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PMCSTAT(8)		FreeBSD	System Manager's Manual		    PMCSTAT(8)

NAME
     pmcstat --	performance measurement	with performance monitoring hardware

SYNOPSIS
     pmcstat [-C] [-D pathname]	[-E] [-G pathname] [-M mapfilename] [-N]
	     [-O logfilename] [-P event-spec] [-R logfilename] [-S event-spec]
	     [-W] [-c cpu-spec]	[-d] [-g] [-k kerneldir] [-m pathname]
	     [-n rate] [-o outputfile] [-p event-spec] [-q] [-r	fsroot]
	     [-s event-spec] [-t process-spec] [-v] [-w	secs] [-z graphdepth]
	     [command [args]]

DESCRIPTION
     The pmcstat utility measures system performance using the facilities pro-
     vided by hwpmc(4).

     The pmcstat utility can measure both hardware events seen by the system
     as	a whole, and those seen	when a specified set of	processes are execut-
     ing on the	system's CPUs.	If a specific set of processes is being	tar-
     geted (for	example, if the	-t process-spec	option is specified, or	if a
     command line is specified using command), then measurement	occurs till
     command exits, or till all	target processes specified by the -t
     process-spec options exit,	or till	the pmcstat utility is interrupted by
     the user.	If a specific set of processes is not targeted for measure-
     ment, then	pmcstat	will perform system-wide measurements till interrupted
     by	the user.

     A given invocation	of pmcstat can mix allocations of system-mode and
     process-mode PMCs,	of both	counting and sampling flavors.	The values of
     all counting PMCs are printed in human readable form at regular intervals
     by	pmcstat.  The output of	sampling PMCs may be configured	to go to a log
     file for subsequent offline analysis, or, at the expense of greater over-
     head, may be configured to	be printed in text form	on the fly.

     Hardware events to	measure	are specified to pmcstat using event specifier
     strings event-spec.  The syntax of	these event specifiers is machine
     dependent and is documented in pmc(3).

     A process-mode PMC	may be configured to be	inheritable by the target
     process' current and future children.

OPTIONS
     The following options are available:

     -C	     Toggle between showing cumulative or incremental counts for sub-
	     sequent counting mode PMCs	specified on the command line.	The
	     default is	to show	incremental counts.

     -D	pathname
	     Create files with per-program samples in the directory named by
	     pathname.	The default is to create these files in	the current
	     directory.

     -E	     Toggle showing per-process	counts at the time a tracked process
	     exits for subsequent process-mode PMCs specified on the command
	     line.  This option	is useful for mapping the performance charac-
	     teristics of a complex pipeline of	processes when used in con-
	     junction with the -d option.  The default is to not to enable
	     per-process tracking.

     -G	pathname
	     Print callchain information to file pathname.  If argument
	     pathname is a ``-'' this information is sent to the output	file
	     specified by the -o option.

     -M	mapfilename
	     Write the mapping between executable objects encountered in the
	     event log and the abbreviated pathnames used for gprof(1) pro-
	     files to file mapfilename.	 If this option	is not specified, map-
	     ping information is not written.  Argument	mapfilename may	be a
	     ``-'' in which case this mapping information is sent to the out-
	     put file configured by the	-o option.

     -N	     Toggle capturing callchain	information for	subsequent sampling
	     PMCs.  The	default	is for sampling	PMCs to	capture	callchain
	     information.

     -O	logfilename
	     Send logging output to file logfilename.  If logfilename is of
	     the form hostname:port, where hostname does not start with	a `.'
	     or	a `/', then pmcstat will open a	network	socket to host
	     hostname on port port.

	     If	the -O option is not specified and one of the logging options
	     is	requested, then	pmcstat	will print a textual form of the
	     logged events to the configured output file.

     -P	event-spec
	     Allocate a	process	mode sampling PMC measuring hardware events
	     specified in event-spec.

     -R	logfilename
	     Perform offline analysis using sampling data in file logfilename.

     -S	event-spec
	     Allocate a	system mode sampling PMC measuring hardware events
	     specified in event-spec.

     -W	     Toggle logging the	incremental counts seen	by the threads of a
	     tracked process each time they are	scheduled on a CPU.  This is
	     an	experimental feature intended to help analyse the dynamic be-
	     haviour of	processes in the system.  It may incur substantial
	     overhead if enabled.  The default is for this feature to be dis-
	     abled.

     -c	cpu-spec
	     Set the cpus for subsequent system	mode PMCs specified on the
	     command line to cpu-spec.	Argument cpu-spec is a comma separated
	     list of CPU numbers, or the literal `*' denoting all unhalted
	     CPUs.  The	default	is to allocate system mode PMCs	on all
	     unhalted CPUs.

     -d	     Toggle between process mode PMCs measuring	events for the target
	     process' current and future children or only measuring events for
	     the target	process.  The default is to measure events for the
	     target process alone.

     -g	     Produce profiles in a format compatible with gprof(1).  A sepa-
	     rate profile file is generated for	each executable	object encoun-
	     tered.  Profile files are placed in sub-directories named by
	     their PMC event name.

     -k	kerneldir
	     Set the pathname of the kernel directory to argument kerneldir.
	     This directory specifies where pmcstat should look	for the	kernel
	     and its modules.  The default is /boot/kernel.

