PMC_START(3)

✨ NAME ✨

Okay so this is PMC_START(3), straight outta the Library Functions Manual, and the main characters are pmc_start, pmc_stop — they start and stop a PMC. Periodt. 🎀

🌸 LIBRARY 🌸

Performance Counters Library (libpmc, -lpmc) — that's where these babies live.

🦋 SYNOPSIS 🦋

#include <pmc.h>

int
pmc_start(pmc_id_t pmc);

int
pmc_stop(pmc_id_t pmc);

💜 DESCRIPTION 💜

Okay so these functions are literally the on/off switch for a PMC.

pmc_start() starts the PMC specified by argument pmc. And here's the cute little detail: if the specified PMC has process scope and has not been attached to any targets, it will be attached to the current process. It's giving "you're mine now" energy. 🫶

pmc_stop() stops the PMC specified by argument pmc. That's it. That's the tea. ☕

🔥 RETURN VALUES 🔥

If it works, you get 0 back. If it doesn't, you get -1, and the global variable errno is set to indicate the error. So check errno, bestie — it's literally telling you what happened. 😭

💅 ERRORS 💅

A call to these functions may fail with the following errors:

• EDOOFUS — pmc_start() specified a PMC that requires a log file and no log file was configured. Iconic error name, ngl.
• EINVAL — the specified PMC is in the process of being deleted. Mid-deletion, not cute.
• EINVAL — pmc_stop() specified a PMC that was never started. You can't stop what never started, bestie.
• ENXIO — the specified PMC had system scope and its associated CPU was disabled or absent. Ghosted by the CPU. 💀

🌈 SEE ALSO 🌈

• pmc(3)
• hwpmc(4)

Go read those next, iykyk. 👑

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This page is from Debian and is dated September 22, 2008. Bye bestie, go start and stop those PMCs with main character energy 💖✨