STRUCT PERF_CPU(9)

💅 struct perf_cpu(9) — from the Kernel API Manual, bestie

okay so real talk, this one is a tiny little legend and i need you to appreciate it. it's struct perf_cpu, and it's basically a glow-up wrapper around a CPU number. that's it. that's the whole vibe. ✨

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🎀 NAME

struct perf_cpu — a wrapper around a CPU number. lowkey iconic for how small it is.

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🌸 SYNOPSIS

struct perf_cpu {
    int16_t cpu;
 };

yes bestie, that's the entire struct. no cap. she's compact and she knows it. 💅

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🦋 Members

• cpu — the CPU number itself. and listen: it's -1 for the "any CPU" / dummy value. so if you see a -1 in there, that's not a glitch, that's her saying "any CPU, idc, whichever" 🫶

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💖 Description

okay so here's the tea — it's int16_t, which means this whole thing is capped at 32767 CPUs. that's the limit, periodt. 🔥

and widening it to int? not free, babe. that requires a libperf ABI bump, so it's a whole thing. if you want the full scope of that saga, go look at tools/lib/perf/TODO — it's all laid out in there. iykyk 😭

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👑 SEE ALSO

• Kernel file: ./tools/lib/perf/include/perf/cpumap.h
• perf_cpu_map__new_any_cpu(9)
• perf_cpu_map__new_online_cpus(9)
• perf_cpu_map__new(9)
• perf_cpu_map__cpu(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)

like, go read the whole cpumap family, they're all main character energy together fr fr 🌈

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and that's the page!! source/version live at ./tools/lib/perf/include/perf, dated October 2026 — so yes, she's recent, she's fresh, she ate and left no crumbs 🍓💜 go forth and map those CPUs bestie 🧚⭐