topology_hotunplug_apic(9)

💅 topology_hotunplug_apic(9) — from the Kernel API Manual, bestie

okay so picture this: we're in topology_hotunplug_apic(9) and the vibe is unregistering. This is the Kernel API Manual page, and it's lowkey a short one but it ate. ✨

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🌸 NAME 🌸

topology_hotunplug_apic — remove a physical hotplugged APIC after boot 🫶

like, after boot. not during. the boot already happened. we're doing cleanup now, bestie.

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🦋 SYNOPSIS 🦋

void topology_hotunplug_apic (unsigned int cpu );

that's it. one function, one argument, returns void (so it gives you nothing back, emotionally or otherwise 💀). the way it just takes a cpu and dips.

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🎀 ARGUMENTS 🎀

• cpu — the CPU number for which the APIC ID is removed. yep, that's the whole thing. you hand it a CPU number, and the APIC ID for that CPU gets removed. no cap. 💅

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⭐ SEE ALSO ⭐

heads up, all of these live in the kernel file ./arch/x86/kernel/cpu/topology.c — go read the source, it's giving main character energy:

• topology_register_apic(9)
• topology_register_boot_apic(9)
• topology_get_logical_id(9)
• topology_unit_count(9)
• topology_hotplug_apic(9)
• topology_apply_cmdline_limits_early(9)

the whole topology friend group fr fr 🌈

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💖 friendly reminder: this is the hotunplug one. topology_hotplug_apic(9) is the plug-in side. don't mix them up, i'm begging 😭

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and that's the page!! mwah 🍓 this cutie lives under ./arch/x86/kernel/cpu, and the manual's dated October 2026 — so yeah, future vibes only. periodt. 👑✨