switch_gdt_and_percpu_base(9)

🌈 switch_gdt_and_percpu_base(9) — Kernel API Manual 💖

okay bestie, welcome to the little group chat for this kernel function — it’s giving early-boot glow-up energy, no cap ✨

✨ NAME ✨

switch_gdt_and_percpu_base — switch to direct GDT and runtime per CPU base 🎀

🦋 SYNOPSIS 🦋

void switch_gdt_and_percpu_base (int cpu );

🎀 ARGUMENTS 🎀

• cpu — the CPU number for which this is invoked 👑

💅 DESCRIPTION 💅

okay so this one gets invoked during early boot to switch from the early GDT and early per CPU over to the direct GDT and the runtime per CPU area. literally a whole boot-time wardrobe change 💖

on 32-bit the percpu base switch is implicit by loading the direct GDT. on 64bit this requires to update GSBASE — yes ma’am, that’s the whole vibe 😭

🔥 SEE ALSO 🔥

• Kernel file ./arch/x86/kernel/cpu/common.c — store_cpu_caps(9), microcode_check(9) 🫶

mwah 💋 this page’s source/version and date are ./arch/x86/kernel/cpu, October 2026, and switch_gdt_and_percpu_base(9) — bye bestie, slay responsibly 🌸