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Live Q&A - Challenges and techniques to use Linux in Real-Time Systems
Sergio Prado - Watch Now - Duration: 27:12
I am glad you enjoyed the talk!
Yeah, RMS is one option for real-time scheduling, but I am not sure if it guarantees determinism.
Most algorithms depend on the developer to provide some input (priority, deadline, period, etc) so the algorithm can take decisions - at least until we decide to start adding AI to schedulers! :-)
Having said that, an RMS analysis can be applied to any real-time operating system (including Linux), independent of whether the kernel has an RMS scheduler or not. RMS just says you should define the priority of tasks based on their period (more frequent tasks get a higher priority), and you can do that upfront (at design time). And on Linux, you could use SCHED_FIFO or SCHED_RR to schedule those tasks.
Let me know if you have any further questions.
Thank you so much for your answer it clarifies my doubt!!!
15:39:08 From Raul Pando : Sergio, I really enjoyed your presention. I was wondering how frequently you find yourself enabling RT kernel extensions vs conventional kernel in your professional work. 15:41:22 From Ulises V : Hello Sergio, thank you for the nice presentation. Excuse me If I'm making a wrong conception here but I'm wondering why the developers of the PREEMPT_RT patch decided to implement RR, FIFO, DEADLINE but no Rate-Monotonic (RM) Algorithm for real time scheduling as far as I understand RM guarantees determinism in RTOS while DEADLINE or Earliest Deadline First does not. Thanks for your answer! 15:45:33 From Antonio : You mentioned in your presentation a wide variety of profiling and benchmarking tools for working with the Linux Kernel. Is there a particular one that you can recommend (not only for RT kernels)? Which ones do you use in your projects? 15:51:47 From Michael Kirkhart : "Be aware that some POSIX APIs were not designed with RT behavior in mind." Could you name some examples? 15:58:26 From Michael Kirkhart : RAII = Resource Allocation Is Initialization (sorry - I almost got it right): https://en.cppreference.com/w/cpp/language/raii 15:58:32 From Stephane to Sergio Prado(Direct Message) : Thanks a lot for speaking again this year! 15:58:39 From Jacob Beningo : Reacted to "RAII = Resource Allo..." with 👍 15:58:47 From Raul Pando : Thanks a lot everyone 15:58:56 From Ulises V : Reacted to "Thanks a lot everyon..." with 👍 15:58:58 From Antonio : Se ha reaccionado a "Thanks a lot every..." con ❤️
Hello Sergio, thank you for the nice presentation. Excuse me If I'm making a wrong conception here but I'm wondering why the developers of the PREEMPT_RT patch decided to implement RR, FIFO, DEADLINE but no Rate-Monotonic (RM) Algorithm for real time scheduling as far as I understand RM guarantees determinism in RTOS while DEADLINE or Earliest Deadline First does not. Thanks for your answer!