     -m	pathname
	     Print the sampled PCs with	the name, the start and	ending
	     addresses of the function within they live.  The pathname argu-
	     ment is mandatory and indicates where informations	will be
	     stored.  If argument pathname is a	``-'' this information is sent
	     to	the output file	specified by the -o option.

     -n	rate
	     Set the default sampling rate for subsequent sampling mode	PMCs
	     specified on the command line.  The default is to configure PMCs
	     to	sample the CPU's instruction pointer every 65536 events.

     -o	outputfile
	     Send counter readings and textual representations of logged data
	     to	file outputfile.  The default is to send output	to stderr when
	     collecting	live data and to stdout	when processing	a pre-existing
	     logfile.

     -p	event-spec
	     Allocate a	process	mode counting PMC measuring hardware events
	     specified in event-spec.

     -q	     Decrease verbosity.

     -r	fsroot
	     Set the top of the	filesystem hierarchy under which executables
	     are located to argument fsroot.  The default is /.

     -s	event-spec
	     Allocate a	system mode counting PMC measuring hardware events
	     specified in event-spec.

     -t	process-spec
	     Attach process mode PMCs to the processes named by	argument
	     process-spec.  Argument process-spec may be a non-negative	inte-
	     ger denoting a specific process id, or a regular expression for
	     selecting processes based on their	command	names.

     -v	     Increase verbosity.

     -w	secs
	     Print the values of all counting mode PMCs	every secs seconds.
	     The argument secs may be a	fractional value.  The default inter-
	     val is 5 seconds.

     -z	graphdepth
	     When printing system-wide callgraphs, limit callgraphs to the
	     depth specified by	argument graphdepth.

     If	command	is specified, it is executed using execvp(3).

EXAMPLES
     To	perform	system-wide statistical	sampling on an AMD Athlon CPU with
     samples taken every 32768 instruction retirals and	data being sampled to
     file sample.stat, use:
	   pmcstat -O sample.stat -n 32768 -S k7-retired-instructions

     To	execute	firefox	and measure the	number of data cache misses suffered
     by	it and its children every 12 seconds on	an AMD Athlon, use:
	   pmcstat -d -w 12 -p k7-dc-misses firefox

     To	measure	instructions retired for all processes named ``emacs'' use:
	   pmcstat -t '^emacs$'	-p instructions

     To	measure	instructions retired for processes named ``emacs'' for a
     period of 10 seconds use:
	   pmcstat -t '^emacs$'	-p instructions	sleep 10

     To	count instruction tlb-misses on	CPUs 0 and 2 on	a Intel	Pentium
     Pro/Pentium III SMP system	use:
	   pmcstat -c 0,2 -s p6-itlb-miss

     To	collect	profiling information for a specific process with pid 1234
     based on instruction cache	misses seen by it use:
	   pmcstat -P ic-misses	-t 1234	-O /tmp/sample.out

     To	perform	system-wide sampling on	all configured processors based	on
     processor instructions retired use:
	   pmcstat -S instructions -O /tmp/sample.out
     If	callgraph capture is not desired use:
	   pmcstat -N -S instructions -O /tmp/sample.out

     To	send the generated event log to	a remote machine use:
	   pmcstat -S instructions -O remotehost:port
     On	the remote machine, the	sample log can be collected using nc(1):
	   nc -l remotehost port > /tmp/sample.out

     To	generate gprof(1) compatible profiles from a sample file use:
	   pmcstat -R /tmp/sample.out -g

     To	print a	system-wide profile with callgraphs to file foo.graph use:
	   pmcstat -R /tmp/sample.out -G foo.graph

DIAGNOSTICS
     If	option -v is specified,	pmcstat	may issue the following	diagnostic
     messages:

     #callchain/dubious-frames	The number of callchain	records	that had an
     ``impossible'' value for a	return address.

     #exec handling errors  The	number of exec(2) events in the	log file that
     named executables that could not be analyzed.

     #exec/elf	The number of exec(2) events that named	ELF executables.

     #exec/unknown  The	number of exec(2) events that named executables	with
     unrecognized formats.

     #samples/total  The total number of samples in the	log file.

     #samples/unclaimed	 The number of samples that could not be correlated to
     a known executable	object (i.e., to an executable,	shared library,	the
     kernel or the runtime loader).

     #samples/unknown-object  The number of samples that were associated with
     an	executable with	an unrecognized	object format.

     The pmcstat utility exits 0 on success, and >0 if an error	occurs.

COMPATIBILITY
     Due to the	limitations of the gmon.out file format, gprof(1) compatible
     profiles generated	by the -g option do not	contain	information about
     calls that	cross executable boundaries.  The generated gmon.out files are
     also only meaningful for native executables.

SEE ALSO
     gprof(1), nc(1), execvp(3), pmc(3), pmclog(3), hwpmc(4), pmccontrol(8),
     sysctl(8)

HISTORY
     The pmcstat utility first appeared	in FreeBSD 6.0.	 It is currently under
     development.

AUTHORS
     Joseph Koshy <jkoshy@FreeBSD.org>

BUGS
     The pmcstat utility cannot	yet analyse hwpmc(4) logs generated by non-
     native architectures.

FreeBSD	10.1		      September	19, 2008		  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXAMPLES | DIAGNOSTICS | COMPATIBILITY | SEE ALSO | HISTORY | AUTHORS | BUGS

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