LIBPFM(3)

💖 LIBPFM(3) — the Linux Programmer's Manual, but make it cute 💖

okay bestie, sit down, we're reading the libpfm page for the Arm Neoverse V2 core PMU and honestly? it's giving iconic hardware energy. this is LIBPFM(3), part of the Linux Programmer's Manual, and yes we're doing the whole thing. no skimming. ✨

🌸 NAME 🌸

libpfm_arm_neoverse_v2 — it's the whole support package for the Arm Neoverse V2 core PMU. that's it. that's the job. she does one thing and she does it slay. 💅

🦋 SYNOPSIS 🦋

#include <perfmon/pfmlib.h>

and the lil identity card of this PMU:

• PMU name: arm_v2
• PMU desc: Arm Neoverse V2

like. arm_v2 is the name you actually type, and Arm Neoverse V2 is the human-readable glow-up version. iykyk. 🎀

👑 DESCRIPTION 👑

so the library straight up supports the Arm Neoverse V2 core PMU. that's the vibe.

this PMU supports 6 counters and privilege levels filtering — meaning you can decide which privilege level you're measuring at, which is lowkey the whole point of the modifiers section coming up next. and it can operate in both 32 and 64 bit modes, so whatever mode you're in, she's ready. no cap. 🌈

💅 MODIFIERS 💅

here's where it gets fun. these are the modifiers supported on Arm Neoverse V2, and every single one of them is a boolean modifier — on or off, yes or no, slay or not slay. 💖

• u — measure at the user level. this one corresponds to PFM_PLM3. boolean modifier, as established. ✅
• k — measure at the kernel level. this corresponds to PFM_PLM0. also a boolean modifier. 💙
• hv — measure at the hypervisor level. this corresponds to PFM_PLMH. boolean modifier, you guessed it. 🧚

three modifiers, three privilege levels, zero drama. periodt. 🫶

🌟 AUTHORS 🌟

the masterminds behind this, aka the main characters:

• John Linford <jlinford@nvidia.com>
• Stephane Eranian <eranian@gmail.com>

and that's the whole page, bestie!! written August, 2022, and it's page LIBPFM(3) from the Linux Programmer's Manual — so when you're citing it, that's the source and the date. now go measure something iconic. 💜🌸🦋✨