn_metadata: CommonAttentionMetadata,
sampled_token_ids: list[list[int]],
num_draft_tokens: list[int],
) -> tuple[CommonAttentionMetadata, torch.Tensor]:
"""
This function is used to prepare the inputs for speculative decoding.
It updates to the common_attn_metadata to account for the rejected
tokens (and newly sampled tokens). It also returns the token indices
of the tokens that should be fed to the speculator.
"""
# E.g.
# common_attn_metadata.query_start_loc{_cpu}:
# [0, q1, q1 + q2, q1 + q2 + q3]
# common_attn_metadata.seq_lens{_cpu}: [s1, s2, s3]
# num_rejected_tokens: [n1, n2, n3]
# This function computes the intermediate values:
# num_tokens_per_req: [q1 - n1, q2 - n2, q3 - n3]
# And returns:
# common_attn_metadata.query_start_loc{_cpu}:
# [0, q1 - n1, q1 + q2 - n1 - n2, q1 + q2 + q3 - n1 - n2 - n3]
# common_attn_metadata.seq_lens{_cpu}:
# [s1 - n1 + 1, s2 - n2 + 1, s3 - n3 + 1]
# token_indices: [0, 1, ..., q1 - n1 - 1,
# q1, q1 + 1, ..., q1 + q2 - n2 - 1,
# q1 + q2, q1 + q2 + 1, ..., q1 + q2 + q3 - n3 - 1]
num_rejected_tokens = [
n + 1 - len(sampled_token_ids[i]) if n > 0 else 0
for i, n in enumerate(num_draft_tokens)
]
num_rejected_tokens = torch.tensor(num_rejected_tokens,
dtype=torch.int32)
device = common_attn_metadata.query_start_loc.device
query_start_loc_cpu = common_attn_metadata.query_start_loc_cpu
new_seq_lens_cpu = common_attn_metadata.seq_lens_cpu - num_rejected_tokens
# [0, q1, q1 + q2, q1 + q2 + q3] -> [q1, q2, q3]
new_query_len_per_req = query_start_loc_cpu[
1:] - query_start_loc_cpu[:-1]
# [q1, q2, q3] -> [q1 - n1, q2 - n2, q3 - n3]
new_num_tokens_per_req = new_query_len_per_req - num_rejected_tokens
new_num_tokens_per_req_np = new_num_tokens_per_req.numpy()
# [q1 - n1, q2 - n2, q3 - n3] ->
# [0, q1 - n1, q1 + q2 - n1 - n2, q1 + q2 + q3 - n1 - n2 - n3]
new_query_start_loc_cpu = torch.zeros(
query_start_loc_cpu.shape,
dtype=torch.int32,
pin_memory=is_pin_memory_available(),
)
new_query_start_loc_np = new_query_start_loc_cpu.numpy()
np.cumsum(new_num_tokens_per_req_np, out=new_query_start_loc_np[1:])
total_num_tokens = new_query_start_loc_np[-1]
# Example assuming num_tokens_per_req_np = [2, 4, 3]
# this implies that `new_query_start_locs` is:
# [0, 2, 6, 9] ->
# [0, 0, 2, 2, 2, 2, 6, 6, 6]
# _r1_ ____r2____ ___r3__
new_query_start_locs_expanded = np.repeat(new_query_start_loc_np[:-1],
new_num_tokens_per_req_np)
# [0, 1, 2, 3, 4, 5, 6, 7, 8] ->
# [0, 1, 0, 1, 2, 3, 0, 1, 2]
# _r1_ ____r2____ ___r3__
token_offests = (self.token_arange_np[:total_num_tokens] -
new_query_start_locs_expanded)
# Expand starting positions to match token pattern
# [0, q1, q1 + q2] ->
# [0, 0, q1, q1, q1, q1, q1 + q2, q1 + q2, q1 + q2]
# _r1_ _____r2_______ ___________r3____________
old_query_start_locs_expanded = np.repeat(
query_start_loc_cpu[:-1].numpy(), new_num_tokens_per_req_np)
# Final token indices are:
# [0, 1, // req 1
# q1 + 0, q1 + 1, q1 + 2, q1 + 3, // req 2
# q1 + q2 + 0, q1 + q2 + 1, q1 + q2 + 2] // req 3
token_indices_np = token_offests + old_query_start_locs_expanded
token_indices = torch.from_numpy(token_indices_np).to(
device, non_blocking=True)
spec_common_attn_metadata = AscendCommonAttentionMetadata(
query_start_loc=new_query_start_loc_cpu.to(device,
non_blocking=True),
query_start_loc_cpu=new_query_start_loc_cpu,
seq_lens=new_seq_lens_cpu.to(device, non_blocking=True),
seq_lens_cpu=new_seq_lens_cpu,
num_computed_tokens_cpu=common_attn_metadata.
