OPERF(1)						      General Commands Manual							  OPERF(1)

NAME

       operf - Performance profiler tool for Linux

SYNOPSIS

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

DESCRIPTION

       Operf  is  an  OProfile	tool  that can be used in place of opcontrol for profiling. Operf uses the Linux Performance Events Subsystem, and
       hence, does not require the use of the opcontrol daemon -- in fact, operf and opcontrol usage are mutually exclusive.

       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.  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>/sam-
       ples directory.

OPTIONS

       command[args]
	      The command or application to be profiled.  args are the input arguments that the command or application requires.   One	(and  only
	      one) of either command , --pid or --system-wide is required.

       --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.

       --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 profil-
	      ing,  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  recom-
	      mended  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.

       --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.

       --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]]]
	      You  can	specify  unit  mask  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.

	      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 appropri-
	      ate 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 exe-
	      cuting 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 --sys-
	      tem-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.

       --append / -a
	      By default, operf moves old profile data from <session_dir>/samples/current to <session_dir>/samples/previous.  If a 'previous' pro-
	      file 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-0.9.9.

SEE ALSO

       opreport(1), opannotate(1).

oprofile 0.9.9							 Tue 10 June 2014							  OPERF(1)