---
license: other
task_categories:
- text-generation
language:
- en
tags:
- code
- kernel
- osdev
- linux
- freebsd
- openbsd
- netbsd
- rust
- systems-programming
pretty_name: KernelLLM-2
size_categories:
- 100K<n<1M
---

# KernelLLM-2 Dataset

A high-quality raw dataset for training and fine-tuning LLMs on Operating System Development, significantly expanded for the second version.

## Overview

This dataset combines raw source code from a variety of mature and hobbyist operating system kernels with thousands of expert-level technical discussions and critiques from the Linux Kernel Mailing List, plus unique Git logic-diff traces.

> [!NOTE]
> The source code included in this dataset represents the latest stable versions of the respective repositories as of **February 27th 2026**.

## Dataset Structure

The dataset is provided in **Parquet** format for optimal compression and integration with the `datasets` library.

### 1. `kernelllm_dataset_v2.parquet` (~1.8 GB)
**Unified Knowledge Base:**
- **Files/Entries:** 367,769
- **Size:** ~1.8 GB (Parquet), ~6.1 GB (Raw JSONL)
- **Sources:** 20+ Kernel and System Projects.
- **Cleaning:**
    - Preserved `SPDX-License-Identifier` and `Copyright` lines while removing generic licensing boilerplate headers to prioritize logic.
    - Exact and "smart" deduplication across repositories.
    - Excluded files < 100 characters to remove boilerplate headers.

#### Repository Distribution:
| Repository | Entry Count |
|------------|------------|
| NetBSD | 83,959 |
| Linux | 69,197 |
| FreeBSD | 50,127 |
| OpenBSD | 27,522 |
| illumos | 24,703 |
| Zephyr  | 19,066 |
| ReactOS | 17,688 |
| Haiku | 15,472 |
| U-Boot | 12,674 |
| Coreboot | 12,082 |
| SerenityOS | 9,159 |
| QEMU | 7,029 |
| EDK2 | 5,869 |
| Xen Hypervisor | 2,311 |
| musl libc | 1,875 |
| GRUB | 1,706 |
| Asterinas | 1,417 |
| seL4 | 641 |
| Limine | 151 |
| Redox OS | 34 |

### 2. Specialized Data Types
- **`git_logdiff`:** (234 entries) Pairs commit messages with filtered logic-diffs to show how code evolves.
- **`lkml_critique`:** (~26,600 pairs) Contentious technical discussions pairing code snippets with maintainer feedback.

### 3. Dataset Schema

The unified dataset contains three primary data types, each with a specific schema:

#### Source Code (`data_type: "source"`)
```json
{
  "data_type": "source",
  "source": "repository_name",
  "filepath": "relative/path/to/file.c",
  "code": "cleaned_source_code_content"
}
```

#### Git Commit Diffs (`data_type: "git_logdiff"`)
```json
{
  "data_type": "git_logdiff",
  "commit": "commit_sha_hash",
  "source": "repository_name",
  "message": "commit_message",
  "code": "git_diff_output"
}
```

#### LKML Critiques (`data_type: "lkml_critique"`)
```json
{
  "data_type": "lkml_critique",
  "source": "mailing_list_name",
  "subject": "[PATCH] subject_line",
  "code": "patch_content",
  "critique": "maintainer_feedback",
  "metadata": {
    "author": "reviewer_email",
    "date": "email_date",
    "thread_id": "thread_identifier",
    "is_openbsd": boolean
  }
}
```

#### Data Processing Features
- **Deduplication:** Content-based hashing with normalized whitespace
- **License Header Cleaning:** Preserves SPDX identifiers and copyright lines while removing generic boilerplate
- **Size Filtering:** Excludes files under 100 characters
- **Git-specific:** Deduplicates by commit SHA when available
- **Critique-specific:** Deduplicates based on code + critique content pairs

## Dataset Release Strategy 

This is the **Raw** version of the dataset. It is intended for:
1.  **Intermediate Training:** Pre-training on high-quality systems code.
2.  **Fine-Tuning:** Instruction-tuning models to act as "Kernel Maintainers".
3.  **Research:** Analyzing developer communication patterns in low-level systems.

## Licensing and Usage

This dataset is a collection of publicly available open-source code and mailing list archives. It contains content governed by multiple licenses. For full details, see the [LICENSE](LICENSE) file.

*   **GNU General Public License (GPL) v2/v3** (Linux, seL4, Xen, QEMU, coreboot, GRUB, U-Boot, ReactOS)
*   **Common Development and Distribution License (CDDL)** (illumos)
*   **BSD 2-Clause / 3-Clause / 4-Clause & ISC** (FreeBSD, NetBSD, OpenBSD, SerenityOS, Limine)
*   **MIT License** (Redox, Haiku, musl)
*   **Apache License 2.0** (Zephyr)
*   **Mozilla Public License (MPL) 2.0** (Asterinas)
*   **BSD-2-Clause-Patent** (EDK2)

### Disclaimer

1.  **Original Licenses Apply:** The individual source code files and mailing list archives contained in this dataset remain governed by their original respective licenses. 
2.  **Attribution:** The `source` and `author` fields (where available) facilitate attribution.
3.  **Research & Ethics:** This dataset is provided primarily for research and educational purposes in the field of LLM training and systems programming analysis.
4.  **License Compliance:** Users of this dataset are responsible for ensuring that their use of the data complies with all applicable licenses.

### Opt-out

If you are a maintainer of one of the included repositories and would like your data removed from future versions of this dataset, please open an issue on the Hugging Face dataset page.