num_computed_tokens_cpu,
num_reqs=common_attn_metadata.num_reqs,
num_actual_tokens=total_num_tokens,
max_query_len=new_query_len_per_req.max().item(),
block_table_tensor=common_attn_metadata.block_table_tensor,
slot_mapping=common_attn_metadata.slot_mapping[token_indices],
actual_seq_lengths_q=self.runner.actual_seq_lengths_q,
positions=common_attn_metadata.positions[token_indices],
attn_mask=self.runner.attn_mask,
spec_attn_mask=self.runner.spec_attn_mask,
attn_state=self.runner.attn_state,
graph_pad_size=self.runner.graph_pad_size,
decode_token_per_req=self.runner.decode_token_per_req,
)
return spec_common_attn_metadata, token_indices
def _propose(
self,
# [num_tokens]
target_token_ids: torch.Tensor,
# [num_tokens] or [3, num_tokens] when M-RoPE is enabled
target_positions: torch.Tensor,
# [num_tokens, hidden_size]
target_hidden_states: torch.Tensor,
# [batch_size]
next_token_ids: torch.Tensor,
last_token_indices: Optional[torch.Tensor],
common_attn_metadata: CommonAttentionMetadata,
sampling_metadata: SamplingMetadata,
mm_embed_inputs: Optional[tuple[list[torch.Tensor],
torch.Tensor]] = None,
is_prefill=False,
req_scheduled_tokens=None,
long_seq_metadata=None,
) -> torch.Tensor:
num_tokens = target_token_ids.shape[0]
batch_size = next_token_ids.shape[0]
if last_token_indices is None:
last_token_indices = common_attn_metadata.query_start_loc[1:] - 1
if self.method == "eagle3":
assert isinstance(self.model, Eagle3LlamaForCausalLM)
target_hidden_states = self.model.combine_hidden_states(
target_hidden_states)
assert target_hidden_states.shape[-1] == self.hidden_size
# Shift the input ids by one token.
# E.g., [a1, b1, b2, c1, c2, c3] -> [b1, b2, c1, c2, c3, c3]
self.input_ids[:num_tokens - 1] = target_token_ids[1:]
# Replace the last token with the next token.
# E.g., [b1, b2, c1, c2, c3, c3] -> [a2, b2, b3, c2, c3, c4]
self.input_ids[last_token_indices] = next_token_ids
# update pcp related params
if self.pcp_size > 1 and is_prefill:
num_tokens, input_ids, target_hidden_states, max_query_len, seq_lens, cu_num_tokens = \
self._split_pcp_input(req_scheduled_tokens, num_tokens, target_hidden_states)
# graph mode padding not considered now
num_input_tokens = num_tokens
self.input_ids[:num_input_tokens].copy_(input_ids)
common_attn_metadata.prefill_context_parallel_metadata = long_seq_metadata
common_attn_metadata.num_actual_tokens = num_tokens
common_attn_metadata.max_query_len = max_query_len
common_attn_metadata.seq_lens_cpu = seq_lens.cpu()
common_attn_metadata.query_start_loc = \
cu_num_tokens[:batch_size + 1]
common_attn_metadata.query_start_loc_cpu = \
cu_num_tokens[:batch_size + 1].cpu()
assert self.runner is not None
builder = self.runner.attn_groups[0][0].get_metadata_builder()
attn_metadata_mtp = builder.build(0, common_attn_metadata,
self.runner.get_model())
attn_metadata = {}
for layer_name in self.attn_layer_name:
attn_metadata[layer_name] = attn_metadata_mtp
if self.use_aclgraph and num_tokens <= self.cudagraph_batch_sizes[-1]:
# Acl graph mode, add padding to the batch size
num_input_tokens = self.vllm_config.pad_for_cudagraph(num_tokens)
else:
# Eager mode, no padding needed
num_input_tokens = num_tokens
# copy inputs to buffer for cudagraph
self.positions[:num_tokens] = target_positions
self.hidden_states[:num_tokens] = target_hidden_states
