Ubuntu Manpage: pmdaperfevent - hardware performance counter performance metrics domain agent (PMDA)

NAME

       pmdaperfevent - hardware performance counter performance metrics domain agent (PMDA)

SYNOPSIS

       $PCP_PMDAS_DIR/perfevent/pmdaperfevent  [-d  domain]  [-l logfile] [-U username] [-i port]
       [-p] [-u socket] [-6]

DESCRIPTION

pmdaperfevent is a Performance Metrics Domain Agent (PMDA) that configures and reads the
hardware performance counters using the Linux kernel perf_event API.

The perfevent PMDA exports metrics for hardware performance counters that are configurable
from the Linux kernel perf_event API. The PMDA uses the libpfm4 library to access the
hardware performance counters so any counters that are supported in libpfm4 should be
available. Also included is the ability to read the Intel RAPL counters via direct MSR
access. The PMDA supports automatically loading different counters for each hardware
architecture. A single configuration file is used to specify the desired counters for each
hardware performance monitoring unit (PMU). The configuration file allows different
counters to be programmed on different CPUs and supports round-robin assignment of uncore
counters needed for some AMD chips.

The PMDA configures the counters to count events in both user and kernel mode. This means
that the hardware counters are unavailable to use by normal unprivileged user applications
when they are in use by the PMDA. The PMDA provides a mechanism to temporarily disable the
system-wide counters in order to allow normal users to be able to use the counters if they
wish. See perfalloc(1) for details.

A brief description of the pmdaperfevent command line options follows:

-d It is absolutely crucial that the performance metrics domain number specified here is
unique and consistent. That is, domain should be different for every PMDA on the one
host, and the same domain number should be used for the same PMDA on all hosts.

-l Location of the log file. By default, a log file named perfevent.log is written in
the current directory of pmcd(1) when pmdaperfevent is started, i.e.
$PCP_LOG_DIR/pmcd. If the log file cannot be created or is not writable, output is
written to the standard error instead.

-U User account under which to run the agent. The default is the privileged "root"
account.

-i listen on given port number for connection from pmcd(1)

-p communicate with pmcd(1) via stdin/stdout

-u expect pmcd(1) to connect on given unix domain socket

-6 expect pmcd(1) to connect on given ipv6 port (number or name)

INSTALLATION

       The  perfevent PMDA is not activated by default.  To install the PMDA, do the following as
       root:

            # cd $PCP_PMDAS_DIR/perfevent
            # ./Install

       If you want to undo the installation, do the following as root:

            # cd $PCP_PMDAS_DIR/perfevent
            # ./Remove

       pmdaperfevent is launched by pmcd(1) and should never be executed directly.   The  Install
       and Remove scripts notify pmcd(1) when the agent is installed or removed.

FILES

       $PCP_PMCDCONF_PATH
                 command line options used to launch pmdaperfevent
       $PCP_PMDAS_DIR/perfevent/perfevent.conf
                 default  configuration  file  for  the  PMDA. See perfevent.conf(5) for detailed
                 information.
       $PCP_PMDAS_DIR/perfevent/help
                 default help text file for the perfevent metrics
       $PCP_PMDAS_DIR/perfevent/Install
                 installation script for the pmdaperfevent agent
       $PCP_PMDAS_DIR/perfevent/Remove
                 undo installation script for the pmdaperfevent agent
       $PCP_LOG_DIR/pmcd/perfevent.log
                 default log file for error messages and other information from pmdaperfevent

UPGRADING

       Some metric names have changed starting in  version  3.10.8  to  better  conform  to  PMNS
       conventions.   pmlogrewrite(1)  can  be  used  to  update old archives.  A helper utility,
       $PCP_PMDAS_DIR/perfevent/perfevent-makerewrite.pl will generate  a  config  file  that  is
       suitable for use with pmlogrewrite(1) to update the metric names in existing archives.

BUGS

       Each event is placed in its own group and there is no way to group related events together
       so they are guaranteed to be simultaneously active.  A workaround for this  is  to  ensure
       that  the  number  of  configured  events is less than or equal to the number of available
       hardware counters. This means that the events will not be time-multiplexed by  the  kernel
       and will be simultaneously active.

PCP ENVIRONMENT

       Environment variables with the prefix PCP_ are used to parameterize the file and directory
       names used by PCP.  On each installation, the file /etc/pcp.conf contains the local values
       for  these  variables.   The  $PCP_CONF  variable  may  be  used to specify an alternative
       configuration file, as described in pcp.conf(5).