Questions tagged [real-time]
For questions about real-time computing and how to achieve a certain level of guaranteed response time with UNIX or Linux systems like RTLinux. For real-time clocks (RTC) use the /clock tag instead.
166 questions
4 votes
1 answer
133 views
How do real time scheduling policies work with Intel's hybrid architecture?
I have an application with several CPU intensive threads set to the SCHED_RR scheduling policy. I recently starting running this on a system with a hybrid core Intel CPU, and noticed that these ...
1 vote
1 answer
126 views
How does a vanilla Linux kernel handle realtime scheduling?
I have a question regarding "Realtime" support in Linux/Ubuntu: After some reasearch onthe topic, it seems that "realtime" support in Linux is twofold: On the one hand, there is ...
- 13
1 vote
1 answer
222 views
Real-Time process vs Process Affinity
From my understanding a real-time process means the process will get the CPU as soon as it needs it. The kernel is responsible for this task with its internal scheduling mechanism. On the other hand, ...
- 13
1 vote
0 answers
306 views
How can I pre-fault and lock memory pages that are mmap'd with MAP_PRIVATE?
I am writing a real-time linux application where I need to prevent any page faults from occuring after the initial startup of my application. My initial thought was just to call mlockall(MCL_CURRENT | ...
- 61
0 votes
0 answers
445 views
Debugging RCU stalls on Ubuntu Server 22.04, 5.15-realtime
I am trying to isolate CPUs on an AMD EPYC 8534PN (64C/128T). Unfortunately, I see the RCU stalls and the server crashes over and over. And I am not really sure what I am doing wrong. The crashes only ...
- 1
1 vote
1 answer
138 views
How does Kernel Clock Rate matter in network emulation (by netem)?
I want to use network emulation (netem) on a PREEMPT-RT kernel to emulate latency and jitter down to 0.5 ms +- 10 %. Thus, I initially thought that I have to adapt the internal kernel clock rate to at ...
- 13
3 votes
1 answer
318 views
is there a sleep command that works with real date time and ignores suspend?
is there a sleep command that works with real date time and ignores suspend? echo a;sleep 3600;echo b i work 10mins, suspend the notebook for 2h. When I wake it up from suspend, "b" will ...
- 101
0 votes
1 answer
522 views
To create a Linux RT real-time system, which functions in the kernel should be cropped out?
I am customizing a Linux real-time system using the Linux 6.4.0 kernel and patch-6.4.6-rt8 patch. When running make menuconfig, which configurations should be turned off to improve real-time ...
- 135