GPROF(1) COMMAND REFERENCE GPROF(1)
NAME
gprof - display call graph profile data
SYNOPSIS
gprof [ options ] [ a.out [ gmon.out ... ] ]
DESCRIPTION
gprof 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 (gmon.out
default) which is created by programs which are compiled
with the -pg option of cc, pc, and f77. That option also
links in versions of the library routines which are compiled
for profiling. The symbol table in the named object file
(a.out default) is read and correlated with the call graph
profile file. If more than one profile file is specified,
the gprof output shows the sum of the profile information in
the given profile files.
First, a flat profile is given, similar to that provided by
prof(1). This listing gives the total execution times and
call counts for each of the functions in the program, sorted
by decreasing time.
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. A second listing shows
the functions sorted according to the time they represent
including the time of their call graph descendents. 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 descendents 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.
OPTIONS
-a suppresses 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 supresses the printing of a description of each field
in the profile.
-c the static call graph of the program is discovered by a
Printed 10/17/86 1
GPROF(1) COMMAND REFERENCE GPROF(1)
heuristic which examines the text space of the object
file. Static-only parents or children are indicated
with call counts of 0.
-e name
suppresses 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
suppresses 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 default.)
-f name
prints 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
prints 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.
-s a profile file gmon.sum is produced which represents
the sum of the profile information in all the specified
profile files. This summary profile file may be given
to subsequent executions of gprof (probably also with a
-s) to accumulate profile data across several runs of
an a.out file.
-z displays routines which have zero usage (as indicated
by call counts and accumulated time). This is useful
in conjunction with the -c option for discovering which
routines were never called.
FILES
a.out namelist and text space
gmon.out dynamic call graph and profile
gmon.sum summarized dynamic call graph and
profile
Printed 10/17/86 2
GPROF(1) COMMAND REFERENCE GPROF(1)
CAVEATS
Beware of quantization errors. 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 parents of that
function is directly proportional to the number of times
that arc is traversed.
Parents which 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(3c) or return normally
for the profiling information to be saved in the gmon.out
file.
SEE ALSO
monitor(3c), profil(2), cc(1), prof(1).
Printed 10/17/86 3
%%index%%
na:72,75;
sy:147,138;
de:285,1942;
op:2227,608;2979,2431;
fi:5410,291;
ca:5845,1261;
se:7106,169;
%%index%%000000000131