ocount - Event counting tool for Linux
ocount [ options ] [ --system-wide | --process-list
<pids> | --thread-list <tids> | --cpu-list <cpus> | [
command [ args ] ] ]
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.
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'.
- --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.
This man page is current for oprofile-1.4.0.