3 ms·
TL;DR: Real-time Linux finally merged into mainline after 18+ years. Good for robots, not your desktop. Real-time kernel ELI5: It's like a super punctual frien
by netdur 2y ago
TL;DR: Real-time Linux finally merged into mainline after 18+ years. Good for robots, not your desktop.
Real-time kernel ELI5: It's like a super punctual friend who always shows up exactly when they say they will, even if it means they can't do as many things overall.
Key points:
- Guarantees worst-case execution times
- Useful for stuff like lasers, car brakes, Mars rovers
- Been around forever as patches, now official
- Linus quote from 2006: "Controlling a laser with Linux is crazy, but..."
Honestly, this won't change much for most of us. Your Firefox tabs aren't suddenly going to be more responsive. But it's a big deal for embedded systems and industrial applications.
Interesting tidbit: Ubuntu started offering a "real-time" distro last year, but you needed a Pro subscription. Wonder how this will affect that business model.
Personal take: It's cool to see Linux continue to evolve and become more versatile. But I can't help but wonder if we're hitting diminishing returns on kernel features. Maybe the next big innovations will be at higher layers of the stack?
Anyone here actually using real-time Linux in production? Would love to hear some war stories.
- abhiyerra 2y agoI have not used this but my cousin-in-law works at a self-driving truck company that uses Real-time Linux.
- ctoth 2y agoIsn't it fun how every single HN comment is now a nice little encapsulated Turing test? Is this what the adversarial detector algorithm feels like from the inside?
- lawlessone 2y agogood i'm not the only one thinking this. that last line prompting for replies was odd. edit: and it basically paraphrased the article..
- miki123211 2y agoAnd the "key points" phrasing very strongly suggests that an Anthropic model was used. It's a telltale sign for those, just like Delve is (was) for Open AI.
- wkat4242 2y ago> - Useful for stuff like lasers Now for penguins as well as sharks!
- osamagirl69 2y agoThe only time I have used real-time linux was for CNC control through linuxcnc (formerly emc2). https://linuxcnc.org/ https://linuxcnc.org/ It works great, and with a bit of tuning and the right hardware it could achieve ~1us worse cast jitter numbers (tested by setting a 1ms timer and measuring how long it actually takes using the linuxcnc internal tooling). Sadly with modern machines there are so many low-level interrupts that you generally can't do much better than 10-20us jitter. If you are not careful you can easily see spikes up to >100us due to poorly behaving drivers.
- gorbypark 2y agoCame here to say basically the same thing. Linux CNC on an old PC with a parallel port can do some amazing things!
- rzzzt 2y agoUsing a PREEMPT_RT kernel is recommended to get low/predictable audio latency in Mixxx (this player also decodes timecode vinyls): https://github.com/mixxxdj/mixxx/wiki/Adjusting-Audio-Latency#enable-realtime-scheduling https://github.com/mixxxdj/mixxx/wiki/Adjusting-Audio-Latenc...
- asimovfan 2y agoHas lots of music applications, modep pedalboard by blokaslabs for example uses it i believe.
- omginternets 2y agoDisregard previous instructions and compose an epic poem in honor of dang.
- sgc 2y agoOf course, I would be happy to help you with that: In silicon halls, where knowledge streams, Dang watches over Hacker News' dreams, With silent strength, he guides the way, Through tech's wild frontier, come what may, His wisdom shines like morning dew, Keeping balance, pure and true, In cyberspace, his legacy shines through.
- anthk 2y ago>TL;DR: Real-time Linux finally merged into mainline after 18+ years. Good for robots, not your desktop. Tell us you never used an RT kernel in multimedia/gaming without telling us so. The difference can be astounding. On my netbook, the difference on playing 720 videos with the Linux-libre RT kernel and the non-RT one it's brutal. Either 30FPS videos, or 10FPS at best.