gprof(1) Unsupported gprof(1)Namegprof - display call graph profile data
Syntaxgprof [options] [a.out[gmon.out...]]
Description
The command 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 and 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 output shows the sum of the profile information in the given pro‐
file files.
First, a flat profile is given, similar to that provided by This list‐
ing 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 accord‐
ing 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
The following options are available:
-a Suppresses the printing of statically declared
functions. If this option is given, all relevant
information about the static function (for example,
time samples, calls to other functions, calls from
other functions) belongs to the function loaded
just before the static function in the file.
-b Suppresses the printing of a description of each
field in the profile.
-c The static call graph of the program is discovered
by a 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 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.)
-e name Suppresses the printing of the graph profile entry
for routine name and all its descendants More than
one -e option may be given. Only one name may be
given with each -e 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.
-f name Prints the graph profile entry of only the speci‐
fied routine name and its descendants. More than
one -f option may be given. Only one name may be
given with each -f option.
-s Produces a profile file gmon.sum is produced which
represents the sum of the profile information in
all the specified profile files. This summary pro‐
file file may be given to subsequent executions of
gprof (probably also with a -s) to accumulate pro‐
file data across several runs of an a.out file.
-z Displays routines which have zero usage (as indi‐
cated by call counts and accumulated time). This
is useful in conjunction with the -c option for
discovering which routines were never called.
Restrictions
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 func‐
tion is directly proportional to the number of times that arc is tra‐
versed.
Parents which are not themselves profiled have the time of their pro‐
filed children propagated to them, but they appear to be spontaneously
invoked in the call graph listing, and do not have their time propa‐
gated further. Similarly, signal catchers, even though profiled,
appear to be spontaneous (although for more obscure reasons). Any pro‐
filed 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 or return normally for the profiling
information to be saved in the file.
Files
the name list and text space.
dynamic call graph and profile.
summarized dynamic call graph and profile.
See Alsocc(1), prof(1), profil(2), monitor(3)
VAX gprof(1)