# eager/acl piecewise mode need to update num_tokens_across_dp
(num_input_tokens, num_tokens_across_dp,
with_prefill) = self.runner._sync_metadata_across_dp(
num_input_tokens, self.runner.with_prefill)
moe_comm_type = self.runner._select_moe_comm_method(
num_input_tokens, with_prefill)
batch_descriptor = BatchDescriptor(num_tokens=num_input_tokens,
uniform_decode=False)
aclgraph_runtime_mode, batch_descriptor = \
self.runner.aclgraph_dispatcher.dispatch(batch_descriptor)
if aclgraph_runtime_mode not in [
CUDAGraphMode.PIECEWISE, CUDAGraphMode.NONE
]:
# Fallback to piecewise graph, when acl full graph is enabled
logger.debug(
"Currently the eagle proposer only supports cudagraph_mode "
f"PIECEWISE, and is forced to set graph mode from {aclgraph_runtime_mode} "
"to CUDAGraphMode.PIECEWISE")
aclgraph_runtime_mode = CUDAGraphMode.PIECEWISE
for step in range(self.num_speculative_tokens):
with set_ascend_forward_context(
attn_metadata,
self.vllm_config,
num_tokens=num_input_tokens,
with_prefill=with_prefill,
num_tokens_across_dp=num_tokens_across_dp,
reserved_mc2_mask=self.runner.reserved_mc2_mask,
moe_comm_type=moe_comm_type,
aclgraph_runtime_mode=aclgraph_runtime_mode,
batch_descriptor=batch_descriptor,
in_profile_run=self.runner.in_profile_run,
num_actual_tokens=num_tokens):
with ProfileExecuteDuration().capture_async('mtp_forward'):
model_kwargs = {}
model_kwargs["attn_metadata"] = attn_metadata
hidden_states = self.model(
input_ids=self.input_ids[:num_input_tokens],
positions=self.positions[:num_input_tokens],
hidden_states=self.hidden_states[:num_input_tokens])
num_indices = last_token_indices.shape[0]
if lmhead_tp_enable():
if not self.runner.with_prefill:
max_num_reqs_across_dp = num_input_tokens
else:
max_num_reqs_across_dp = self.vllm_config.scheduler_config.max_num_seqs
last_token_indices = nn.functional.pad(
last_token_indices,
(0, max_num_reqs_across_dp - num_indices))
sample_hidden_states = hidden_states[last_token_indices]
logits = self.model.compute_logits(sample_hidden_states)
if lmhead_tp_enable() and num_indices < logits.shape[0]:
logits = logits[:num_indices]
draft_token_ids = logits.argmax(dim=-1)
if self.num_speculative_tokens == 1:
# [batch_size, 1]
return draft_token_ids.view(-1, 1)
if step == 0:
draft_token_ids_list = [draft_token_ids]
else:
draft_token_ids_list.append(draft_token_ids)
# prepare next mtp inputs
# mtp>1: prefill skip or decode skip last loop
if with_prefill:
for _ in range(self.num_speculative_tokens - 1):
draft_token_ids_list.append(draft_token_ids)
if step == self.num_speculative_tokens - 1 or with_prefill:
break
attn_metadata_i = attn_metadata[self.attn_layer_name[0]]
if step == 0:
positions = target_positions[last_token_indices]
hidden_states = hidden_states[last_token_indices]
slot_mapping = attn_metadata_i.slot_mapping[last_token_indices]
attn_metadata_i.slot_mapping.fill_(-1)
attn_metadata_i.query_start_loc = self.arange[:batch_size + 1]
last_token_indices = self.arange[:batch_size]
if attn_metadata_i.num_decode_tokens != 0:
attn_metadata_i.num_decode_tokens = batch_size
input_ids = draft_token_ids_list[-1].int()
positions += 1
attn_metadata_i.decode.actual_seq_lengths_q = attn_metadata_i.query_start_loc[
1:batch_size + 1].tolist()
attn_metadata_i.decode.cos = builder.cos_cache[
positions].unsqueeze(1).unsqueeze(2)
attn_metadata_i.decode.sin = builder.sin_cache[
positions].unsqueeze(1).unsqueeze(2)
