em_pd_nr_perf_states(9)

💖 em_pd_nr_perf_states (9) — Kernel API Manual ✨

okay so bestie, welcome to section 9 of the kernel API manual, and today we're looking at em_pd_nr_perf_states — yes that's a whole mouthful, i know, but it's literally so much simpler than it sounds 🫶

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🌸 NAME 🌸

em_pd_nr_perf_states — get the number of performance states of a perf. domain 💅

like, that's it. that's the whole job. it counts the performance states for you so you don't have to. iconic behaviour honestly.

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✨ SYNOPSIS ✨

int em_pd_nr_perf_states (struct em_perf_domain *pd );

copy it exactly like that, spaces and all, no cap — the kernel does not play about formatting 🙈

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🎀 ARGUMENTS 🎀

• pd — the performance domain you want this done for 🦋 that's the one you're asking about, the main character of this little function call tbh

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⭐ RETURN ⭐

it hands you back the number of performance states in the performance domain table 🔥 that's the count, that's the tea, that's the answer. no dramatic twist, she just tells you how many there are 💜

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🌈 SEE ALSO 🌈

• Kernel file ./include/linux/energy_model.h — literally the whole vibe lives in here, go read it 💖
• struct em_perf_state(9)
• struct em_perf_table(9)
• struct em_perf_domain(9)
• em_pd_get_efficient_state(9)
• em_cpu_energy(9)
• em_perf_state_from_pd(9)

all of these are your girls too, go say hi 👑 (iykyk)

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ngl this one's a short read because the function is short — the way that a good manpage doesn't need to overexplain itself 💅 lowkey refreshing.

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and that's the page bestie!! 🍓 it lives over in ./include/linux, dated October 2026 — so go forth, count those performance states, and slay ✨🧚‍♀️🌷