perf_cpu_map__cpu(9)

💅 perf_cpu_map__cpu(9) 💅

okay bestie, welcome to the Kernel API Manual — yes, that's the manual name, i don't make the rules 🎀 — and today's main character is perf_cpu_map__cpu. periodt.

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✨ NAME ✨

perf_cpu_map__cpu — grab the CPU value sitting at whatever index you hand it. and if that index is invalid? it hits you with a -1. no cap, that's the whole vibe check. 💀

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🌸 SYNOPSIS 🌸

LIBPERF_API struct perf_cpu perf_cpu_map__cpu (const struct perf_cpu_map *cpus , unsigned int idx );

that's the whole signature, copied character for character because we do not play with code around here 🫶

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🦋 ARGUMENTS 🦋

okay so this is where it gets a little iconic in the "the docs said nothing" way 😭

• cpus — -- undescribed -- … yeah. that's literally it. the manpage gives us nothing on this one. we simply do not know. 🙈
• idx — -- undescribed -- … same situation, bestie. the tea is lukewarm. 🍓

not me reading the arguments section twice expecting more 💀 the original genuinely lists both as -- undescribed --, so that's exactly what you're getting. no invented lore here, i'm not about to make stuff up and lie to you ✨

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🔥 SEE ALSO 🔥

go touch some other manpages, they're all linked together like one big friend group 🌈

• Kernel file ./tools/lib/perf/include/perf/cpumap.h struct perf_cpu(9)
• perf_cpu_map__new_any_cpu(9)
• perf_cpu_map__new_online_cpus(9)
• perf_cpu_map__new(9)
• perf_cpu_map__nr(9)
• perf_cpu_map__has_any_cpu_or_is_empty(9)
• perf_cpu_map__is_any_cpu_or_is_empty(9)
• perf_cpu_map__is_empty(9)
• perf_cpu_map__min(9)
• perf_cpu_map__max(9)

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🧚 cute lil sign-off 🧚

this page lives in ./tools/lib/perf/include/perf, dated October 2026 — mark your calendars, bestie 👑 and that's the whole page, you ate that 💖

mwah 💋 go call perf_cpu_map__cpu responsibly