What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
The Linux Foundation Real-Time Linux project lists 6.12-rt, 6.6-rt, 6.1-rt, 5.15-rt, and 5.10-rt as actively maintained PREEMPT_RT lines, with 6.18-rt as the development line. The listed support endpoints are projections and the status page can change, so verify it before choosing a kernel.
Which PREEMPT_RT versions are currently maintained?
The Linux Foundation Real-Time Linux project’s version overview, accessed in 2026, lists these lines and projected support endpoints:
| PREEMPT_RT line | Status | Projected support endpoint |
|---|---|---|
| 6.18-rt | Development | Not stated |
| 6.12-rt | Actively maintained | December 2026 |
| 6.6-rt | Actively maintained | December 2026 |
| 6.1-rt | Actively maintained | December 2027 |
| 5.15-rt | Actively maintained | October 2026 |
| 5.10-rt | Actively maintained | December 2026 |
These dates are projections, not guaranteed end-of-life dates. Kernel.org cautions that projected long-term support endpoints can change. The project overview also marks 6.17-rt through 6.13-rt and several earlier patch lines as no longer maintained. Because its version table is volatile, consult the Linux Foundation Real-Time Linux version overview for the latest status rather than treating this snapshot as permanent.
Is PREEMPT_RT included in the Linux kernel?
PREEMPT_RT configuration entered the mainline Linux kernel in version 6.12 for x86, ARM64, and RISC-V, according to the Realtime Linux guide. That does not mean every kernel at or above 6.12 is configured for real-time use, nor does it make the separate RT patch queue obsolete. The queue continues development and carries additions that have not yet been merged upstream. Older kernel versions require the patch.
Do these 3 things before closing this tab:
1Fix the driver behind crashes, sound loss and screen glitches2Clear out junk files and repair common Windows errors3Scan for outdated or missing drivers - takes under a minute#1 Best Overall
PREEMPT_RT makes most kernel execution contexts more preemptible. As the Linux kernel’s real-time theory documentation explains, it uses sleeping locks with priority inheritance and moves interrupt handling into threads, while a small number of critical paths remain outside full preemption. The objective is to reduce the delay between a high-priority task becoming runnable and its execution; it is not a timing guarantee independent of hardware, workload, or configuration.
How to choose a PREEMPT_RT version
Choose a kernel that your system can actually support, rather than selecting only by version number or projected endpoint. Compare candidates on these factors:
Rank #2
- Architecture, drivers, and board support: Check that the kernel line works with your processor architecture, required drivers, and board support package.
- Distribution or vendor policy: A distribution kernel can differ from the corresponding upstream kernel.org release. Kernel.org advises distribution users to rely on their distribution’s support channels.
- Maintenance horizon: Check the PREEMPT_RT project’s current status and your vendor’s own maintenance commitments. Projected upstream endpoints do not establish how long a distribution or board vendor will support its package.
- Measured latency: Evaluate the candidate under the real application workload and against its timing requirements. A version label alone cannot establish whether latency is acceptable.
The Realtime Linux guide gives Debian’s linux-image-rt-amd64 package and Yocto’s linux-yocto-rt recipe as examples of ways to obtain or build a real-time kernel. These examples do not guarantee that a suitable package exists for every release, architecture, or vendor board.
How to check whether a Linux kernel is running PREEMPT_RT
Run the guide’s basic check in a terminal:
cat /sys/kernel/realtimeAn output of 1 indicates that the running kernel reports PREEMPT_RT. A recent kernel version by itself does not verify that the active configuration is real-time.
How to evaluate latency
The Realtime Linux guide names cyclictest and the kernel’s rtla timerlat tooling for investigating latency. Use them as measurement aids, not as proof that a system will meet every deadline. Run tests under the intended application load and on the target hardware; the relevant result is performance against that application’s timing requirements.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
