#preempt_rt — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #preempt_rt, aggregated by home.social.
-
A year ago I was experimenting with Debian netinst and live-build, trying to understand boot, init, and live systems.
Today BashCore is a set of minimalist Debian-based live ISOs (CLI/GUI, optional PREEMPT_RT).
In 2026 the focus shifts to Buildroot: reproducible systems, RT Linux, and minimal OS design for real workloads.
Happy New Year to everyone!
#Linux #Buildroot #Debian #PREEMPT_RT #RealTimeLinux #Embedded
-
🚀 Rock-solid Real-Time performance on Raspberry Pi 4!
Just stress-tested via SSH a custom #Buildroot (Kernel 6.12.61-v8 #PREEMPT_RT). Even with a massive memory hog running (stress-ng --vm 2 --vm-bytes 1G), the results are insane:
🔹 Avg Latency: 14µs
🔹 Max Latency: 42µs
🔹 Jitter: Virtually zeroThis #RPi4 is now a deterministic beast. 🐧🛠️ 64-bit RT Linux at its best!
#Linux #RealTime #EmbeddedLinux #RaspberryPi #Kernel #Performance #SystemStability
-
Built a custom Raspberry Pi 4 RT OS using Buildroot.
Manually downloaded the Raspberry kernel (6.12.61) and PREEMPT_RT patch (6.12.57), applied locally and produced a bootable SD.
It works.
No GUI, CLI tools only, deterministic boot and real-time behavior.
Learning by doing 🤓
#Linux #Buildroot #RaspberryPi #PREEMPT_RT #RealTime #Embedded #NoGUI #CLI #Nerd
-
Запуск приложений в Linux c использованием политик планирования «реального» времени
В октябре 2025 года в Нижнем Новгороде на форуме "Промышленная автоматизация: переход на открытую АСУ ТП" с коллегами зашел интересный разговор о Linux с патчем реального времени. В разговоре затронули разные интересные моменты: работа через гипервизоры, выделения ядер и отличия от QNX. Договорились о том, что я напишу небольшой гайд, рассказывающий что и как можно сделать, чтобы оптимизировать время отклика. Отдельно отмечу, что задачу доказать, что Linux с патчем PREEMPT_RT является операционной системой жёсткого реального времени перед собой не ставлю. На мой взгляд, она такой не является, так сказать by designe, в отличие от тех же QNX , VxWorks и ThreadX.
-
Halfway point (24h) in the Atom N450 Real-Time endurance test! The tiny netbook is stable and deterministic under 100% CPU load.
Key Results:
✅ System stability confirmed (0.0% CPU usage for kworkers/rcu).
⏱️ Max Jitter remains extremely low after 20 hours: 174μs (microseconds).
This proves the PREEMPT_RT kernel is effectively managing the worst-case scenario!
-
Endurance test on a 2009 Atom N450 netbook! 🛠️
This Acer Aspire One always failed on standard Linux due to a frustrating #kworker CPU spike, making it unusable. We're challenging that with #BashCoreZ_RT for 48 hours.
Goal: Prove our extreme #PREEMPT_RT optimization can permanently eliminate this hardware bug and revive the PC. Superior software rescues vintage hardware. Wish us stability! 🤞
#LinuxRT #KworkerFix #VintageTech #LowLatency -
The **BashCoreZ RT** supremacy continues! We just tamed a 2009 Intel Atom N450 netbook (2GB RAM).
MAX Jitter hit an impressive **112µs** (-t1). The difference when scaling to 16 threads (-t16) was only 42µs!
This confirms it: our zero-bloat #PREEMPT_RT architecture minimizes scheduling overhead on even the weakest legacy CPUs.
We're bringing guaranteed #RealTime performance to obsolete hardware. BashCoreZ RT makes ancient PCs viable again. Zero excuses. 👑
-
Checkmate. The final #BashCoreZ #PREEMPT_RT test is in:
On a budget 2-core Celeron N4500 laptop (250€), Max Jitter hit an insane **39µs** after isolating network noise!
This proves it: Hardware specs count for little. The clean, zero-bloat kernel is EVERYTHING. We're delivering near Hard Real-Time performance with minimal cost.