# NOTE(woosuk): We should handle the case where the draft model
# generates tokens beyond the max model length. Since it is complex
# to remove such requests from the batch, we keep them in the batch
# but adjust the position ids and slot mappings to avoid the
# out-of-range access during the model execution. The draft tokens
# generated with this adjustment should be ignored.
exceeds_max_model_len = positions >= self.runner.model_config.max_model_len
# Mask out the position ids that exceed the max model length.
# Otherwise, we may get out-of-range error in RoPE.
clamped_positions = torch.where(exceeds_max_model_len, 0,
positions)
# Increment the sequence lengths.
attn_metadata_i.seq_lens[:batch_size] += 1
# For the requests that exceed the max model length, we set the
# sequence length to 1 to minimize their overheads in attention.
exceeds_max_model_len_cpu = exceeds_max_model_len.to(
attn_metadata_i.seq_lens.device, non_blocking=True)
attn_metadata_i.seq_lens[:batch_size].masked_fill_(
exceeds_max_model_len_cpu, 1)
# Mask out the slot mappings that exceed the max model length.
# Otherwise, the KV cache will be inadvertently updated with the
# padding tokens.
slot_mapping += 1
slot_mapping.masked_fill_(exceeds_max_model_len, PADDING_SLOT_ID)
# copy inputs to buffer for cudagraph
self.input_ids[:batch_size] = input_ids
self.positions[:batch_size] = clamped_positions
self.hidden_states[:hidden_states.shape[0]] = hidden_states
attn_metadata_i.slot_mapping[:batch_size] = slot_mapping
if attn_metadata_i.prefill is not None:
attn_metadata_i.prefill.seq_lens = attn_metadata_i.seq_lens
attn_metadata_i.prefill.seq_lens_list = attn_metadata_i.prefill.seq_lens.tolist(
)
attn_metadata_i.prefill.context_lens = attn_metadata_i.seq_lens
attn_metadata_i.prefill.input_positions = self.positions[:
num_input_tokens]
attn_metadata_i.prefill.max_seq_lens += 1
attn_metadata_i.prefill.max_seq_lens = min(
attn_metadata_i.prefill.max_seq_lens,
self.runner.model_config.max_model_len)
if attn_metadata_i.decode is not None:
attn_metadata_i.decode.seq_lens = attn_metadata_i.seq_lens
attn_metadata_i.decode.seq_lens_list = attn_metadata_i.decode.seq_lens.tolist(
)
attn_metadata_i.decode.input_positions = self.positions[:
num_input_tokens]
attn_metadata_i.decode.max_seq_lens += 1
attn_metadata_i.decode.max_seq_lens = min(
attn_metadata_i.decode.max_seq_lens,
self.runner.model_config.max_model_len)
# mtp>1: [batch_size, k]
draft_token_ids = torch.stack(draft_token_ids_list, dim=1)
return draft_token_ids
# TODO Using torch instead of triton may result in poor performance
def _prepare_input_kernel(self, out_ptr: torch.Tensor,
cu_query_lens: torch.Tensor,
cu_num_tokens: torch.Tensor, block_size: int):
device = cu_query_lens.device
dtype = out_ptr.dtype
offsets = torch.arange(block_size, device=device, dtype=dtype)
start_pos = cu_num_tokens[:-1]
end_pos = cu_num_tokens[1:]
num_tokens = end_pos - start_pos
global_indices = (start_pos.view(-1, 1) + offsets.view(1, -1))
values = (cu_query_lens[:-1].view(-1, 1) + offsets.view(1, -1))
mask = (offsets.view(1, -1) < num_tokens.view(-1, 1))
global_indices_flat = global_indices[mask]
values_flat = values[mask]
out_ptr[global_indices_flat] = values_flat
def prepare_next_token_ids_cpu(
self,
sampled_token_ids: list[list[int]],
requests: dict[str, CachedRequestState],
gpu_input_batch: InputBatch,
num_scheduled_tokens: dict[str, int],
) -> torch.Tensor:
"""
This function is used to prepare the inputs for speculative decoding.
It calculates the next token ids for each request based on the sampled
token ids from the CPU. If a request has no sampled token ids (e.g.,
during the initial decoding steps), it falls back to using the request
state to get the next token id.
