this post was submitted on 16 Feb 2024
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I use Arch btw

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Htop too (lemm.ee)
submitted 9 months ago by [email protected] to c/[email protected]
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[–] [email protected] 10 points 9 months ago* (last edited 9 months ago) (2 children)

I think a lot of modern kernels are “tickless” - they don’t use a timeslice timer, and only context switch on IO interrupt, process yield, or when timeouts are specifically requested (including capping cpu-bound processes). https://en.m.wikipedia.org/wiki/Tickless_kernel

[–] [email protected] 18 points 9 months ago (1 children)

Tickless means it’s not based on the computer frequency and idle CPUs can stay idle rather than being annoyingly brought into high power mode ever 100 Hz, but it’s still firing interrupts based on scaling timed variables.

They’re now called “Dynticks”

SUSE wrote the vaguely more understandable write up that Linux foundation links to: https://www.suse.com/c/cpu-isolation-full-dynticks-part2/

BTW, the Linux RCU code is evil but interesting: https://www.p99conf.io/session/how-to-avoid-learning-the-linux-kernel-memory-model/

[–] [email protected] 5 points 9 months ago

Fascinating stuff. Obviously a lot has changed since I took an undergrad OS class lol. Hell, Linux didn't even exist back then.