- Turn Scheduler into a class: only waiting/running/decode_step (bound by pybind) stay public; internals become private. - Move immutable knobs into SchedulerConfig::capture(), alongside the constructor-time checks. - Drop dead state: dp_size, dp_rank, truncate_len, schedule_counter, last_step_*, tokens_chunked_prefill_remaining, and the max_num_prompts alias. The unused truncate_len constructor argument is removed from the binding, the stub and llm_engine. - Split _schedule into _schedule_normal / _schedule_prefill / _schedule_decode; decode is further split into _admit_prompted and _select_decode_batch. - Share the forked-KV detach logic between prefill and decode (_detach_forked_cache) instead of two hand-written copies. - prompted no longer carries a tuple<seq, bool>: the flag was always true. - process_outputs: the returned buffers become per-instance members instead of function-level statics shared by all Scheduler instances. The binding returns them as zero-copy numpy arrays whose base is the Scheduler, so holding an array keeps the storage alive. - SchedulerOutputs is filled incrementally instead of via a 10-arg ctor. - Fix the LCFS comment: preemption victims are the longest-output seqs. - block_manager.hpp now includes <sys/time.h> itself for gettimeofday. Verified with a differential harness that drives the old and new Scheduler through identical randomized workloads (NORMAL/PROMPT/COMPLETION, chunked prefill, MTP varlen, forks, preemption, aborts, multimodal chunk boundaries, simulated multi-rank votes) and compares full per-step state: 120/120 traces identical on macOS/clang and Linux/GCC 15; a Python smoke test through the real pybind bindings is also identical old vs new. |
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| csrc | ||
| deep_cluster | ||
| deepinfer | ||
| doc | ||
| eval | ||
| examples | ||
| scripts | ||
| tests | ||
| vendor | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| build.sh | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| Makefile | ||
| pyproject.toml | ||
| README.md | ||
| requirements-ascend.txt | ||
| requirements-dev.txt | ||
| requirements-nvidia.txt | ||
| requirements.txt | ||
| setup.py | ||
DeepInfer
DeepInfer is the high-performance inference framework that powers DeepSeek's large-scale production services. This open-source release provides offline inference with the core features needed for serving at scale.
Supported models:
- DeepSeek-V4.1-Flash
Supported features:
- Optimized kernels, model and sampler runtime
- Parallelism: Attention DP / balanced CP, MoE EP + EPLB
- DSpark and confidence-scheduled verification
- SWA bounded replay
- Asynchronous scheduling (zero-overhead batch scheduler)
- Batch-invariant inference
- Deterministic sampling
- Structured outputs
Feature details and configuration
- Optimized kernels: FlashMLA, DeepGEMM, DeepEP, TileKernels, DeepSelect, and custom TileLang kernels.
- DSpark and confidence-scheduled verification: accelerate decoding with draft tokens and use confidence estimates to schedule verification. Set
DEEPINFER_ENABLE_MTP_VARLEN=1;DEEPINFER_USE_NEXTN_DECODEcontrols the maximum draft length (default: 5). - Decoder SWA bounded replay: reduce decoder prefill work by replaying only a bounded suffix. Set
DEEPINFER_YOCO_PREFILL_TRUNCATION_MODE=compactandDEEPINFER_YOCO_PREFILL_KEEP_TOKENS=140for the default V4.1 settings; the retained suffix must cover the SWA window plus the maximum backtracking length. - Asynchronous scheduling: overlap CPU batch scheduling with device execution. Enabled by default.
- Batch-invariant inference: keep model results identical across different batch compositions. Enable with
DEEPINFER_BATCH_INVARIANT=1(NVIDIA only). - Deterministic sampling: produce identical outputs for identical input tokens and sampling parameters. Set
DEEPINFER_BATCH_INVARIANT=1 DEEPINFER_ENABLE_MTP_VARLEN=0and pass a fixedseq_seedtoSamplingParams(NVIDIA only). - Structured outputs: constrain generation to a regex, JSON schema, or EBNF grammar. Pass
so_args={"schema_type": ..., "schema": ...}toSamplingParams; see examples.
Supported hardware:
- NVIDIA SM100 GPUs
- Huawei Ascend 950 NPUs
Required for a complete inference service (not included in this release):
- A KV cache system
- VE/Prefill/Decode disaggregation (most required engine functionality is already implemented)
- Load balancing across data-parallel replicas for both prefill and decode
Getting started
Prerequisites
- Linux
- GCC >= 13.0
- Python 3.12
- CUDA 13 (NVIDIA only)
- CANN 9.2 (Ascend only)
Build from source
Before building DeepInfer, please create and activate an empty Python 3.12 environment.
# Use `ascend` instead for the Ascend platform
# Keep it exported in the environment where you run DeepInfer
export DEEPINFER_ACCELERATOR=nvidia
./build.sh
Offline inference
The default checkpoint, deepseek-ai/DeepSeek-V4.1-Flash-1017, is
downloaded into the Hugging Face cache on the first run; set DEEPINFER_HF_MODEL_DIR=/path/to/DeepSeek-V4.1-Flash-1017 to
run from a local copy instead.
python examples/offline_inference.py
See examples for details.
Performance benchmarks
| Prefill | Decode |
|---|---|
![]() |
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Measured on 4 SM100 GPUs for prefill and 64 for decode — each within one scale-up domain. To reproduce the benchmarks, see run_sweep.sh.
Evaluation benchmarks
See eval/README.md.
License
DeepInfer is released under the Apache License 2.0. See LICENSE for details.
Acknowledgments
DeepInfer was originally built primarily on vLLM, with additional inspiration from SGLang and TensorRT-LLM. We thank their developers.
Citation
@misc{deepinfer2026,
title = {DeepInfer: High-performance, large-scale inference framework for DeepSeek models},
author = {DeepSeek-AI},
year = {2026},
publisher = {GitHub},
howpublished = {\url{https://github.com/deepseek-ai/DeepInfer}},
}

