is_pmu_core(9)

✨ NAME ✨

is_pmu_core — okay so this one is literally just a vibe check for PMU names: it checks whether the name you hand it belongs to a core CPU PMU 💅 (and yes, this is the Kernel API Manual, hi bestie, welcome 🫶)

🌸 SYNOPSIS 🌸

bool is_pmu_core (const char *name );

🎀 ARGUMENTS 🎀

• name — the PMU name you want checked, bestie. That's it. That's the whole argument. She's low maintenance 💖

🦋 DESCRIPTION 🦋

So how do we know a PMU is a core PMU? There are exactly two ways, and ngl they're both kind of iconic in their own little way 👑

1. Exact name match — like, the name is the name, no games:
   • "cpu" — typically used on x86 architectures 💻
   • "cpum_cf" — typically used on s390 architectures (that's the CPU Measurement Counter Facility, iykyk) 🧚
   • "default_core" — a generic name used to refer to the default core PMU ✨
2. Sysfs file existence check (is_sysfs_pmu_core) — the "does the file even exist" method:
   • Typically used on ARM systems or Intel hybrid architectures (e.g. "cpu_atom", "cpu_core"). This approach checks if the sysfs directory for the PMU contains a "cpus" file 🌈

fr fr, that's the entire detection strategy — name match or "is there a cpus file in there". Simple, effective, slay 💅

🔥 SEE ALSO 🔥

• Kernel file ./tools/perf/util/pmu.c
• struct perf_pmu_alias(9)
• is_sysfs_pmu_core(9)
• perf_pmu__match_wildcard(9)
• perf_pmu__match_ignoring_suffix_uncore(9)
• perf_pmu__match_wildcard_uncore(9)
• perf_pmu__name_wildcard_match(9)
• perf_pmu__name_no_suffix_match(9)

And that's the whole page, bestie 🎀 brought to you by ./tools/perf/util, stamped October 2026, filed under is_pmu_core(9). Go check those core PMU names, periodt 💜🌸