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The long road to lazy preemption in the Linux CPU scheduler

(lwn.net)
218 points chmaynard | 1 comments | 19 Oct 24 07:29 UTC | HN request time: 0.204s | source
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hamilyon2 ◴[19 Oct 24 12:32 UTC] No.41887445[source]▶
How tight is scheduler coupled to the rest of kernel code?

If one wanted to drastically simplify scheduler, for example for some scientific application which doesn't care about preemption at all, can it be done in clean, modular way? And will be any benefit?

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1. toast0 ◴[19 Oct 24 14:59 UTC] No.41888151[source]▶
You can get 95% of the way there by running a clean system with nearly no daemons, and your application setup to run with one os thread per cpu thread, with cpu pinning so they don't move.

Whatever the scheduler does should be pretty low impact, because the runlist will be very short. If your application doesn't do much I/O, you won't get many interrupts either. If you can run a tickless kernel (is that still a thing, or is it normal now?), you might not get any interrupts for large periods.