STRUCT SAMPLE(9)

🌸 struct sample(9) — Kernel API Manual 🌸

okay so bestie, we're diving into struct sample from the kernel API manual and honestly?? it's giving "tiny struct, big responsibilities" 💅 lowkey it's the little data-holder that helps your CPU pick its next vibe (that's a P State, iykyk).

---

✨ NAME ✨

struct sample — Store performance sample 🎀

---

✨ SYNOPSIS ✨

struct sample {
    int32_t core_avg_perf;
    int32_t busy_scaled;
    u64 aperf;
    u64 mperf;
    u64 tsc;
    u64 time;
 };

---

✨ Members ✨

• core_avg_perf — the ratio of APERF/MPERF, which is literally the actual average performance during the last sample period. no cap, that's the whole thing 🫶
• busy_scaled — a scaled busy value, and it's the one used to calculate the next P state. it can be different from core_avg_perf so it can account for the cpu idle period — like yeah, she adjusts 💅
• aperf — the difference of the actual performance frequency clock count read from the APERF MSR between the last and current sample.
• mperf — the difference of the maximum performance frequency clock count read from the MPERF MSR between the last and current sample.
• tsc — the difference of the time stamp counter between the last and current sample ⭐
• time — current time from scheduler 🕐

---

✨ Description ✨

so this structure lives inside the cpudata structure and its whole job is storing performance sample data for choosing the next P State. that's it, that's the arc 🌈 main character energy but make it data storage, fr fr.

---

✨ SEE ALSO ✨

Kernel file ./drivers/cpufreq/intel_pstate.c with struct pstate_data(9), struct vid_data(9), struct global_params(9), struct cpudata(9), struct pstate_funcs(9). go read the whole friend group, they're all connected 🦋

---

ngl this one's short and sweet — but every field matters, so don't go skipping any of them 💖

---

and that's a wrap, bestie!! this page came from ./drivers/cpufreq and it's dated October 2026 — iconic of it, honestly. mwah 💋👑