LIBPFM(3)

💖 LIBPFM(3) 💖

okay bestie, welcome to the Linux Programmer's Manual, section 3 — this one's all about libpfm, and honestly? it's giving niche-but-iconic. 🎀

✨ NAME ✨

libpfm_intel_hswep_unc_ubo — support for the Intel Haswell-EP U-Box uncore PMU. that's the whole vibe. no cap. 💅

🦋 SYNOPSIS 🦋

#include <perfmon/pfmlib.h>

• PMU name: hswep_unc_ubo
• PMU desc: Intel Haswell-EP U-Box uncore PMU

🌸 DESCRIPTION 🌸

so like, this library? it supports the Intel Haswell system configuration unit (U-Box) uncore PMU. 🫶

and listen — this PMU model only exists on Haswell model 63. like, that's the one and only place it lives. if you're not on model 63, this is not your moment, bestie. 💀

👑 MODIFIERS 👑

the following modifiers are supported on the Intel Haswell U-Box uncore PMU — gather round, there's only three but they're important:

• 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. ✨ heads up though: this modifier must be combined with a threshold modifier (t) with a value greater or equal to one. this is a boolean modifier. 🔥
• t — set the threshold value. when you set it to a non-zero value, the counter counts the number of HA cycles in which the number of occurrences of the event is greater or equal to the threshold. this is an integer modifier, with values in the range [0:15]. ⭐
• 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 edge detection is set? then with invert set, the event counts when the event transitions from occurring to not occurring (aka the falling edge, bestie 🍓). this is a boolean modifier. 💜

lowkey important: e needs t to be ≥ 1, and i needs t to be non-zero. don't fight the rules, they're just the rules. 🧚

💜 AUTHORS 💜

Stephane Eranian <eranian@gmail.com>

and that's the whole page, bestie! 🌈 source + version energy: this is LIBPFM(3), dated May, 2015, straight outta the Linux Programmer's Manual. slay, go count some uncore events. 💖✨🎀