Files
sglang/python/sglang/srt/speculative/eagle_worker.py
2025-01-20 20:27:38 -08:00

184 lines
7.6 KiB
Python

from typing import List, Optional, Union
import torch
from sglang.srt.layers.logits_processor import LogitsProcessorOutput
from sglang.srt.managers.schedule_batch import Req, ScheduleBatch
from sglang.srt.managers.tp_worker import TpModelWorker
from sglang.srt.model_executor.forward_batch_info import (
CaptureHiddenMode,
ForwardBatch,
ForwardMode,
)
from sglang.srt.model_executor.model_runner import ModelRunner
from sglang.srt.server_args import ServerArgs
from sglang.srt.speculative.eagle_utils import EAGLEDraftInput
from sglang.srt.utils import rank0_print
class EAGLEWorker(TpModelWorker):
def __init__(
self,
server_args: ServerArgs,
gpu_id: int,
tp_rank: int,
dp_rank: Optional[int],
nccl_port: int,
target_worker: TpModelWorker,
):
# Do not capture cuda graph in `super().__init__()`
# We will capture it later
backup_disable_cuda_graph = server_args.disable_cuda_graph
server_args.disable_cuda_graph = True
super().__init__(
gpu_id=gpu_id,
tp_rank=tp_rank,
server_args=server_args,
nccl_port=nccl_port,
dp_rank=dp_rank,
is_draft_worker=True,
)
self.target_worker = target_worker
self.server_args = server_args
self.finish_extend_len = []
# Share the embedding and lm_head
embed, head = self.target_worker.model_runner.model.get_embed_and_head()
self.model_runner.model.set_embed_and_head(embed, head)
self.model_runner.server_args.disable_cuda_graph = backup_disable_cuda_graph
self.model_runner.init_cuda_graphs()
def forward_draft_decode(self, batch: ScheduleBatch):
batch.spec_info.prepare_for_decode(batch)
batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
model_worker_batch = batch.get_model_worker_batch()
forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
logits_output = self.model_runner.forward(forward_batch)
self.capture_for_decode(logits_output, forward_batch)
def forward_draft_extend(self, batch: ScheduleBatch):
self._set_mem_pool(batch, self.model_runner)
batch.spec_info.prepare_for_extend(batch)
batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
model_worker_batch = batch.get_model_worker_batch()
forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
logits_output = self.model_runner.forward(forward_batch)
self.capture_for_decode(logits_output, forward_batch)
self._set_mem_pool(batch, self.target_worker.model_runner)
def forward_batch_speculative_generation(self, batch: ScheduleBatch):
if batch.forward_mode.is_decode():
# Draft
self._set_mem_pool(batch, self.model_runner)
for i in range(self.server_args.speculative_num_steps):
self.forward_draft_decode(batch)
batch.spec_info.clear_draft_cache(batch)
self._set_mem_pool(batch, self.target_worker.model_runner)
# Verify
(
next_draft_input,
logits_output,
verified_id,
self.finish_extend_len,
accept_length_cpu,
model_worker_batch,
) = self.verify(batch)
next_draft_input.load_server_args(self.server_args)
batch.spec_info = next_draft_input
# if it is None, means all requsets are finished
if batch.spec_info.verified_id is not None:
self.forward_draft_extend_after_decode(batch)
return (
logits_output,
verified_id,
model_worker_batch,
sum(accept_length_cpu),
)
else:
# Forward with the target model and get hidden states.
# We need the full hidden states to prefill the KV cache of the draft model.
model_worker_batch = batch.get_model_worker_batch()
model_worker_batch.capture_hidden_mode = CaptureHiddenMode.FULL
logits_output, next_token_ids = self.target_worker.forward_batch_generation(
model_worker_batch
)
# Forward with the draft model.
spec_info = EAGLEDraftInput()
spec_info.load_server_args(self.server_args)
spec_info.hidden_states = logits_output.hidden_states
spec_info.verified_id = next_token_ids
batch.spec_info = spec_info
self.forward_draft_extend(batch)
return logits_output, next_token_ids, model_worker_batch, 0
def verify(self, batch: ScheduleBatch):
verify_input = batch.spec_info.prepare_for_verify(batch)
verify_input.prepare_for_verify(batch)
batch.forward_mode = ForwardMode.TARGET_VERIFY
batch.spec_info = verify_input
batch.spec_info.capture_hidden_mode = CaptureHiddenMode.FULL
model_worker_batch = batch.get_model_worker_batch()
logits_output, _ = self.target_worker.forward_batch_generation(
model_worker_batch, skip_sample=True
)
verify_input.hidden_states = logits_output.hidden_states
res = verify_input.verify(batch, logits_output)
batch.forward_mode = ForwardMode.DECODE
return res + (model_worker_batch,)
def _set_mem_pool(self, batch: ScheduleBatch, runner: ModelRunner):
batch.token_to_kv_pool = runner.token_to_kv_pool
batch.req_to_token_pool = runner.req_to_token_pool
def forward_draft_extend_after_decode(self, batch: ScheduleBatch):
seq_lens_backup = batch.seq_lens
self._set_mem_pool(batch, self.model_runner)
batch.forward_mode = ForwardMode.DRAFT_EXTEND
batch.spec_info.prepare_extend_after_decode(batch)
batch.spec_info.capture_hidden_mode = CaptureHiddenMode.LAST
model_worker_batch = batch.get_model_worker_batch()
forward_batch = ForwardBatch.init_new(model_worker_batch, self.model_runner)
logits_output = self.model_runner.forward(forward_batch)
self.capture_for_decode(logits_output, forward_batch)
self._set_mem_pool(batch, self.target_worker.model_runner)
# Restore backup.
# This is because `seq_lens` can be modified in `prepare_extend_after_decode`
batch.forward_mode = ForwardMode.DECODE
batch.seq_lens = seq_lens_backup
def capture_for_decode(
self, logits_output: LogitsProcessorOutput, forward_batch: ForwardBatch
):
sample_output = torch.softmax(
logits_output.next_token_logits, dim=-1
) # TODO(kavioyu): Support more sampling methods
spec_info = forward_batch.spec_info
spec_info.sample_output = sample_output
spec_info.hidden_states = logits_output.hidden_states
spec_info.prev_mode = forward_batch.forward_mode
# Don't support prefix share now.
def finish_request(self, reqs: Union[Req, List[Req]]):
if not isinstance(reqs, List):
reqs = [reqs]
for req in reqs:
if req.rid not in self.finish_extend_len:
continue
req_len = (
len(req.origin_input_ids)
+ len(req.output_ids)
- self.finish_extend_len[req.rid]
- 1
)
kv_indices = self.model_runner.req_to_token_pool.req_to_token[
req.req_pool_idx
][:req_len]
self.model_runner.token_to_kv_pool.free(kv_indices)
self.model_runner.req_to_token_pool.free(req.req_pool_idx)