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A comment on A Journey into the Linux Scheduler. Parent comment

Re:A Journey into the Linux Scheduler by gpderetta on Monday July 04, 2022 @01:04PM (#31979301)
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.

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Re:A Journey into the Linux Scheduler by chupasaurus on Monday July 04, 2022 @03:17PM (#31980723)
> 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

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Re:A Journey into the Linux Scheduler by PaulDavisThe1st on Monday July 04, 2022 @01:20PM (#31979529)
Correct on all counts. But there is also the difference between SCHED_FIFO and SCHED_RR to be covered.
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Re:A Journey into the Linux Scheduler by maxgio92 on Monday July 04, 2022 @02:25PM (#31980293)
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.
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