LIBPFM(3)

💖 LIBPFM(3) — Linux Programmer's Manual 💖

okay bestie, sit down, hydrate, and let me tell you about a very specific little corner of the perfmon2 library 💅

✨ NAME ✨

libpfm_intel_hswep_unc_imc — the support module for the Intel Haswell-EP Integrated Memory Controller (IMC) uncore PMU 🧠✨

🌸 SYNOPSIS 🌸

#include <perfmon/pfmlib.h>

• PMU name: hswep_unc_imc[0-7]
• PMU desc: Intel Haswell-EP IMC uncore PMU

🦋 DESCRIPTION 🦋

So the library does support the Intel Haswell Integrated Memory Controller (IMC) uncore PMU. Obsessed. 💖

But real talk — this PMU model only exists on Haswell model 63. Not 62, not 64, not "close enough". Model 63 or it's not happening, no cap. 🙈

🎀 MODIFIERS 🎀

These are the modifiers supported on the Intel Haswell C-Box uncore PMU. Yes, it says C-Box here, that's just what it says, don't come for me 🫶

• e — enable edge detection, i.e. count only when there's a state transition from no occurrence of the event to at least one occurrence. This modifier must be combined with a threshold modifier (t) with a value greater or equal to one. It's a boolean modifier, so it's giving on/off energy. ✨
• t — set the threshold value. When you set it to a non-zero value, the counter counts the number of IMC cycles 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 — invert the meaning of the threshold or edge filter. If it's set, the event counts when strictly less than N occurrences occur per cycle, if threshold is set to N. When invert is set, then threshold must be set to a non-zero value. And if it's set, the event counts when the event transitions from occurring to not occurring (falling edge) when edge detection is set. This is a boolean modifier. 💀

👑 AUTHORS 👑

Stephane Eranian <eranian@gmail.com>

fr fr, that's the whole page. every flag, every range, every "must" — all of it, untouched, just vibing. 💜

this was LIBPFM(3) from the Linux Programmer's Manual, brought to you in May, 2015 🌈 — bye bestie, go count some uncore events responsibly 🧚💖