1.\" Copyright (c) 1983, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)gprof.1 8.1 (Berkeley) 6/6/93 33.\" $FreeBSD$ 34.\" 35.Dd June 6, 1993 36.Dt GPROF 1 37.Os 38.Sh NAME 39.Nm gprof 40.Nd display call graph profile data 41.Sh SYNOPSIS 42.Nm 43.Op Fl abcKlLsuz 44.Op Fl C Ar count 45.Op Fl e Ar name 46.Op Fl E Ar name 47.Op Fl f Ar name 48.Op Fl F Ar name 49.Op Fl k Ar fromname toname 50.Op Ar a.out Op Ar a.out.gmon ... 51.Sh DESCRIPTION 52The 53.Nm 54utility produces an execution profile of C, