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

     pmcstat - performance measurement with performance monitoring hardware

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

     The pmcstat utility measures system performance using the facilities
     provided 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
     executing on the system's CPUs.  If a specific set of processes is being
     targeted (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
     measurement, 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
     overhead, 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.

     The following options are available:

     -C      Toggle between showing cumulative or incremental counts for
             subsequent 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

     -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
             characteristics of a complex pipeline of processes when used in
             conjunction with the -d option.  The default is to not to enable
             per-process tracking.

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

     -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
             behaviour of processes in the system.  It may incur substantial
             overhead if enabled.  The default is for this feature to be

     -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 CPUs.  The
             default is to allocate system mode PMCs on all 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 flat execution profiles in a format compatible with
             gprof(1).  A separate profile file is generated for each
             executable object encountered.  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.

     -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.

     -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
             integer 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
             interval is 5 seconds.

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

     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 mozilla 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 mozilla

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

     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 perform system-wide sampling on all configured processors based on
     processor instructions retired use:
           pmcstat -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 flat profiles from a sample file use:
           pmcstat -R /tmp/sample.out -g

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

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

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

     Joseph Koshy <>

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

FreeBSD 11.0-PRERELEASE         April 23, 2007         FreeBSD 11.0-PRERELEASE


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