"""
req_ids = gpu_input_batch.req_ids
next_token_ids: list[int] = []
for i, token_ids in enumerate(sampled_token_ids):
if token_ids:
# Common case.
next_token_id = token_ids[-1]
else:
# Partial prefill (rare case).
# Get the next token id from the request state.
req_id = req_ids[i]
req_state = requests[req_id]
seq_len = req_state.num_computed_tokens + num_scheduled_tokens[
req_id]
next_token_id = req_state.get_token_id(seq_len)
next_token_ids.append(next_token_id)
next_token_ids = torch.tensor(next_token_ids,
dtype=torch.int32,
device=self.input_ids.device)
return next_token_ids
def prepare_next_token_ids_padded(
self,
common_attn_metadata: CommonAttentionMetadata,
sampled_token_ids: torch.Tensor,
requests: dict[str, CachedRequestState],
gpu_input_batch: InputBatch,
discard_request_indices: torch.Tensor,
num_discarded_requests: int,
) -> tuple[torch.Tensor, torch.Tensor]:
"""
This function is used to prepare the inputs for speculative decoding.
It calculates the next token ids and the number of valid sampled tokens
for each request, considering the "discarded" requests whose next token
is not sampled and comes from `request.get_token_id()` instead.
It also accounts for the rejected tokens in `sampled_token_ids`.
This function must use device functions to operate on the inputs, and
should not introduce any blocking CPU-GPU synchronization.
"""
# TODO(Ben): Combine this into a custom fused kernel
# Precompute get_token_id for when there is no valid next token
num_reqs = gpu_input_batch.num_reqs
self.backup_next_token_ids.np[:num_reqs] = np.array([
requests[gpu_input_batch.req_ids[i]].get_token_id(
common_attn_metadata.seq_lens_cpu[i].item())
for i in range(num_reqs)
])
self.backup_next_token_ids.copy_to_gpu(num_reqs)
# Mask out the sampled tokens indices that should not be sampled.
discard_sampled_tokens_req_indices = discard_request_indices[:
num_discarded_requests]
valid_sampled_token_ids_gpu = sampled_token_ids.clone()
valid_sampled_token_ids_gpu.index_fill_(
0, discard_sampled_tokens_req_indices, -1)
# Generate a mask for all valid tokens within those requests
valid_mask = (valid_sampled_token_ids_gpu != -1) & (
valid_sampled_token_ids_gpu < gpu_input_batch.vocab_size)
# Count the number of valid tokens in each request
valid_sampled_tokens_count = valid_mask.sum(dim=1)
# Get the rightmost valid index per row
last_valid_indices = valid_sampled_tokens_count - 1
last_valid_indices_safe = torch.clamp(last_valid_indices, min=0)
# Get last valid token from each row
# (assume undefined state where there is no valid token)
selected_tokens = torch.gather(
valid_sampled_token_ids_gpu, 1,
last_valid_indices_safe.unsqueeze(1)).squeeze(1)
# Use last token if valid, pre-computed backup if not
batch_size = valid_sampled_token_ids_gpu.shape[0]
next_token_ids = torch.where(
last_valid_indices != -1,
selected_tokens,
self.backup_next_token_ids.gpu[:batch_size],
)
return next_token_ids, valid_sampled_tokens_count
def prepare_inputs_padded(
self,
common_attn_metadata: CommonAttentionMetadata,
spec_decode_metadata: SpecDecodeMetadata,
valid_sampled_tokens_count: torch.Tensor,
) -> tuple[CommonAttentionMetadata, torch.Tensor, torch.Tensor]:
"""
This function is used to prepare the inputs for speculative decoding
It updates the common_attn_metadata for speculative decoding,
but does not consider the rejected tokens. Instead, all tokens
are included as inputs to the speculator, with the rejected tokens
used as padding and filtered out later by `token_indices_to_sample`.
No blocking CPU operations should be introduced in this function.
"""
num_draft_tokens_gpu = torch.cat([
spec_decode_metadata.cu_num_draft_tokens[0:1],
spec_decode_metadata.cu_num_draft_tokens[1:] -
spec_decode_metadata.cu_num_draft_tokens[:-1],
])
num_rejected_tokens_gpu = torch.where(
num_draft_tokens_gpu > 0,
num_draft_tokens_gpu + 1 - valid_sampled_tokens_count,
torch.zeros_like(num_draft_tokens_gpu),
)
query_start_loc_cpu = common_attn_metadata.query_start_loc_cpu
new_query_len_per_req = query_start_loc_cpu[
1:] - query_start_loc_cpu[:-1]
total_num_tokens = query_start_loc_cpu[-1].item()
token_indices = self.arange[:total_num_tokens]
spec_common_attn_metadata = AscendCommonAttentionMetadata(
query_start_loc=common_attn_metadata.query_start_loc,
query_start_loc_cpu=query_start_loc_cpu,
seq_lens_cpu=common_attn_metadata.seq_lens,
num_reqs=common_attn_metadata.num_reqs,
num_actual_tokens=total_num_tokens,
max_query_len=new_query_len_per_req.max().item(),
actual_seq_lengths_q=self.runner.actual_seq_lengths_q,
block_table_tensor=common_attn_metadata.block_table_tensor,
slot_mapping=common_attn_metadata.slot_mapping,
positions=common_attn_metadata.positions,
attn_mask=self.runner.attn_mask,
spec_attn_mask=self.runner.spec_attn_mask,
attn_state=self.runner.attn_state,
graph_pad_size=self.runner.graph_pad_size,
decode_token_per_req=self.runner.decode_token_per_req,
num_computed_tokens_cpu=common_attn_metadata.
