scx_bpf_tes...ear_cpu_idle(9)

📦 version 7.3.1, in nixpkgs unstable

💅 scx_bpf_test_and_clear_cpu_idle — NAME

okay so bestie, welcome to the Kernel API Manual ✨ — this one's called scx_bpf_test_and_clear_cpu_idle, and it does exactly what it says on the tin: test and clear @cpu's idle state 🎀

🌸 SYNOPSIS

__bpf_kfunc bool scx_bpf_test_and_clear_cpu_idle (s32 cpu , const struct bpf_prog_aux *aux );

that's the whole signature, no cap 👑

🦋 ARGUMENTS

  • cpu — the cpu we're test-and-clearing the idle state for 🧚 like, this one right here
  • aux — the implicit BPF argument to access bpf_prog_aux, and it's hidden from BPF progs 🙈 so don't come looking for it, it's not for you

✨ DESCRIPTION

returns true if cpu was idle and its idle state was successfully cleared ✅ false otherwise 💀 that's it, that's the vibe check.

🚨 important caveat, bestie, do not skip this: it's unavailable if ops.update_idle is implemented and SCX_OPS_KEEP_BUILTIN_IDLE is not set. like, literally not available. so if you're rolling your own idle handling, this function is not your main character 😭

👑 SEE ALSO

kernel file: ./kernel/sched/ext/idle.c — that's where the sauce lives 🍓

and the whole friend group 🔥:

mwah 💜 that's the page! brought to you by ./kernel/sched/ext, dated October 2026 — go clear some idle states, bestie, ily 🫶

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