gprof
Command Summary
After you have a profile data file `gmon.out', you can run gprof
to interpret the information in it. The gprof
program prints a
flat profile and a call graph on standard output. Typically you would
redirect the output of gprof
into a file with `>'.
You run gprof
like this:
gprof options [executable-file [profile-data-files...]] [> outfile]
Here square-brackets indicate optional arguments.
If you omit the executable file name, the file `a.out' is used. If you give no profile data file name, the file `gmon.out' is used. If any file is not in the proper format, or if the profile data file does not appear to belong to the executable file, an error message is printed.
You can give more than one profile data file by entering all their names after the executable file name; then the statistics in all the data files are summed together.
The following options may be used to selectively include or exclude functions in the output:
-a
gprof
to suppress the printing of
statically declared (private) functions. (These are functions whose
names are not listed as global, and which are not visible outside the
file/function/block where they were defined.) Time spent in these
functions, calls to/from them, etc, will all be attributed to the
function that was loaded directly before it in the executable file.
This option affects both the flat profile and the call graph.
-D
gprof
to ignore symbols which
are not known to be functions. This option will give more accurate
profile data on systems where it is supported (Solaris and HPUX for
example).
-e function_name
gprof
to not print
information about the function function_name (and its
children...) in the call graph. The function will still be listed
as a child of any functions that call it, but its index number will be
shown as `[not printed]'. More than one `-e' option may be
given; only one function_name may be indicated with each `-e'
option.
-E function_name
-E function
option works like the -e
option, but
time spent in the function (and children who were not called from
anywhere else), will not be used to compute the percentages-of-time for
the call graph. More than one `-E' option may be given; only one
function_name may be indicated with each `-E' option.
-f function_name
gprof
to limit the
call graph to the function function_name and its children (and
their children...). More than one `-f' option may be given;
only one function_name may be indicated with each `-f'
option.
-F function_name
-f
option, but
only time spent in the function and its children (and their
children...) will be used to determine total-time and
percentages-of-time for the call graph. More than one `-F' option
may be given; only one function_name may be indicated with each
`-F' option. The `-F' option overrides the `-E' option.
-k from... to...
-v
gprof
to print the current version
number, and then exit.
-z
gprof
will mention all
functions in the flat profile, even those that were never called, and
that had no time spent in them. This is useful in conjunction with the
`-c' option for discovering which routines were never called.
The order of these options does not matter.
Note that only one function can be specified with each -e
,
-E
, -f
or -F
option. To specify more than one
function, use multiple options. For example, this command:
gprof -e boring -f foo -f bar myprogram > gprof.output
lists in the call graph all functions that were reached from either
foo
or bar
and were not reachable from boring
.
There are a few other useful gprof
options:
-b
gprof
doesn't print the
verbose blurbs that try to explain the meaning of all of the fields in
the tables. This is useful if you intend to print out the output, or
are tired of seeing the blurbs.
-c
-d num
-s
gprof
to summarize the information
in the profile data files it read in, and write out a profile data
file called `gmon.sum', which contains all the information from
the profile data files that gprof
read in. The file `gmon.sum'
may be one of the specified input files; the effect of this is to
merge the data in the other input files into `gmon.sum'.
See section Statistical Inaccuracy of gprof
Output.
Eventually you can run gprof
again without `-s' to analyze the
cumulative data in the file `gmon.sum'.
-T
gprof
to print its output in
"traditional" BSD style.
--function-ordering
gprof
to print a
suggested function ordering for the program based on profiling data.
This option suggests an ordering which may improve paging, tlb and
cache behavior for the program on systems which support arbitrary
ordering of functions in an executable.
The exact details of how to force the linker to place functions
in a particular order is system dependent and out of the scope of this
manual.
--file-ordering map_file
gprof
to print a
suggested .o link line ordering for the program based on profiling data.
This option suggests an ordering which may improve paging, tlb and
cache behavior for the program on systems which do not support arbitrary
ordering of functions in an executable.
Use of the `-a' argument is highly recommended with this option.
The map_file argument is a pathname to a file which provides
function name to object file mappings. The format of the file is similar to
the output of the program nm
.
c-parse.o:00000000 T yyparse c-parse.o:00000004 C yyerrflag c-lang.o:00000000 T maybe_objc_method_name c-lang.o:00000000 T print_lang_statistics c-lang.o:00000000 T recognize_objc_keyword c-decl.o:00000000 T print_lang_identifier c-decl.o:00000000 T print_lang_type ...GNU
nm
`--extern-only' `--defined-only' `-v' `--print-file-name' can be used to create map_file.