|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | FILES | BUGS | SEE ALSO | COPYRIGHT | COLOPHON |
|
|
|
GPROF(1) GNU GPROF(1)
gprof - display call graph profile data
gprof [ -[abcDhilLrsTvwxyz] ] [ -[ABCeEfFJnNOpPqQRStZ][name] ]
[ -I dirs ] [ -d[num] ] [ -k from/to ]
[ -m min-count ] [ -R map_file ] [ -t table-length ]
[ --[no-]annotated-source[=name] ]
[ --[no-]exec-counts[=name] ]
[ --[no-]flat-profile[=name] ] [ --[no-]graph[=name] ]
[ --[no-]time=name] [ --all-lines ] [ --brief ]
[ --debug[=level] ] [ --function-ordering ]
[ --file-ordering map_file ] [ --directory-path=dirs ]
[ --display-unused-functions ] [ --file-format=name ]
[ --file-info ] [ --help ] [ --line ] [ --inline-file-names ]
[ --min-count=n ] [ --no-static ] [ --print-path ]
[ --separate-files ] [ --static-call-graph ] [ --sum ]
[ --table-length=len ] [ --traditional ] [ --version ]
[ --width=n ] [ --ignore-non-functions ]
[ --demangle[=STYLE] ] [ --no-demangle ]
[--external-symbol-table=name]
[ image-file ] [ profile-file ... ]
"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 that are compiled with the -pg option of "cc", "pc", and
"f77". The -pg option also links in versions of the library
routines that are compiled for profiling. "Gprof" reads the
given object file (the default is "a.out") and establishes the
relation between its symbol table and the call graph profile from
gmon.out. If more than one profile file is specified, the
"gprof" output shows the sum of the profile information in the
given profile files.
"Gprof" 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.
Several forms of output are available from the analysis.
The flat profile shows how much time your program spent in each
function, and how many times that function was called. If you
simply want to know which functions burn most of the cycles, it
is stated concisely here.
The call graph shows, for each function, which functions called
it, which other functions it called, and how many times. There
is also an estimate of how much time was spent in the subroutines
of each function. This can suggest places where you might try to
eliminate function calls that use a lot of time.
The annotated source listing is a copy of the program's source
code, labeled with the number of times each line of the program
was executed.
These options specify which of several output formats "gprof"
should produce.
Many of these options take an optional symspec to specify
functions to be included or excluded. These options can be
specified multiple times, with different symspecs, to include or
exclude sets of symbols.
Specifying any of these options overrides the default (-p -q),
which prints a flat profile and call graph analysis for all
functions.
"-A[symspec]"
"--annotated-source[=symspec]"
The -A option causes "gprof" to print annotated source code.
If symspec is specified, print output only for matching
symbols.
"-b"
"--brief"
If the -b option is given, "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.
"-B"
The -B option causes "gprof" to print the call graph
analysis.
"-C[symspec]"
"--exec-counts[=symspec]"
The -C option causes "gprof" to print a tally of functions
and the number of times each was called. If symspec is
specified, print tally only for matching symbols.
If the profile data file contains basic-block count records,
specifying the -l option, along with -C, will cause basic-
block execution counts to be tallied and displayed.
"-i"
"--file-info"
The -i option causes "gprof" to display summary information
about the profile data file(s) and then exit. The number of
histogram, call graph, and basic-block count records is
displayed.
"-I dirs"
"--directory-path=dirs"
The -I option specifies a list of search directories in which
to find source files. Environment variable GPROF_PATH can
also be used to convey this information. Used mostly for
annotated source output.
"-J[symspec]"
"--no-annotated-source[=symspec]"
The -J option causes "gprof" not to print annotated source
code. If symspec is specified, "gprof" prints annotated
source, but excludes matching symbols.
"-L"
"--print-path"
Normally, source filenames are printed with the path
component suppressed. The -L option causes "gprof" to print
the full pathname of source filenames, which is determined
from symbolic debugging information in the image file and is
relative to the directory in which the compiler was invoked.
"-p[symspec]"
"--flat-profile[=symspec]"
The -p option causes "gprof" to print a flat profile. If
symspec is specified, print flat profile only for matching
symbols.
"-P[symspec]"
"--no-flat-profile[=symspec]"
The -P option causes "gprof" to suppress printing a flat
profile. If symspec is specified, "gprof" prints a flat
profile, but excludes matching symbols.
"-q[symspec]"
"--graph[=symspec]"
The -q option causes "gprof" to print the call graph
analysis. If symspec is specified, print call graph only for
matching symbols and their children.
"-Q[symspec]"
"--no-graph[=symspec]"
The -Q option causes "gprof" to suppress printing the call
graph. If symspec is specified, "gprof" prints a call graph,
but excludes matching symbols.
"-t"
"--table-length=num"
The -t option causes the num most active source lines in each
source file to be listed when source annotation is enabled.
The default is 10.
"-y"
"--separate-files"
This option affects annotated source output only. Normally,
"gprof" prints annotated source files to standard-output. If
this option is specified, annotated source for a file named
path/filename is generated in the file filename-ann. If the
underlying file system would truncate filename-ann so that it
overwrites the original filename, "gprof" generates annotated
source in the file filename.ann instead (if the original file
name has an extension, that extension is replaced with .ann).
"-Z[symspec]"
"--no-exec-counts[=symspec]"
The -Z option causes "gprof" not to print a tally of
functions and the number of times each was called. If
symspec is specified, print tally, but exclude matching
symbols.
"-r"
"--function-ordering"
The --function-ordering option causes "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.
"-R map_file"
"--file-ordering map_file"
The --file-ordering option causes "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
...
