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2024-12-21 - 06:09

Dates and Events:

OSADL Articles:

2024-10-02 12:00

Linux is now an RTOS!

PREEMPT_RT is mainline - What's next?


2023-11-12 12:00

Open Source License Obligations Checklists even better now

Import the checklists to other tools, create context diffs and merged lists


2023-03-01 12:00

Embedded Linux distributions

Results of the online "wish list"


2022-01-13 12:00

Phase #3 of OSADL project on OPC UA PubSub over TSN successfully completed

Another important milestone on the way to interoperable Open Source real-time Ethernet has been reached


2021-02-09 12:00

Open Source OPC UA PubSub over TSN project phase #3 launched

Letter of Intent with call for participation is now available



2024-10-02 12:00 Age: 80 Days

Linux is now an RTOS!

By: Jan Altenberg

PREEMPT_RT is mainline - What's next?

On September 29, 2024 Linus Torvalds released kernel version 6.12-rc1 and, as usual, this new kernel comes with many useful features. This may seem like “business as usual” from the outside – for the OSADL community, however, this is not just a regular release, but an important milestone on a journey that OSADL has been supporting for almost 20 years: PREEMPT_RT real-time configuration has been included into the mainline kernel enabling real-time scheduling for x86, ARM64 and RISC-V on the unmodified original Linux kernel – Linux is now an RTOS!

The first mainline release of real-time Linux is a great achievement and we are indebted to all those who have been involved in this project over the years – as developers, maintainers, organizers and funders. This includes all OSADL members, who supported PREEMPT_RT development by being part of the community. OSADL has been part of the project since its inception, providing funding and being a long-term premium sponsor of the “Real Time Linux collaborative project” of the Linux Foundation, which has taken the lead in the project. In addition, the OSADL QA Farm provides quality assurance and continuous real-time latency measurements of Linux systems for both, developers and users, and helps bringing real-time into real-world products.

The story of real-time Linux is not just about real-time. Every step of the kernel’s journey towards real-time involved a review of every single kernel area. In this process, many bugs were fixed and features added, making Linux better for everyone as a side effect. Just to name a few of the new features: tracing infrastructure, high resolution timers and threaded interrupt handlers. Looking back at this history, the Linux kernel is much better today than it would be without the development for real-time.

While celebrating 25 years of real-time Linux and Linux becoming an RTOS we must not forget that, like anything else in Linux, PREEMPT_RT still has some open issues and needs to be continuously maintained and improved. The journey will continue on the mainline path and OSADL will remain committed. And, no surprise, the OSADL QA Farm already has a system equipped with kernel 6.12-rc1 and CONFIG_PREEMPT_RT enabled: Rack #1, slot #3