LIBPFM(3)

💖 LIBPFM 💖

ok so bestie, you're reading the libpfm manual, page LIBPFM(3) from the Linux Programmer's Manual. buckle up, this one's about a very specific little PMU and it's giving niche-icon energy 🎀

✨ NAME ✨

libpfm_intel_bdx_unc_r2pcie — the whole vibe is: support for the Intel Broadwell Server R2 PCIe uncore PMU 🦋

🌸 SYNOPSIS 🌸

#include <perfmon/pfmlib.h>

• PMU name: bdx_unc_r2pcie
• PMU desc: Intel Broadwell Server R2 PCIe uncore PMU

👑 DESCRIPTION 👑

ok so here's the tea: this library supports the Intel Broadwell server R2 PCIe uncore PMU. no cap.

and listen — this PMU model only exists on Broadwell server models (79, 86). like, that's it. if you're not on one of those, this page is not for you, sorry bestie 😭

💅 MODIFIERS 💅

the following modifiers are supported on the Intel Broadwell server R2PCIe uncore PMU:

• 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 on or off, periodt.
• t — set the threshold value. when you set it to a non-zero value, the counter counts the number of R2PCIe 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 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. if 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 💅

ngl, e and i both being boolean is a whole mood, but they do completely different things — read carefully, bestie 🫶

🫶 AUTHORS 🫶

• Stephane Eranian <eranian@gmail.com> — an absolute icon for writing this 👑

and that's the page, fr fr 💖 this one's from the Linux Programmer's Manual, dated June, 2017, and it lives at page LIBPFM(3). slay, go count some PCIe events, ily bye 🎀🌈⭐