evsel__read_on_cpu(9)

📦 version 7.3.1, in nixpkgs unstable

✨ evsel__read_on_cpu(9) ✨

okay so bestie, this one is from the Kernel API Manual, and it's literally about reading out the results on a CPU and thread. lowkey short page, highkey useful. let's get into it 🫶

💖 NAME 💖

evsel__read_on_cpu — read out the results on a CPU and thread, periodt 💅

🦋 SYNOPSIS 🦋

int evsel__read_on_cpu (struct evsel *evsel , int cpu_map_idx , int thread );

that's the whole signature, no cap. it returns an int, and the args are exactly evsel, cpu_map_idx, and thread. copy it character-for-character if you're typing it out, bestie 🎀

🎀 ARGUMENTS 🎀

  • evsel — the original says -- undescribed -- and honestly the doc is leaving us on read here 🙈
  • cpu_map_idx — also -- undescribed --, not me having to report that 😭
  • thread — same energy: -- undescribed -- 💀
yes bestie, all three are literally listed as undescribed in this section. the DESCRIPTION is where the plot thickens ✨

🔥 DESCRIPTION 🔥

okay so the description comes through and gives us the deets:

  • evsel — event selector to read value 👑
  • cpu_map_idx — CPU of interest 🖥️
  • thread — thread of interest 🧵

that's the vibe: you got your event selector, you got the CPU you care about, and you got the thread you care about. iconic, concise, no notes 🌸

🌈 SEE ALSO 🌈

the kernel file ./tools/perf/util/evsel.h is main character energy here, and you should also peek at:

iykyk, go read those next 💖

final cute sign-off: this lil page lives under ./tools/perf/util, dated October 2026, and it's the evsel__read_on_cpu(9) manual page. bye bestie, slay responsibly 🫶💅✨

📦 where this page comes from