To create a map_file with GNU "nm", type a command like "nm
--extern-only --defined-only -v --print-file-name
program-name".
"-T"
"--traditional"
The -T option causes "gprof" to print its output in
"traditional" BSD style.
"-w width"
"--width=width"
Sets width of output lines to width. Currently only used
when printing the function index at the bottom of the call
graph.
"-x"
"--all-lines"
This option affects annotated source output only. By
default, only the lines at the beginning of a basic-block are
annotated. If this option is specified, every line in a
basic-block is annotated by repeating the annotation for the
first line. This behavior is similar to "tcov"'s -a.
"--demangle[=style]"
"--no-demangle"
These options control whether C++ symbol names should be
demangled when printing output. The default is to demangle
symbols. The "--no-demangle" option may be used to turn off
demangling. Different compilers have different mangling
styles. The optional demangling style argument can be used
to choose an appropriate demangling style for your compiler.
Analysis Options
"-a"
"--no-static"
The -a option causes "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.
"-c"
"--static-call-graph"
The -c option causes the call graph of the program to be
augmented by a heuristic which examines the text space of the
object file and identifies function calls in the binary
machine code. Since normal call graph records are only
generated when functions are entered, this option identifies
children that could have been called, but never were. Calls
to functions that were not compiled with profiling enabled
are also identified, but only if symbol table entries are
present for them. Calls to dynamic library routines are
typically not found by this option. Parents or children
identified via this heuristic are indicated in the call graph
with call counts of 0.
"-D"
"--ignore-non-functions"
The -D option causes "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).
"-k from/to"
The -k option allows you to delete from the call graph any
arcs from symbols matching symspec from to those matching
symspec to.
"-l"
"--line"
The -l option enables line-by-line profiling, which causes
histogram hits to be charged to individual source code lines,
instead of functions. This feature only works with programs
compiled by older versions of the "gcc" compiler. Newer
versions of "gcc" are designed to work with the "gcov" tool
instead.
If the program was compiled with basic-block counting
enabled, this option will also identify how many times each
line of code was executed. While line-by-line profiling can
help isolate where in a large function a program is spending
its time, it also significantly increases the running time of
"gprof", and magnifies statistical inaccuracies.
"--inline-file-names"
This option causes "gprof" to print the source file after
each symbol in both the flat profile and the call graph. The
full path to the file is printed if used with the -L option.
"-m num"
"--min-count=num"
This option affects execution count output only. Symbols
that are executed less than num times are suppressed.
"-nsymspec"
"--time=symspec"
The -n option causes "gprof", in its call graph analysis, to
only propagate times for symbols matching symspec.
"-Nsymspec"
"--no-time=symspec"
The -n option causes "gprof", in its call graph analysis, not
to propagate times for symbols matching symspec.
"-Sfilename"
"--external-symbol-table=filename"
The -S option causes "gprof" to read an external symbol table
file, such as /proc/kallsyms, rather than read the symbol
table from the given object file (the default is "a.out").
This is useful for profiling kernel modules.
"-z"
"--display-unused-functions"
If you give the -z option, "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.
Miscellaneous Options
"-d[num]"
"--debug[=num]"
The -d num option specifies debugging options. If num is not
specified, enable all debugging.
"-h"
"--help"
The -h option prints command line usage.
"-Oname"
"--file-format=name"
Selects the format of the profile data files. Recognized
formats are auto (the default), bsd, 4.4bsd, magic, and prof
(not yet supported).
"-s"
"--sum"
The -s option causes "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.
Eventually you can run "gprof" again without -s to analyze
the cumulative data in the file gmon.sum.
"-v"
"--version"
The -v flag causes "gprof" to print the current version
number, and then exit.
Deprecated Options
These options have been replaced with newer versions that use
symspecs.
"-e function_name"
The -e function option tells "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"
The "-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"
The -f function option causes "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"
The -F function option works like the "-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.
"a.out"
the namelist and text space.
"gmon.out"
dynamic call graph and profile.
"gmon.sum"
summarized dynamic call graph and profile.
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"(2) or return normally for
the profiling information to be saved in the gmon.out file.
monitor(3), profil(2), cc(1), prof(1), and the Info entry for
gprof.
"An Execution Profiler for Modular Programs", by S. Graham, P.
Kessler, M. McKusick; Software - Practice and Experience, Vol.
13, pp. 671-685, 1983.
"gprof: A Call Graph Execution Profiler", by S. Graham, P.
Kessler, M. McKusick; Proceedings of the SIGPLAN '82 Symposium on
Compiler Construction, SIGPLAN Notices, Vol. 17, No 6, pp.
120-126, June 1982.
Copyright (c) 1988-2024 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License,
Version 1.3 or any later version published by the Free Software
Foundation; with no Invariant Sections, with no Front-Cover
Texts, and with no Back-Cover Texts. A copy of the license is
included in the section entitled "GNU Free Documentation
License".
This page is part of the binutils (a collection of tools for
working with executable binaries) project. Information about the
project can be found at ⟨http://www.gnu.org/software/binutils/⟩.
If you have a bug report for this manual page, see
⟨http://sourceware.org/bugzilla/enter_bug.cgi?product=binutils⟩.
This page was obtained from the tarball binutils-2.42.tar.gz
fetched from ⟨https://ftp.gnu.org/gnu/binutils/⟩ on 2024-06-14.
If you discover any rendering problems in this HTML version of
the page, or you believe there is a better or more up-to-date
source for the page, or you have corrections or improvements to
the information in this COLOPHON (which is not part of the
original manual page), send a mail to man-pages@man7.org
binutils-2.42 2024-01-29 GPROF(1)
Pages that refer to this page: oprofile(1), sprof(1), perfmonctl(2), profil(3)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|