29µs on i7 vs. 39µs on Celeron? The difference is negligible. BashCoreZ RT is the definitive, free Real-Time solution. 👑
-
We didn't just win; we dominated. The ultimate #BashCoreZ #PREEMPT_RT test results are here.
On a clean, budget MSI i7 laptop (500€!), Max Jitter hit an insane **29µs**! That's the true potential of our "zero bloat" kernel 6.12 base.
(Context: Our previous "worst-case scenario" test, with some apps running, capped at only 239µs. Competitors struggle to hit that clean!)
BashCoreZ delivers Hard Real-Time performance without the huge price tag. Get building. 👊🏻
-
BashCoreZ just proved it's the ultimate Real-Time base! 🚀
Tested the ultra-minimal #BashCoreZ (Debian 13 + Kernel 6.12 #PREEMPT_RT) using #cyclictest, remotely piloted from a #BashLabOS host.
Result: Max Jitter stayed under 240µs! That’s incredible determinism for embedded, robotics, and industrial control.
The "zero bloat" foundation truly eliminates noise.
-
https://www.hdblog.it/linux/articoli/n599944/linus-torvalds-kernel-linux/
Una delle novità principali del Kernel Linux 6.12 è l'integrazione del supporto #PREEMPT_RT una funzionalità che migliora notevolmente le prestazioni ...
#UnoLinux -
2/ Side note for users of #Fedora #Linux:
#LinuxKernel 6.12 is now available for all Fedora releases in the "stable" #copr of my #kernel vanilla repositories.
For install instructions, see https://copr.fedorainfracloud.org/coprs/g/kernel-vanilla/stable/ and https://fedoraproject.org/wiki/Kernel_Vanilla_Repositories
In addition to the regular kernel package that copr as of today started shipping a dedicated #realtime kernel which has #PREEMPT_RT enabled. Install it by running:
$ sudo dnf install kernel-rt
-
2/ #realtime / -rt / #PREEMPT_RT #kernel packages for #Linux-next are now available as well: https://copr.fedorainfracloud.org/coprs/g/kernel-vanilla/next/build/8149928/
Side note: instead of 2 to 3 hours the daily builds now take 3 to 6. 😕
But whatever. 😀
-
🥳 My #kernel vanilla repositories for #Fedora #Linux[1] started shipping[2] kernels with #realtime aka #PREEMPT_RT support. 🥳
[1] https://fedoraproject.org/wiki/Kernel_Vanilla_Repositories
[2] 6.12-pre and later only obviously, as the latest stable series does not support it out-of-the-box -
リアルタイムLinuxをあきらめない ―20年越しでメインラインに統合されたPREEMPT_RTの物語
https://gihyo.jp/article/2024/10/daily-linux-241016?utm_source=feed -
With the new #PREEMPT_RT #linux kernel hitting mainline I wrote an article on the importance of kernel parameter tuning to reduce latency and jitter for #LinuxCNC
https://dantalion.nl/2024/09/29/linuxcnc-latency-jitter-kernel-parameter-tuning.html
-
#Linux v6.12-rc1-rt1 is out:
https://lore.kernel.org/all/2024093015[email protected]/
If you wonder what's still in the RT-Tree now that #PREEMPT_RT support is upstream, checkout https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/log/?h=linux-6.12.y-rt
In short: about 40 patches that among others switch 8250 to nbcon console, add support for ARM and PowerPC, or fix some drivers (like i915).
-
#Linux 6.12-rc1 is out:
https://lore.kernel.org/lkml/CAHk-=wiw[email protected]/
'"Despite conference travel (both for me and several maintainers), things seemed to go mostly fairly normally. There's a couple of notable new features in here: For one thing, #PREEMPT_RT is now mainlined and enabled as a config option (you do need to enable "EXPERT" to get the question). For another, #sched_ext also got merged.
[…]
Let's get the testing and calming down period started, ok?
