LinkedInNoteEngineering Leadership

Linux ships on a 9-week release cycle.

The first two weeks are a merge window for new features, and the next seven are only for fixing features and regressions. That cadence reduces pressure and improves maintainability.

LinkedIn
March 22, 2025
Read time
3 min
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English
Engineering LeadershipMar 22, 2025English
  1. Linux ships on a 9-week release cycle. The first 2 weeks are a merge window for new features. The following 7 weeks are only for fixing features and regression bugs. In the past, Linux had much longer development cycles, ranging from 6 months to 2-3 years, which created a lot of pressure around getting features merged.

  2. "A 9-week cycle reduces the burden on developers. If a feature isn't ready, you can just wait for the next 9 weeks. It creates an environment where maintainers don't have to force incomplete features in."

  3. The entire Linux kernel codebase is roughly 40 million lines. Only about 5% of that is the core kernel shared across all systems. The server core kernel is around 1.5 million lines, while the smartphone core kernel is around 4 million. Mobile devices are more complex because they have to interact with power management, clock control, battery management, modem communication, and many other hardware concerns.

  4. They care not only about code quality, but also about whether a contributor will keep participating in maintenance over time. Especially in core systems, a key merge question is whether this person can continue owning and caring for the code. "We all make mistakes. What matters is that there's someone who will fix them."

  5. Around 4,000 developers from roughly 500 companies contribute to Linux every year. Most of them are paid by their employers and contribute because their companies need Linux.

  6. "There's a joke that if you contribute to Linux three times, your employment is guaranteed. But it isn't really a joke."

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