PREEMPT(9)

👑 PREEMPT(9) — Kernel Developer’s Manual energy 👑

okay so this page is literally named preempt, and it’s from the Kernel Developer’s Manual. We’re talking general preempt and yield functions, bestie. 🫶

✨ NAME ✨

preempt, yield — general preempt and yield functions

🎀 SYNOPSIS 🎀

#include <sys/sched.h>

void
preempt(void);

#include <sys/proc.h>

void
yield(void);

🌸 DESCRIPTION 🌸

So preempt() takes the current LWP and puts it back on the system run queue, then performs an involuntary context switch. That’s the whole flex. 💅

yield() is mostly the same as preempt() — the key difference is that it performs a voluntary context switch. Yes bestie, voluntary vs. involuntary is the vibe check here. ✨

Both of these functions drop the kernel lock before switching, and they re-acquire it before returning. no cap. 🔥

okay that’s the page, bestie 🫶 — source/version is Debian, the date is July 3, 2007, and the manual slot is literally PREEMPT(9). periodt 💖