Hacker News new | ask | show | jobs
by gpderetta 1453 days ago
My understanding is that they don't. Realtime tasks have strict priority over non realtime tasks. As long as there are runnable rt task the kernel won't schedule any other task.

At least that's the theory. I think these days the kernel reserves (optionally?) 5% cpu to non rt tasks, enough to run a shell and kill a runaway rt process.

2 comments

> I think these days the kernel reserves (optionally?) 5% cpu to non rt tasks

That is the default setting (documentation [0]).

[0] https://docs.kernel.org/scheduler/sched-rt-group.html

Correct on all counts. But there is also the difference between SCHED_FIFO and SCHED_RR to be covered.
Yes, you're right. I preferred to not cover too much topics on the same blog, but that's a good idea as other people said here. Thank you.