'\"macro stdmacro
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.ds ia papi
.ds IA PAPI
.ds Ia Papi
.TH PMDAPAPI 1 "PCP" "Performance Co-Pilot"
.SH NAME
\f3pmdapapi\f1 \- \*(ia performance metrics domain agent (PMDA)
.SH SYNOPSIS
\f3$PCP_PMDAS_DIR/pmda\*(ia\f1
[\f3\-d\f1 \f2domain\f1]
[\f3\-l\f1 \f2logfile\f1]
.SH DESCRIPTION
.B pmda\*(ia
is a \*(ia Performance Metrics Domain Agent (PMDA) which exposes
hardware performance counters via the library Performance API (PAPI).
.PP
The metrics exported by the \*(ia PMDA report values gathered from
the hardware counters and metrics available, as reported by \*(ia.
Currently, only root users may access such metrics.
.PP
A brief description of the
.B pmda\*(ia
command line options follows:
.TP 5
.B \-d
It is absolutely crucial that the performance metrics
.I domain
number specified here is unique and consistent.
That is,
.I domain
should be different for every PMDA on the one host, and the same
.I domain
number should be used for the same PMDA on all hosts.
.TP
.B \-l
Location of the log file.  By default, a log file named
.I \*(ia.log
is written in the current directory of
.BR pmcd (1)
when
.B pmda\*(ia
is started, i.e.
.BR $PCP_LOG_DIR/pmcd .
If the log file cannot
be created or is not writable, output is written to the standard error instead.
.P
Performance counters are activated automatically as they are fetched
cyclically (such as via
.BR pmval (1)
or
.BR pmlogger (1)).
This automatic activation is temporary, and lasts only a number of seconds
governed by the
.B papi.control.auto_enable
control value (default 120).  In the case automatic activation is undesirable, one may
disable it by setting the
.B papi.control.auto_enable
metric to 0.
.P
Alternately, the
.BR pmstore (1)
command can be used to permanently enable tracking particular metrics, or stop them
on demand.  Using the
.B papi.control.enable
and
.B papi.control.disable
metrics, one may set the metrics you wish to track using a space or comma separated list.
Writing to the
.B papi.control.reset
metric disables all counters immediately.  This may be useful if the system performance
counters are needed for another profiling task.
.P
.ft CW
.nf
.in +0.5i
# 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"
.in
.fi
.P
Fetching the
.BR papi.control.status
metric provides an overview of all active counters.
.P
By default, PAPI multiplexing, which allows support for collecting more metrics
than supported by the hardware concurrently, is enabled.  One may modify the
.B papi.control.multiplex
metric to disable multiplexing by setting it to 0.
.P
Where possible,
.B pmda\*(ia
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.
.P
.ft CW
.nf
.in +0.5i
# 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"
.PP
.SH INSTALLATION
If you want access to the names, help text and values for the \*(ia
performance metrics, do the following as root:
.PP
.ft CW
.nf
.in +0.5i
# cd $PCP_PMDAS_DIR/\*(ia
# ./Install
.in
.fi
.ft 1
.PP
If you want to undo the installation (and remove both PMDAs),
do the following as root:
.PP
.ft CW
.nf
.in +0.5i
# cd $PCP_PMDAS_DIR/\*(ia
# ./Remove
.in
.fi
.ft 1
.PP
.B pmda\*(ia
is launched by
.BR pmcd (1)
and should never be executed directly.
The Install and Remove scripts notify
.BR pmcd (1)
when the agent is installed or removed.
.SH FILES
.PD 0
.TP 10
.B $PCP_PMCDCONF_PATH
command line options used to launch
.B pmda\*(ia
.TP 10
.B $PCP_PMDAS_DIR/\*(ia/help
default help text file for the \*(ia metrics
.TP 10
.B $PCP_PMDAS_DIR/\*(ia/Install
installation script for the
.B pmda\*(ia
agent
.TP 10
.B $PCP_PMDAS_DIR/\*(ia/Remove
undo installation script for the 
.B pmda\*(ia
agent
.TP 10
.B $PCP_LOG_DIR/pmcd/sample.log
default log file for error messages and other information from
.B pmda\*(ia
.PD
.SH "PCP ENVIRONMENT"
Environment variables with the prefix
.B PCP_
are used to parameterize the file and directory names
used by PCP.
On each installation, the file
.B /etc/pcp.conf
contains the local values for these variables.
The
.B $PCP_CONF
variable may be used to specify an alternative
configuration file,
as described in
.BR pcp.conf (5).
.SH SEE ALSO
.BR PCPIntro (1),
.BR pmcd (1),
.BR pcp.conf (5)
and
.BR pcp.env (5).