num_computed_tokens_cpu,
seq_lens=common_attn_metadata.seq_lens)
token_indices_to_sample = (common_attn_metadata.query_start_loc[1:] -
1 - num_rejected_tokens_gpu)
return spec_common_attn_metadata, token_indices, token_indices_to_sample
def _split_pcp_input(self, req_scheduled_tokens, num_tokens,
target_hidden_states):
"""
Split input_ids and target_hidden_states in pcp group.
1. input_ids padding: [t0, t1, t2, t3, t4, t5] -> [t0, t1, t2, t3, t4, t5, pad, pad]
2. split input_ids: pcp0 [t0, t1, pad, pad], pcp1 [t2, t3, t4, t5]
3. split target_hidden_states (already include cp padding):
[h0, h1, h2, h3, h4, h5, pad, pad] -> pcp0 [h0, h1, pad, pad], pcp1 [h2, h3, h4, h5]
4. also update max_query_len, seq_lens, cu_num_tokens according to pcp split.
"""
def _pcp_pad_and_split(num_tokens):
num_pcp_padded_scheduled_tokens = cdiv(
num_tokens, 2 * self.pcp_size) * 2 * self.pcp_size
pcp_pad = num_pcp_padded_scheduled_tokens - num_tokens
chunk_size = num_pcp_padded_scheduled_tokens // (2 * self.pcp_size)
# split position_ids (and use split position_ids to split input_ids afterwards)
req_position_cp: list[int] = []
req_position_cp.extend(
self.full_indices[self.pcp_rank *
chunk_size:(self.pcp_rank + 1) * chunk_size])
req_position_cp.extend(
self.full_indices[num_pcp_padded_scheduled_tokens -
(self.pcp_rank + 1) *
chunk_size:num_pcp_padded_scheduled_tokens -
self.pcp_rank * chunk_size])
return req_position_cp, num_pcp_padded_scheduled_tokens, pcp_pad
num_pcp_scheduled_tokens = []
input_ids_list = self.input_ids[:num_tokens]
ori_start_index = 0
pad_start_index = 0
pcp_split_input_ids_list = []
pcp_split_hidden_states_list = []
for ori_num_tokens in req_scheduled_tokens.values():
req_position_pcp, num_pcp_padded_scheduled_tokens, num_pcp_pad = \
_pcp_pad_and_split(ori_num_tokens)
actual_num_tokens = len(req_position_pcp)
num_pcp_scheduled_tokens.append(actual_num_tokens)
pad_input_ids = F.pad(
input_ids_list[ori_start_index:ori_start_index +
ori_num_tokens], (0, num_pcp_pad))
ori_start_index += ori_num_tokens
pcp_chunk_indices = [
pad_start_index + pos for pos in req_position_pcp
]
pcp_split_input_ids = pad_input_ids[req_position_pcp]
pcp_split_hidden_states = target_hidden_states[pcp_chunk_indices]
pcp_split_input_ids_list.append(pcp_split_input_ids)
pcp_split_hidden_states_list.append(pcp_split_hidden_states)
pad_start_index += num_pcp_padded_scheduled_tokens
num_tokens = sum(num_pcp_scheduled_tokens)
input_ids = torch.cat(pcp_split_input_ids_list)
target_hidden_states = torch.cat(pcp_split_hidden_states_list, dim=0)
max_query_len = max(num_pcp_scheduled_tokens)
seq_lens = torch.tensor(num_pcp_scheduled_tokens, dtype=torch.int32)
cu_num_tokens = torch.tensor(
np.insert(np.cumsum(np.array(num_pcp_scheduled_tokens)), 0, 0))
return num_tokens, input_ids, target_hidden_states, max_query_len, seq_lens, cu_num_tokens