stop_machine_cpuslocked(9)

💅 stop_machine_cpuslocked(9) 💅

okay so this is straight out of the Kernel API Manual, and bestie, it's a good one — it's giving "stop the world" but make it kernel ✨

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🌸 NAME 🌸

stop_machine_cpuslocked — freeze the machine on all CPUs and run this function 🧊🔥

like, all of them. every CPU. nobody moves until the function does its thing. main character function energy fr fr.

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🎀 SYNOPSIS 🎀

int stop_machine_cpuslocked (cpu_stop_fn_t fn , void *data , const
       struct cpumask *cpus );

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🦋 ARGUMENTS 🦋

• fn — the function to run 💫 like, this is the whole point, the star of the show
• data — the data ptr to pass to fn 🎁 (a little gift for your function, we love that)
• cpus — the cpus to run fn on (NULL = one unspecified online CPU) 👀 note that NULL is a real option here, and it means one unspecified online CPU, not all of them, not zero — one, and unspecified

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🧚 DESCRIPTION 🧚

Same as above. No cap, that's the whole thing — the manpage literally says "Same as above" 😭 iykyk.

Also: avoids nested calls to cpus_read_lock. That's the lock part of the name, and it's the whole reason this variant exists — nested cpus_read_lock calls? not today, bestie 🙅‍♀️

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💜 CONTEXT 💜

Must be called from within a cpus_read_lock protected region. 🔒

not optional, not a suggestion, not a vibe — it's a must. call it outside that region and you're not slaying, you're just wrong 💀

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👑 SEE ALSO 👑

• Kernel file ./include/linux/stop_machine.h
• stop_machine(9)
• stop_core_cpuslocked(9)

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that's the whole thing, bestie — you ate that 🫶 source is ./include/linux, version date October 2026, and the page signs off as stop_machine_cpuslocked(9). periodt. 🌈⭐