The references were importable and numerically validated, but nothing pointed the model at them: the forward pass still called the compiled kernels, which raise ModuleNotFoundError on a host without TileLang. This adds the routing layer and swaps the call sites. `deepinfer/tk_compat/` exposes the *compiled* signatures -- out-buffers, in-place conventions, argument order -- because that is what the 25 call sites are written against, and adapts to the reference's shape internally. Selection is `DEEPINFER_KERNELS=auto|cuda|ref`; `auto` follows whether TileLang imports. The adapters are not pass-throughs. Each difference was found by running both backends: * `per_token_cast` takes `num_per_channels=n`, the reference takes `block_size=(1, n)`. * `apply_rotary` takes a concatenated cos|sin cache and rotates in place returning None; the reference takes cos and sin separately and returns a new tensor. The adapter splits, calls, and copies back, because the call site relies on the in-place contract. * `engram_gate` takes the pre-multiplied weight and `(eps, clamp_value)`; the reference needs the two weights separately and `(clamp_value, eps)`. Since a product cannot be un-multiplied, `fused_weight` returns the pair on the reference path and the gate unpacks it. * `mhc_pre_big_fuse_fwd` has no single reference: its five steps are composed from the reference's own components. * `mhc_reduce_partials_and_rmsnorm_fwd` likewise; rebuilt from the reference's formula. `moe_topk_gate(force_random=...)` raises rather than silently ignoring the flag. The reference has no equivalent, and dropping it would route tokens differently while looking healthy. Verification, all on the real call signatures: 18 cases compared between `cuda` and `ref` modes, `ALL_MATCH`, 12 bitwise identical including every quantised byte and every routing index; plus a smoke run that executes all 23 APIs with TileLang blocked, `ALL_CALLS_OK`. End to end still has not completed, and the reason is not this change: six GPUs on the host are held by other containers (82 GiB of 139 each), so the 8-way EP run OOMs in allocate_userbuffer and the surviving ranks wait at a barrier. Recorded in the doc along with the command to rerun it. |
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| csrc | ||
| deep_cluster | ||
| deepinfer | ||
| doc | ||
| eval | ||
| examples | ||
| scripts | ||
| tests | ||
| vendor | ||
| .clang-format | ||
| .gitignore | ||
| .gitmodules | ||
| build.sh | ||
| CONTRIBUTING.md | ||
| H20-DEBUG-PLAN.md | ||
| H20-DRIFT-ANALYSIS.md | ||
| H20-PORTING-JOURNAL.md | ||
| H20-SM90-FINDINGS.md | ||
| H20-TRITON-PLAN.md | ||
| LICENSE | ||
| Makefile | ||
| pyproject.toml | ||
| README.md | ||
| requirements-ascend.txt | ||
| requirements-dev.txt | ||
| requirements-nvidia.txt | ||
| requirements.txt | ||
| setup.py | ||
| TODO.md | ||
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}},
}

