---
name: "QMC"
section: "3"
platform: "linux"
package: "pcp"
version: "7.2.2-2"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://carta.tech/man/QMC"
---

# QMC(3)

library for managing groups of Performance Co-Pilot metrics

## NAME

**QMC** - library for managing groups of Performance Co-Pilot metrics

## C++ SYNOPSIS

**#include \<qmc.h\>**

**c++ ... -lpcp\_qmc -lpcp**

## DESCRIPTION

The Qt-based Performance Metrics Class (**QMC**) class library is a collection of C++ classes for managing a large set of performance metrics from a variety of sources.  This library is built over [**PMAPI**(3)](/man/PMAPI/3.md).

## DIAGNOSTICS

Error messages are generated using [**pmprintf**(3)](/man/pmprintf/3.md) but are not flushed. It is the responsibility of the user to call [**pmflush**(3)](/man/pmflush/3.md) to output any messages.

Additional diagnostics may be activated by adding the option **pmc** to the global debugging specification, as described in [**pmSetDebug**(3)](/man/pmSetDebug/3.md).

## SEE ALSO

[**PMAPI**(3)](/man/PMAPI/3.md), [**QmcContext**(3)](/man/QmcContext/3.md), [**QmcDesc**(3)](/man/QmcDesc/3.md), [**QmcGroup**(3)](/man/QmcGroup/3.md), [**QmcIndom**(3)](/man/QmcIndom/3.md), [**QmcMetric**(3)](/man/QmcMetric/3.md), [**QmcSource**(3)](/man/QmcSource/3.md), [**pmflush**(3)](/man/pmflush/3.md) and [**pmprintf**(3)](/man/pmprintf/3.md).