init_per_cpu(9)

🎀 init_per_cpu(9) 🎀

okay bestie, welcome to the Kernel API Manual — today's page is init_per_cpu(9), and it's literally giving "every CPU gets its own little glow-up" energy. no cap. 💖✨

🌸 NAME 🌸

init_per_cpu — Handle individual processor initializations.

🦋 SYNOPSIS 🦋

int init_per_cpu (int cpunum );

🎀 ARGUMENTS 🎀

• cpunum — logical processor number. that's the arg, bestie. 🫶

💅 DESCRIPTION 💅

okay so this function handles initialization for every CPU in the system. not a vibe check for one CPU — every CPU. periodt. 👑

Here's the whole checklist, and yes we're keeping every single detail:

• Set "default" CPU width for trap handlers. 🎀
• Enable FP coprocessor. REVISIT: this could be done in the "code 22" trap handler. (frowands idea — that way we know which processes need FP registers saved on the interrupt stack.) NEWS FLASH: wide kernels need FP coprocessor enabled to handle formatted printing of lx for example (double divides I think). 🫶
• Enable CPU profiling hooks. slay. 🔥

👑 SEE ALSO 👑

Kernel file ./arch/parisc/kernel/processor.c, plus init_percpu_prof(9), processor_probe(9), collect_boot_cpu_data(9), and processor_init(9). iykyk — those are the next reads, bestie. 🌈

signed off with source/version ./arch/parisc/kernel and date October 2026 — init_per_cpu(9) out here with main character energy. 💅🫶