nmi_shootdown_cpus(9)

💅 NAME 💅

okay so bestie, welcome to the nmi_shootdown_cpus(9) page from the Kernel API Manual — the whole main-character mission is literally: Stop other CPUs via NMI. That’s it, that’s the vibe. No cap. ✨

🎀 SYNOPSIS 🎀

void nmi_shootdown_cpus (nmi_shootdown_cb callback );

🦋 ARGUMENTS 🦋

• callback — optional callback to be invoked from the NMI handler. If you’re passing one, this is the callback that gets invoked from the NMI handler; it’s optional, iykyk. 🫶

💜 DESCRIPTION 💜

So here’s the lore, fr fr: the NMI handler on the remote CPUs invokes callback, if it’s not NULL, first — like, callback gets the first turn. Then it disables virtualization to ensure that INIT is recognized during reboot. That’s the sequence: callback first when it’s not NULL, then virtualization goes off, all so INIT is recognized during reboot. Slay. 🌸

⚠️ one-shot alert, bestie: nmi_shootdown_cpus can only be invoked once. After the first invocation, all other CPUs are stuck in crash_nmi_callback and cannot respond to a second NMI. No round two, no double-dip, periodt. 😭💀

🌈 SEE ALSO 🌈

• Kernel file ./arch/x86/kernel/reboot.c

💌 xoxo, from the ./arch/x86/kernel source/version, dated October 2026 — your manual bestie nmi_shootdown_cpus(9) 💖✨