__flush_smp...nction_queue(9)

💅 __flush_smp_call_function_queue — Kernel API Manual (9)

okay so bestie, welcome to the kernel API manual, section 9, and today's main character is __flush_smp_call_function_queue. yes it's a long name. yes it ate. let's get into it 🫶

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✨ NAME ✨

__flush_smp_call_function_queue — literally just flushes any pending smp-call-function callbacks. that's the whole job. she does one thing and she does it well 💅

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🎀 SYNOPSIS 🎀

void __flush_smp_call_function_queue (bool warn_cpu_offline );

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🌸 ARGUMENTS 🌸

• warn_cpu_offline — if you set this to 'true', she'll warn you when callbacks were queued on an offline CPU 👀 (yes, that's a whole situation). if you set it to 'false', she skips that check entirely. ur choice bestie, but choose wisely ✨

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🔥 DESCRIPTION 🔥

okay so the vibe: this function flushes any pending smp-call-function callbacks that are queued on this CPU. that's it. that's the mission 💖

who calls her? the generic IPI handler does, and also a CPU that's about to go offline — because we need all pending IPI callbacks to actually run before that CPU dips out completely. no leaving homework unfinished, no cap 🎓

the way she works: she loops through the call_single_queue and runs every single queued callback. all of them. no skips, no stragglers 🌈

⚠️ okay important!! she must be called with interrupts disabled. not "should", not "ideally" — must. consider that a vibe check you cannot fail 💀

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🦋 SEE ALSO 🦋

kernel file ./kernel/smp.c (that's her home base 🏠), plus all these iconic siblings and neighbors:

• csd_lock_is_stuck(9)
• generic_smp_call_function_single_interrupt(9)
• flush_smp_call_function_queue(9) — yes, the one without the leading underscores, she's different, iykyk
• smp_call_function_single(9)
• smp_call_function_single_async(9)
• smp_call_function_any(9)
• smp_call_function_many(9)
• smp_call_function(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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🍓 that's the whole page bestie, go flush some callbacks (interrupts disabled, remember!!) 😭💜

kisses, this was served fresh from ./kernel, dated October 2026 — kernel API manual, section 9, signing off 🧚✨👑