*nix Documentation Project
·  Home
 +   man pages
·  Linux HOWTOs
·  FreeBSD Tips
·  *niX Forums

  man pages->FreeBSD man pages -> gprof (1)              



NAME    [Toc]    [Back]

     gprof -- display call graph profile data

SYNOPSIS    [Toc]    [Back]

     gprof [-abcKlLsuz] [-C count] [-e name] [-E name] [-f name] [-F name]
	   [-k fromname toname] [a.out [a.out.gmon ...]]

DESCRIPTION    [Toc]    [Back]

     The gprof utility produces an execution profile of C, Pascal, or Fortran77
 programs.  The effect of called routines is incorporated in the
     profile of each caller.  The profile data is taken from the call graph
     profile file which is created by programs that are compiled with the -pg
     option of cc(1), pc(1), and f77(1).  The -pg option also links in versions
 of the library routines that are compiled for profiling.  By convention
 these libraries have their name suffixed with _p, i.e. the profiled
 version of libc.a is libc_p.a and if you specify libraries directly
     to the compiler or linker you can use -lc_p instead of -lc.  Read the
     given object file (the default is a.out) and establishes the relation
     between its symbol table and the call graph profile.  The default graph
     profile file name is the name of the executable with the suffix .gmon
     appended.	If more than one profile file is specified, the gprof output
     shows the sum of the profile information in the given profile files.

     The gprof utility calculates the amount of time spent in each routine.
     Next, these times are propagated along the edges of the call graph.
     Cycles are discovered, and calls into a cycle are made to share the time
     of the cycle.  The first listing shows the functions sorted according to
     the time they represent including the time of their call graph descendants.
  Below each function entry is shown its (direct) call graph children,
 and how their times are propagated to this function.  A similar
     display above the function shows how this function's time and the time of
     its descendants is propagated to its (direct) call graph parents.

     Cycles are also shown, with an entry for the cycle as a whole and a listing
 of the members of the cycle and their contributions to the time and
     call counts of the cycle.

     Second, a flat profile is given, similar to that provided by prof(1).
     This listing gives the total execution times, the call counts, the time
     in msec or usec the call spent in the routine itself, and the time in
     msec or usec the call spent in the routine itself including its descendants.

     Finally, an index of the function names is provided.

     The following options are available:

     -a      Suppress the printing of statically declared functions.  If this
	     option is given, all relevant information about the static function
 (e.g., time samples, calls to other functions, calls from
	     other functions) belongs to the function loaded just before the
	     static function in the a.out file.

     -b      Suppress the printing of a description of each field in the profile.

     -c      The static call graph of the program is discovered by a heuristic
	     that examines the text space of the object file.  Static-only
	     parents or children are shown with call counts of 0.  This option
	     is not supported on some architectures.

     -C count
	     Find a minimal set of arcs that can be broken to eliminate all
	     cycles with count or more members.  Caution: the algorithm used
	     to break cycles is exponential, so using this option may cause
	     gprof to run for a very long time.

     -e name
	     Suppress the printing of the graph profile entry for routine name
	     and all its descendants (unless they have other ancestors that
	     aren't suppressed).  More than one -e option may be given.  Only
	     one name may be given with each -e option.

     -E name
	     Suppress the printing of the graph profile entry for routine name
	     (and its descendants) as -e, above, and also excludes the time
	     spent in name (and its descendants) from the total and percentage
	     time computations.  (For example, -E mcount -E mcleanup is the

     -f name
	     Print the graph profile entry of only the specified routine name
	     and its descendants.  More than one -f option may be given.  Only
	     one name may be given with each -f option.

     -F name
	     Print the graph profile entry of only the routine name and its
	     descendants (as -f, above) and also uses only the times of the
	     printed routines in total time and percentage computations.  More
	     than one -F option may be given.  Only one name may be given with
	     each -F option.  The -F option overrides the -E option.

     -k fromname toname
	     Will delete any arcs from routine fromname to routine toname.
	     This can be used to break undesired cycles.  More than one -k
	     option may be given.  Only one pair of routine names may be given
	     with each -k option.

     -K      Gather information about symbols from the currently-running kernel
 using the sysctl(3) and kldsym(2) interfaces.	This forces
	     the a.out argument to be ignored, and allows for symbols in
	     kld(4) modules to be used.

     -l      Suppress the printing of the call-graph profile.

     -L      Suppress the printing of the flat profile.

     -s      A profile file gmon.sum is produced that represents the sum of
	     the profile information in all the specified profile files.  This
	     summary profile file may be given to later executions of gprof
	     (probably also with a -s) to accumulate profile data across several
 runs of an a.out file.

     -u      Suppress the printing of functions whose names are not visible to
	     C programs.  For the ELF object format, this means names that
	     contain the `.' character.  For the a.out object format, it means
	     names that do not begin with a `_' character.  All relevant
	     information about such functions belongs to the (non-suppressed)
	     function with the next lowest address.  This is useful for eliminating
 "functions" that are just labels inside other functions.

     -z      Display routines that have zero usage (as shown by call counts
	     and accumulated time).  This is useful with the -c option for
	     discovering which routines were never called.

FILES    [Toc]    [Back]

     a.out	 The namelist and text space.
     a.out.gmon  Dynamic call graph and profile.
     gmon.sum	 Summarized dynamic call graph and profile.

SEE ALSO    [Toc]    [Back]

     cc(1), profil(2), clocks(7)

     S. Graham, P. Kessler, and M. McKusick, "An Execution Profiler for
     Modular Programs", Software - Practice and Experience, 13, pp. 671-685,

     S. Graham, P. Kessler, and M. McKusick, "gprof: A Call Graph Execution
     Profiler", Proceedings of the SIGPLAN '82 Symposium on Compiler
     Construction, SIGPLAN Notices, 6, 17, pp. 120-126, June 1982.

HISTORY    [Toc]    [Back]

     The gprof profiler appeared in 4.2BSD.

BUGS    [Toc]    [Back]

     The granularity of the sampling is shown, but remains statistical at
     best.  We assume that the time for each execution of a function can be
     expressed by the total time for the function divided by the number of
     times the function is called.  Thus the time propagated along the call
     graph arcs to the function's parents is directly proportional to the number
 of times that arc is traversed.

     Parents that are not themselves profiled will have the time of their profiled
 children propagated to them, but they will appear to be spontaneously
 invoked in the call graph listing, and will not have their time
     propagated further.  Similarly, signal catchers, even though profiled,
     will appear to be spontaneous (although for more obscure reasons).  Any
     profiled children of signal catchers should have their times propagated
     properly, unless the signal catcher was invoked during the execution of
     the profiling routine, in which case all is lost.

     The profiled program must call exit(3) or return normally for the profiling
 information to be saved in the graph profile file.

FreeBSD 5.2.1			 June 6, 1993			 FreeBSD 5.2.1
[ Back ]
 Similar pages
Name OS Title
gprof Tru64 Displays call-graph profile data
prof HP-UX display profile data
dprofpp OpenBSD display perl profile data
dprofpp Linux display perl profile data
gcov NetBSD display basic block profile / coverage data
hiprof Tru64 CPU-time and page-fault call-graph profiler for performance analysis
VkMeter IRIX Display a layered bar graph
graph Linux 2D graph for plotting X-Y coordinate data.
prof Tru64 Analyzes profile data
pixstats Tru64 Analyzes profile data
Copyright © 2004-2005 DeniX Solutions SRL
newsletter delivery service