ocount(1) — Linux manual page


ocount(1)                General Commands Manual               ocount(1)

NAME         top

       ocount - Event counting tool for Linux

SYNOPSIS         top

       ocount [ options ] [ --system-wide | --process-list <pids> |
       --thread-list <tids> | --cpu-list <cpus> | [ command [ args ] ] ]

DESCRIPTION         top

       ocount is an OProfile tool that can be used to count native
       hardware events occurring in either a given application, a set of
       processes or threads, a subset of active system processors, or
       the entire system. The data collected during a counting session
       is displayed to stdout by default or, optionally, to a file.

       When counting multiple events, the kernel may not be able to
       count all events simultaneously and, thus, may need to multiplex
       the counting of the events.  If this happens, the "Percent time
       enabled" column in the ocount output will be less than 100, but
       counts are scaled up to a 100% estimated value.

RUN MODES         top

       One (and only one) of the following run modes must be specified.
       If you run ocount using a run mode other than command [args] ,
       press Ctrl-c to stop ocount when finished counting (e.g., when
       the monitored process ends).  If you background ocount (i.e.,
       with '&') while using one these run modes, you must stop it in a
       controlled manner so that the data collection process can be shut
       down cleanly and final results can be displayed. Use kill -SIGINT
       <ocount-PID> for this purpose.

       command [args]
              The command is the application for which to count events.
              args are the input arguments required by the application.
              The command and its arguments must be positioned at the
              end of the command line, after all ocount options.

       --process-list / -p pids
              Use this option to count events for one or more already-
              running applications, specified via a comma-separated list
              ( pids ). Event counts will be collected for all children
              of the passed process(es) as well. You must have
              privileges for the user ID under which the specified
              process(es) are running; e.g., for a non-root user, the
              user ID of the process(es) is the same as that used for
              running ocount. A lack of privileges will result in the
              following failure message:
                      perf_event_open failed with Permission denied

       --thread-list / -r tids
              Use this option to count events for one or more already-
              running threads, specified via a comma-separated list (
              tids ). Event counts will not be collected for any
              children of the passed thread(s). See the description of
              --process-list concerning required privileges.

       --system-wide / -s
              This option is for counting events for all processes
              running on your system.  You must have root authority to
              run ocount in this mode.

       --cpu-list / -C cpus
              This option is for counting events on a subset of
              processors on your system. You must have root authority to
              run ocount in this mode. This is a comma-separated list,
              where each element in the list may be either a single
              processor number or a range of processor numbers; for
              example: '-C 2,3,4-11,15'.

OTHER OPTIONS         top

       --events / -e event1[,event2[,...]]
              This option is for passing a comma-separated list of event
              specifications for counting. Each event spec is of the
              Note: Do not include a count value in the event spec, as
              that parameter is only needed when profiling.

              You can specify unitmask values using either a numerical
              value (hex values must begin with "0x") or a symbolic name
              (if the name=<um_name> field is shown in the ophelp
              output). For some named unit masks, the hex value is not
              unique; thus, OProfile tools enforce specifying such unit
              masks value by name.  If no unit mask is specified, the
              default unit mask value for the event is used.

              The kernel and user parts of the event specification are
              binary values ('1' or '0') indicating whether or not to
              count events in kernel space and user space.
              Note: In order to specify the kernel/user bits, you must
              also specify a unitmask value, even if the running
              processor type does not use unit masks — in which case,
              use the value '0' to signify a null unit mask; for
                 -e INST_RETIRED_ANY_P:0:1:0
                                       ^ ^ ^
                                       | | |--- '0': do not count user
              space events
                                       | |-- '1': count kernel space
                                       |-- '0': the null unit mask

              Event names for certain processor types include a _GRP<n>
              suffix.  For such cases, the --events option may be
              specified with or without the _GRP<n> suffix.

              When no event specification is given, the default event
              for the running processor type will be used for counting.
              Use ophelp to list the available events for your processor

       --separate-thread / -t
              This option can be used in conjunction with either the
              --process-list or --thread-list option to display event
              counts on a per-thread (per-process) basis.  Without this
              option, all counts are aggregated.

              NOTE: If new threads are started by the process(es) being
              monitored after counting begins, the counts for those
              threads are aggregated with their parent's counts.

       --separate-cpu / -c
              This option can be used in conjunction with either the
              --system-wide or --cpu-list option to display event counts
              on a per-cpu basis.  Without this option, all counts are

       --time-interval / -i interval_length[:num_intervals]

              Note: The interval_length is given in milliseconds.
              However, the current implementation only supports 100 ms
              granularity, so the given interval_length will be rounded
              to the nearest 100 ms.  Results collected for each time
              interval are printed immediately instead of the default of
              one dump of cumulative event counts at the end of the run.
              Counters are reset to zero at the start of each interval.

              If num_intervals is specified, ocount exits after the
              specified number of intervals occur.

       --brief-format / -b
              Use this option to print results in the following brief
                  [cpu or
                  [    <u32>    ,]<  string  >[< u32>[<bb>]],< u64 >,<
              double       >

              The umask, Kernel and User modes are only printed if the
              values were specified as part of the event.  The 'K' and
              'U' fields are binary fields separated by colons, where
              the value for each binary field may be either '0' or '1'.

              If --timer-interval is specified, a separate line
              formatted as
              is printed ahead of each dump of event counts. If the time
              interval specified is less than one second, the timestamp
              will have 1/10 second precision.

       --output-file / -f outfile_name
              Results are written to outfile_name instead of
              interactively to the terminal.

       --verbose / -V
              Use this option to increase the verbosity of the output.

       --version / -v
              Show ocount version.

       --help / -h
              Display brief usage message.

       --usage / -u
              Display brief usage message.

EXAMPLE         top

       $ ocount make

VERSION         top

       This man page is current for oprofile-1.5.0git.

SEE ALSO         top


COLOPHON         top

       This page is part of the oprofile (a system-wide profiler for
       Linux) project.  Information about the project can be found at 
       ⟨http://oprofile.sourceforge.net/news/⟩.  If you have a bug report
       for this manual page, see
       ⟨http://oprofile.sourceforge.net/bugs/⟩.  This page was obtained
       from the project's upstream Git repository
       ⟨git://git.code.sf.net/p/oprofile/oprofile⟩ on 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2021-11-29.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

oprofile 1.5.0git         Fri 22 December 2023                 ocount(1)

Pages that refer to this page: oprofile(1)