NAME

       pmdapapi - papi performance metrics domain agent (PMDA)

SYNOPSIS

       $PCP_PMDAS_DIR/pmdapapi [-d domain] [-l logfile]

DESCRIPTION

       pmdapapi  is  a  papi Performance Metrics Domain Agent (PMDA) which exposes hardware performance counters
       via the library Performance API (PAPI).

       The metrics exported by the papi PMDA report values gathered  from  the  hardware  counters  and  metrics
       available, as reported by papi.  Currently, only root users may access such metrics.

       A brief description of the pmdapapi 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 papi.log is written in the current directory
            of pmcd(1) when pmdapapi 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.

       Performance  counters are activated automatically as they are fetched cyclically (such as via pmval(1) or
       pmlogger(1)).  This automatic activation is temporary, and lasts only a number of seconds governed by the
       papi.control.auto_enable  control  value (default 120).  In the case automatic activation is undesirable,
       one may disable it by setting the papi.control.auto_enable metric to 0.

       Alternately, the pmstore(1) command can be used to permanently enable  tracking  particular  metrics,  or
       stop  them  on  demand.   Using the papi.control.enable and papi.control.disable metrics, one may set the
       metrics you wish to track using a space or comma  separated  list.   Writing  to  the  papi.control.reset
       metric  disables  all  counters  immediately.   This may be useful if the system performance counters are
       needed for another profiling task.

            # pmstore papi.control.enable "TOT_CYC TOT_INS"
            papi.control.enable old value="" new value="TOT_CYC TOT_INS"

            # pmval papi.system.TOT_CYC
                        8.371E+04
            # pmval papi.system.TOT_INS
                        2.712E+04
            # pmstore papi.control.disable "TOT_CYC,TOT_INS"
            papi.control.disable old value="" new value="TOT_CYC,TOT_INS"

       Fetching the papi.control.status metric provides an overview of all active counters.

       By default, PAPI multiplexing, which allows support for collecting more metrics  than  supported  by  the
       hardware  concurrently,  is  enabled.   One  may  modify  the  papi.control.multiplex  metric  to disable
       multiplexing by setting it to 0.

       Where possible, pmdapapi will expose available native perf and uncore events on the current hardware.  It
       is not possible to count some native metrics and preset metrics concurrently.

            # true -- automatically-enabled counters
            # pmval -s3 papi.system.perf.BRANCH.LOADS
            metric:    papi.system.perf.BRANCH.LOADS
            host:      HOSTNAME
            semantics: cumulative counter (converting to rate)
            units:     count (converting to count / sec)
            samples:   3
            interval:  1.00 sec
                        7530.
                        7539.
                        7543.

            # pmval -s3 papi.system.perf.BRANCH.MISSES
            metric:    papi.system.perf.BRANCH.MISSES
            host:      HOSTNAME
            semantics: cumulative counter (converting to rate)
            units:     count (converting to count / sec)
            samples:   3
            interval:  1.00 sec
                         696.8
                         590.8
                         651.8

            # true -- quick overview
            # pminfo -f papi.control.status
            papi.control.status
                value "Papi is running, has multiplexing enabled, perf.BRANCH.MISSES(114): 8960, perf.BRANCH.LOADS(110): 158400"

            # true -- optional instant disable
            # pmstore papi.control.disable "perf.BRANCH.LOADS,perf.BRANCH.MISSES"
            papi.control.disable old value="" new value="perf.BRANCH.LOADS,perf.BRANCH.MISSES"

INSTALLATION

       If  you want access to the names, help text and values for the papi performance metrics, do the following
       as root:

            # cd $PCP_PMDAS_DIR/papi
            # ./Install

       If you want to undo the installation (and remove both PMDAs), do the following as root:

            # cd $PCP_PMDAS_DIR/papi
            # ./Remove

       pmdapapi 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 pmdapapi
       $PCP_PMDAS_DIR/papi/help
                 default help text file for the papi metrics
       $PCP_PMDAS_DIR/papi/Install
                 installation script for the pmdapapi agent
       $PCP_PMDAS_DIR/papi/Remove
                 undo installation script for the pmdapapi agent
       $PCP_LOG_DIR/pmcd/sample.log
                 default log file for error messages and other information from pmdapapi

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).

SEE ALSO

       PCPIntro(1), pmcd(1), pcp.conf(5) and pcp.env(5).