on_each_cpu_mask(9)

Okay bestie, buckle up 🎀 — this is the on_each_cpu_mask(9) page from the Kernel API Manual, and it's literally about running a function on processors specified by cpumask, which may include the local processor. 👀💅

🌸 NAME 🌸

• on_each_cpu_mask — run a function on processors specified by cpumask, which may include the local processor. ✨

✨ SYNOPSIS ✨

void on_each_cpu_mask (const struct cpumask *mask , smp_call_func_t func , void *info , bool wait );

💅 ARGUMENTS 💅

• mask — the set of cpus to run on (only runs on the online subset). 🫶
• func — the function to run. This must be fast and non-blocking, no cap. ⚡
• info — an arbitrary pointer to pass to the function. literally whatever pointer you need to hand over. 🎀
• wait — if true, wait (atomically) until the function has completed on other CPUs. 💫

🦋 DESCRIPTION 🦋

Okay so here's the tea: if wait is true, then it returns once func has returned. Periodt. 💅

🚨 Warning bestie: you must not call this function with disabled interrupts, or from a hardware interrupt handler, or from a bottom half handler. That's a hard no — those vibes do not mix. 😭

The one exception is iconic: it may be used during early boot while early_boot_irqs_disabled is set. 👑✨

🔥 SEE ALSO 🔥

• Kernel file ./include/linux/smp.h 📁
• smp_processor_id(9) 👀

xoxo, your kernel bestie 💋 — this page lives in ./include/linux, is dated October 2026, and goes by on_each_cpu_mask(9). 🫶✨