SystemTap PMDA
==============

This PMDA uses the SystemTap Linux kernel trace infrastructure to obtain
performance data.  Both SystemTap and this PMDA are easily configurable,
allowing arbitrary trace points to be monitored.  The PMDA itself is all
Perl code, and thus easily extended to monitor additional types of trace
information from SystemTap.

The file $PCP_PMDAS_DIR/probes.stp contains the SystemTap script which
will be run by the stap(1) command to insert the kernel instrumentation.
It is intended that once suitable instrumentation has been found running
SystemTap interactively, that a modified probes.stp and PMDA would then
be installed to export the interesting data to PCP clients (for logging,
charting, etc).

Metrics
=======

The file ./help contains descriptions for all of the metrics exported
by this PMDA.

Once the PMDA has been installed, the following command will list all
the available metrics and their explanatory "help" text:

	$ pminfo -fT systemtap

Installation
============

 +  # cd $PCP_PMDAS_DIR/systemtap

 +  Check that there is no clash in the Performance Metrics Domain
    defined in ./domain.h and the other PMDAs currently in use (see
    $PCP_PMCDCONF_PATH).  If there is, edit pmdasystemtap.pl to use
    a different domain number.

 +  Then simply use

	# ./Install

    and choose both the "collector" and "monitor" installation
    configuration options.

De-installation
===============

 +  Simply use

	# cd $PCP_PMDAS_DIR/systemtap
	# ./Remove

Troubleshooting
===============

 +  After installing or restarting the agent, the PMCD log file
    ($PCP_LOG_DIR/pmcd/pmcd.log) and the PMDA log file
    ($PCP_LOG_DIR/pmcd/systemtap.log) should be checked for any
    warnings or errors.