Linus"'
-
Linux 的 RT (Real-Time) 版本 PREEMPT_RT
在 Hacker News Daily 上看到的，Linux kernel 把 PREEMPT_RT 這個 RT patch 併入 official repository 了：「Real-time Linux is officially part of the kernel after decades of debate」。
這類需求可以在 RTOS 裡面看到完整的說明，大家常用的特性是確保反應時間這點，像是對汽車自動
#Computer #Linux #Murmuring #OS #Software #atomic #kernel #linux #output #patch #preempt_rt #printk #realtime #realtime
-
Party! 🥳
Gratulation an alle alle, die auf die ein oder andere Weise mitgeholfen haben!
-
2/ It's done! 🥳
A few minutes ago #PREEMPT_RT (aka: #realtime support) support landed in #Linux mainline, as Linus honored the PR that Tglx handed him yesterday in person (see first toot in thread): https://git.kernel.org/torvalds/c/baeb9a7d8b60b021d907127509c44507539c15e5
Congrats and thx to everyone who was involved in this 20 year long journey!
-
The #Linux 6.12 pull request for #PREEMPT_RT is handed to Linus. Likely the first PR ever submitted in printed form. #kernel #LinuxKernel #Realtime
-
#PREEMPT_RT aka the #realtime support for #LinuxKernel hit #linux-next today! 🥳 👏
https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/log/?qt=grep&q=PREEMPT_RT
Still remains to be seen if those changes really makes it upstream during the 6.12 merge window and stick:
* It afaics is still unclear if some #printk prerequisites will be submitted for 6.12: https://lore.kernel.org/all/87ed5za2oj[email protected]/
* Troublemaking changes sometimes are reverted before the final, which in fact happened to some of printk prerequisites a while ago: https://lore.kernel.org/lkml/202206231[email protected]/
-
#Linux #kernel patches to allow enabling #PREEMPT_RT (aka proper #realtime support) for x86, ARM64, and Risc-V were posted for review:
https://lore.kernel.org/lkml/202409061[email protected]/
"The printk bits required for PREEMPT_RT are sitting in linux-next. This was the last known roadblock for PREEMPT_RT. The RT queue has additionally the "atomic console" for the 8250 UART which is not yet in linux-next.[…]"
See also these earlier other related toots:
https://fosstodon.org/@kernellogger/113084762433941141
https://fosstodon.org/@kernellogger/113085326251565367 -
v6 of the patch-set "add threaded printing + the rest" which "provides the remaining pieces of the #printk rework."[1] is now in #Linux-next – but as of now it's not yet clear if this will be merged for #kernel 6.12.
https://lore.kernel.org/all/ZthvGoJE26[email protected]/
[1] e.g. the last big missing piece for #Realtime support through #PREEMPT_RT in the mainline #LinuxKernel. But note, this series does *not* provide an nbcon console driver. That will come in a follow-up series.
-
John posted v4 of the patch-set "threaded console printing as well as some other minor pieces" which "provides the remaining pieces of the #printk rework." -- e.g. the last big missing piece for #Realtime support through #PREEMPT_RT in the mainline #Linux #Kernel. But note, "this series does *not* provide an nbcon console driver. That will come in a follow-up series."
https://lore.kernel.org/all/2024082704[email protected]/
This comes hot on the heels of the "write_atomic() printing" entering -next: https://fosstodon.org/@kernellogger/113003819326920850
-
The improved #printk series "wire up write_atomic() printing" is now in -next again and thus slated for inclusion in #Linux 6.12. This is one of the last important bits for proper #REALTIME support with #PREEMPT_RT in mainline – but not the last, as this series does not include threaded printing or nbcon drivers, as those will come later: https://lore.kernel.org/all/ZsWxpVG8uZ[email protected]/
A earlier version of the patch set was supposed to go into #kernel 6.11, but Linus was unhappy: https://lore.kernel.org/lkml/CAHk-=whU[email protected]/
-
Linus did not pull the latest printk changes for #Linux 6.11, as he did not like the what some of the changes required for proper #Realtime aka #PREEMPT_RT support do:
https://lore.kernel.org/all/CAHk-%3Dwh%[email protected]/
"'
> The messages are flushed at the end of the emergency section to allow storing the full log (backtrace) first.What? No.
One of the historically problematic situations is when a recursive oops or a deadlock occurs *during* the first oops.
[…]
'" #kernel #LinuxKernel