LIBPFM(3)

💖 LIBPFM 💖

(that's the libpfm page from the Linux Programmer's Manual, bestie — section 3, the library girlies ✨)

🌸 NAME 🌸

libpfm_intel_spr_unc_upi — support for the Intel SapphireRapids Server UPI uncore PMU 🦋

✨ SYNOPSIS ✨

#include <perfmon/pfmlib.h>

• PMU name: spr_unc_upi[0-3]
• PMU desc: Intel SapphireRapids UPI uncore PMU

👑 DESCRIPTION 👑

okay so. This library supports the Intel SapphireRapids UPI — that's Ultra Path Interconnect, iykyk — uncore PMU. 💅

And literally, each UPI PMU implements 4 generic counters. four. that's the whole count. iconic behavior honestly. 🔥

🎀 MODIFIERS 🎀

here's the modifiers that are supported on the Intel SapphireRapids UPI uncore PMU, bestie, don't skip these:

• e — turns on edge detection, meaning it counts only when there's a state transition, going from zero occurrences of the event to at least one occurrence. 💫 But heads up: this modifier must be combined with a threshold modifier (t) with a value greater or equal to one. It's a boolean modifier.
• t — sets the threshold value. When you set it to a non-zero value, the counter counts the number of IRP clockticks in which the number of occurrences of the event is greater or equal to the threshold. This is an integer modifier, and the values live in the range [0:255]. 🌈
• i — inverts the threshold (t) test, flipping it from strictly greater than to less or equal to. This is a boolean modifier. 🙈

💜 AUTHORS 💜

Stephane Eranian <eranian@gmail.com> — periodt. 🫶

and that's the whole page, bestie!! 💖 this one came out of the Linux Programmer's Manual, it's LIBPFM(3), and it's stamped January, 2024 — so if you're reading it way later, that's the vintage. 🌸 mwah, go count some clockticks 🦋✨