gprof(1) — Linux manual page

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GPROF(1)                           GNU                          GPROF(1)

NAME         top

       gprof - display call graph profile data

SYNOPSIS         top

       gprof [ -[abcDhilLrsTvwxyz] ] [ -[ACeEfFJnNOpPqQRStZ][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 ... ]

DESCRIPTION         top

       "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.

OPTIONS         top

       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.

       "-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.

FILES         top

       "a.out"
           the namelist and text space.

       "gmon.out"
           dynamic call graph and profile.

       "gmon.sum"
           summarized dynamic call graph and profile.

BUGS         top

       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.

SEE ALSO         top

       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         top

       Copyright (c) 1988-2021 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".

COLOPHON         top

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binutils-2.36.1                2021-02-06                       GPROF(1)

Pages that refer to this page: oprofile(1)sprof(1)perfmonctl(2)profil(3)