smp_call_function(9)

💅 smp_call_function(9) — like, the Kernel API Manual, bestie ✨

okay so this is smp_call_function from the kernel API manual and honestly? it's kind of a baddie. it runs your function on all the other CPUs. no cap. 🫶

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✨ NAME ✨

smp_call_function — run a function on all the other CPUs 💖

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🌸 SYNOPSIS 🌸

void smp_call_function (smp_call_func_t func , void *info , int wait );

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🎀 ARGUMENTS 🎀

• func — the function you want to run. and like, it must be fast and non-blocking, okay? this is not the vibe for your long dramatic main-character computation 😭
• info — literally just an arbitrary pointer that gets passed through to the function. do whatever with it, queen 🦋
• wait — if true, wait (atomically!) until the function has completed on the other CPUs. atomically is doing a lot of work in that sentence ngl 💅

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🔥 DESCRIPTION 🔥

So if wait is true, then it returns once func has returned. otherwise it returns just before the target cpu calls func — the way that timing works is so specific, iykyk ⭐

big warning energy: you must not call this function with disabled interrupts, or from a hardware interrupt handler, or from a bottom half handler. like, don't. seriously. 🙈

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🌈 SEE ALSO 🌈

Kernel file ./kernel/smp.c and honestly the whole friend group:

• csd_lock_is_stuck(9)
• generic_smp_call_function_single_interrupt(9)
• __flush_smp_call_function_queue(9)
• flush_smp_call_function_queue(9)
• smp_call_function_single(9)
• smp_call_function_single_async(9)
• smp_call_function_any(9)
• smp_call_function_many(9)
• on_each_cpu_cond_mask(9)
• kick_all_cpus_sync(9)
• wake_up_all_idle_cpus(9)
• cpus_peek_for_pending_ipi(9)
• struct smp_call_on_cpu_struct(9)
• smp_call_on_cpu(9)

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okay that's the whole page, mwah 💋 this one's from ./kernel, dated October 2026, and it's filed under smp_call_function(9) — slay, go forth and call your functions on all the other CPUs responsibly 🧚💜