Provided by: oprofile_1.4.0-0ubuntu9_amd64 
NAME
ocount - Event counting tool for Linux
SYNOPSIS
ocount [ options ] [ --system-wide | --process-list <pids> | --thread-list <tids> | --cpu-list <cpus> | [
command [ args ] ] ]
DESCRIPTION
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
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
--events / -e event1[,event2[,...]]
This option is for passing a comma-separated list of event specifications for counting. Each event
spec is of the form:
name[:unitmask[:kernel[:user]]]
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 example:
-e INST_RETIRED_ANY_P:0:1:0
^ ^ ^
| | |--- '0': do not count user space events
| |-- '1': count kernel space events
|-- '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 type.
--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 aggregated.
--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 format:
[cpu or thread,]<event_name>[:umask[:K:U]],<count>,<percent_time_enabled>
[ <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
timestamp,<num_seconds_since_epoch>[.n]
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
$ ocount make
VERSION
This man page is current for oprofile-1.4.0.
SEE ALSO
operf(1).
oprofile 1.4.0 Mon 22 April 2024 ocount(1)