cpumask_test_cpu(9)

📦 version 7.3.1, in nixpkgs unstable

💅 cpumask_test_cpu — the Kernel API Manual moment we've all been waiting for

okay so bestie, listen. This is a page from the Kernel API Manual (yes, that one, the cpumask_test_cpu(9) page, main character energy fr) and it's honestly such a vibe check for one specific CPU. Let's get into it 🎀

✨ NAME ✨

cpumask_test_cpu — literally just testing whether a cpu is in a cpumask. That's it. That's the whole job. And she does it flawlessly 👑

🌸 SYNOPSIS 🌸

bool cpumask_test_cpu (int cpu , const struct cpumask *cpumask );

🦋 ARGUMENTS 🦋

  • cpu — the cpu number, and ngl there's a rule: it has to be < nr_cpu_ids. So like, valid cpu numbers only, no clownery 🙈
  • cpumask — the cpumask pointer. Your mask. Your little roster. She needs the pointer, not the whole struct, we're being efficient here 💅

💖 RETURN 💖

Returns true if cpu is set in cpumask, else returns false.

That's it. Binary. Iconic. No "maybe", no "it depends" — just true or false, periodt ⭐

🫶 SEE ALSO 🫶

Kernel file: ./include/linux/cpumask.h

okay this list is LONG but every single one of these is a sibling and they all deserve their moment, so here's the whole family:

ngl if you're only here for one bit of info: true = the cpu is in the mask, false = she's not. that's the tea ☕

anyway bestie, this page came straight out of ./include/linux, dated October 2026, and it's filed under cpumask_test_cpu(9) — go forth and test those cpus 💜✨🌸

📦 where this page comes from