LIBPFM(3)

💖 LIBPFM(3) — the libpfm girlies' manual page 💖

okay so bestie, welcome to the libpfm glow-up era ✨ this is section 3 of the Linux Programmer's Manual, and we're about to get so cozy with it.

🌸 NAME 🌸

libpfm_amd64_fam1ah_zen6 — support for AMD64 Family 1Ah processors

like, that's the whole vibe. it's the libpfm module that holds it down for AMD64 Family 1Ah. periodt. 👑

✨ SYNOPSIS ✨

#include <perfmon/pfmlib.h>

• PMU name: amd64_fam1ah_zen6
• PMU desc: AMD64 Fam1Ah Zen6

that include line? literally the key to the whole kingdom, don't lose it 🗝️

💅 DESCRIPTION 💅

The library supports AMD Family 1Ah processors Zen6 core PMU in both 32 and 64-bit modes. yes bestie, both — 32-bit and 64-bit, she's flexible, she contains multitudes 🦋 no cap.

🎀 MODIFIERS 🎀

okay so these are the modifiers supported on the AMD64 Family 1Ah Zen6 core PMU. they're the little seasoning you sprinkle on an event to change what it does. put some respect on their names:

• u — Measure at user level, which includes privilege levels 1, 2, 3. This corresponds to PFM_PLM3. It's a boolean modifier — so it's just vibes, on or off ✅
• k — Measure at kernel level, which includes privilege level 0. This corresponds to PFM_PLM0. Also a boolean modifier 👑
• h — Measure while executing in host mode (that's when you're using virtualization). This corresponds to PFM_PLMH. Heads up: this modifier is available starting with Fam10h 🔥 boolean modifier energy.
• g — Measure while executing in guest mode (again, that's the virtualization life). This modifier is available starting with Fam10h 🌈 boolean modifier, obviously.
• i — Invert the meaning of the event. The counter will now count cycles in which the event is not occurring. like, the event but make it the opposite 💀 boolean modifier.
• e — Enable edge detection, i.e., count only when there is a state transition. dramatic! only the moments matter, not the sustained vibe — main character energy fr fr. boolean modifier.
• c — Set the counter mask value. The mask acts as a threshold: the counter will count the number of cycles in which the number of occurrences of the event is greater or equal to the threshold. 📈 this one is an integer modifier with values in the range [0:255] — so like, pick a number, bestie. number goes in, threshold goes on.

no cap: i, e and c change what actually gets counted, so know what you're doing before you send it 🫶

🌟 AUTHORS 🌟

• Swarup Sahoo
• Nitika Achra

absolute icons, we stan 🙌

that's the whole page, bestie — you ate that read 💅 this one's from the Linux Programmer's Manual, section 3, dated May, 2026, running under the LIBPFM banner, and honestly? iconic 🎀 bye love u, go count some events ✨💖