teardown_percpu_nmi(9)

✨ teardown_percpu_nmi(9) ✨

okay so this is a page from the Kernel API Manual, and honestly? it's a short one but it's important, so stay with me bestie 💖

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🌸 NAME 🌸

teardown_percpu_nmi — literally undoes the NMI setup of an IRQ line 🎀

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🦋 SYNOPSIS 🦋

void teardown_percpu_nmi (unsigned int irq );

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💅 ARGUMENTS 💅

• irq — the interrupt line we're pulling the CPU-local NMI configuration off of 🫶

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🔥 DESCRIPTION 🔥

So this call is the undo button for prepare_percpu_nmi — like, whatever that one set up, this one takes it right back down. no cap, that's the whole vibe ✨

⚠️ okay important: the IRQ line should not be enabled for the current CPU when you call this. and because this is a CPU-local operation, you gotta call it from non-preemptible context. like, do not be preempted mid-teardown, that's not the move 💀

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👑 SEE ALSO 👑

the kernel file ./kernel/irq/manage.c is where it lives, and here's the whole friend group — go say hi to all of them 🧚:

• synchronize_hardirq(9)
• synchronize_irq(9)
• irq_can_set_affinity(9)
• irq_can_set_affinity_usr(9)
• irq_set_thread_affinity(9)
• irq_affinity_schedule_notify_work(9)
• irq_update_affinity_desc(9)
• irq_set_affinity(9)
• irq_force_affinity(9)
• irq_set_affinity_notifier(9)
• irq_set_vcpu_affinity(9)
• disable_irq_nosync(9)
• disable_irq(9)
• disable_hardirq(9)
• disable_nmi_nosync(9)
• enable_irq(9)
• enable_nmi(9)
• irq_set_irq_wake(9)
• irq_wake_thread(9)
• free_irq(9)
• request_threaded_irq(9)
• request_any_context_irq(9)
• request_nmi(9)
• irq_percpu_is_enabled(9)
• free_percpu_irq(9)
• request_percpu_irq_affinity(9)
• request_percpu_nmi(9)
• prepare_percpu_nmi(9)
• irq_get_irqchip_state(9)
• irq_set_irqchip_state(9)
• irq_has_action(9)
• irq_check_status_bit(9)

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and that's the whole page bestie, you ate that 🍓 the source is ./kernel/irq, dated October 2026 — periodt 💜✨