Provided by: oprofile_1.2.0-0ubuntu6_amd64 bug

NAME

       operf - Performance profiler tool for Linux

SYNOPSIS

       operf [ options ] [ --system-wide | --pid <pid> | [ command [ args ] ] ]

DESCRIPTION

       Operf is the profiler tool provided with OProfile. Operf uses the Linux Performance Events
       Subsystem and, thus, does not require the obsolete oprofile kernel driver.

       By default, operf uses <current_dir>/oprofile_data as the session-dir and stores profiling
       data  there.   You  can  change  this  by way of the --session-dir option. The usual post-
       profiling analysis tools such as opreport(1) and opannotate(1) can  be  used  to  generate
       profile  reports.  Unless  a  session-dir is specified, the post-processing analysis tools
       will search for samples in <current_dir>/oprofile_data first. If that directory  does  not
       exist, the post-processing tools use the standard session-dir of /var/lib/oprofile.

       Statistics,  such as total samples received and lost samples, are written to the operf.log
       file that can be found in the <session_dir>/samples directory.

RUN MODES

       One (and only one) of the following run modes must be specified:

       command[args]
              The command or application to be profiled.  args are the input arguments  that  the
              command or application requires.

       --pid / -p PID
              This  option  enables  operf  to  profile a running application.  PID should be the
              process ID of the process you wish to profile.  When finished profiling (e.g., when
              the profiled process ends), press Ctrl-c to stop operf. If you run operf --pid as a
              background job (i.e., with the &), you must stop it in a controlled manner in order
              for  it to process the profile data it has collected.  Use kill -SIGINT <operf-PID>
              for this purpose.

              Limitation: When using this option to profile  a  multi-threaded  application  that
              also  forks  new  processes,  be  aware  that samples for processes that are forked
              before profiling is started may not be recorded  (depending  on  timing  of  thread
              creation and when operf is started).

       --system-wide / -s
              This  option is for performing a system-wide profile.  You must have root authority
              to run operf in this mode.  When finished profiling, Ctrl-c to stop operf.  If  you
              run operf --system-wide as a background job (i.e., with the &), you must stop it in
              a controlled manner in order for it to process the profile data it  has  collected.
              Use kill -SIGINT <operf-PID> for this purpose.  It is recommended that when running
              operf with this option, the user's current working directory should be /root  or  a
              subdirectory of /root to avoid storing sample data files in locations accessible by
              regular users.

OTHER OPTIONS

       --vmlinux / -k vmlinux_path
              A vmlinux file that matches the running kernel that has  symbol  and/or  debuginfo.
              Kernel  samples  will  be attributed to this binary, allowing post-processing tools
              (like opreport) to attribute samples to the appropriate kernel symbols.

              The kernel symbol information may be obtained from /proc/kallsyms if the user  does
              not  specify  a  vmlinux file.  The symbol addresses are given in /proc/kallsyms if
              permitted by the setting of /proc/sys/kernel/kptr_restrict.

              If the --vmlinux option is not used and kernel  symbols  cannot  be  obtained  from
              /proc/kallsyms,  then  all  kernel samples are attributed to "no-vmlinux", which is
              simply a bucket to hold the samples and not an actual file.

       --events / -e event1[,event2[,...]]
              This option is for passing a  comma-separated  list  of  event  specifications  for
              profiling. Each event spec is of the form:
                 name:count[:unitmask[:kernel[:user]]]

              The  count  value  is  used  to  control the sampling rate for profiling; it is the
              number of events to occur between samples. The rate  is  lowered  by  specifying  a
              higher count value — i.e., a higher number of events to occur between samples.

              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 collect samples for kernel space and user space.
              Note: In order to specify the kernel/user bits, you must also  specify  a  unitmask
              value,  even if the processor type (or the specified event) 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:100000:0:1:0
                                       ^      ^ ^ ^
                                       |      | | |--- '0': do not record user space samples
                                       |      | |-- '1': record kernel space samples
                                       |      |-- '0': the null unit mask
                                       |--count value

              Event names for some IBM PowerPC systems include a _GRP<n> (group  number)  suffix.
              You  can  pass either the full event name or the base event name (i.e., without the
              suffix) to operf.  If the base event  name  is  passed,  operf  will  automatically
              choose  an  appropriate  group  number  suffix  for the event; thus, OProfile post-
              processing tools will always show real event names that include  the  group  number
              suffix.   When  no  event specification is given, the default event for the running
              processor type will be used for profiling.  Use ophelp to list the available events
              for your processor type.

       --callgraph / -g
              This  option  enables  the  callgraph  to be saved during profiling. NOTE: The full
              callchain is recorded, so there is no depth limit.

       --separate-thread / -t
              This option categorizes samples by thread group ID (tgid) and thread ID (tid).  The
              '--separate-thread'  option  is  useful  for  seeing  per-thread  samples in multi-
              threaded applications.  When used in conjunction with the  '--system-wide'  option,
              the  '--separate-thread'  option  is also useful for seeing per-process (i.e., per-
              thread group) samples for the case where multiple processes are executing the  same
              program during a profiling run.

       --separate-cpu / -c
              This option categorizes samples by cpu.

       --session-dir / -d path
              This  option  specifies the session path to hold the sample data. If not specified,
              the data is saved in the oprofile_data directory on the current path.

       --lazy-conversion / -l
              Use this option to reduce the overhead of operf during profiling. Normally, profile
              data  received  from  the  kernel  is converted to OProfile format during profiling
              time. This is typically not an issue when profiling a single application. But  when
              using  the  --system-wide  option,  this  on-the-fly  conversion  process can cause
              noticeable overhead, particularly on  busy  multi-processor  systems.  The  --lazy-
              conversion  option  directs  operf  to  wait until profiling is completed to do the
              conversion of profile data.

              Note: This option is not recommended to be  used  in  conjunction  with  the  --pid
              option  for  profiling  multi-threaded  processes. Depending on the order of thread
              creation (or forking of new processes), you may not get any  samples  for  the  new
              threads/processes.

       --append / -a
              By  default,  operf  moves  old  profile data from <session_dir>/samples/current to
              <session_dir>/samples/previous.  If a 'previous' profile already existed,  it  will
              be  replaced.   If the --append option is passed, old profile data is left in place
              and new profile data will be added to  it,  and  the  'previous'  profile  (if  one
              existed)  will  remain  untouched.   To access the 'previous' profile, simply add a
              session specification to the normal invocation of oprofile  post-processing  tools.
              For example:
                 opreport session:previous

       --verbose / -V level
              A  comma-separated list of debugging control values, used to increase the verbosity
              of the output.  Valid values are:  debug, record, convert, misc,  sfile,  arcs,  or
              the special value, 'all'.

       --version / -v
              Show operf version.

       --help / -h
              Display brief usage message.

       --usage / -u
              Display brief usage message.

EXAMPLE

       $ operf make

VERSION

       This man page is current for oprofile-1.2.0.

SEE ALSO

       opreport(1), opannotate(1).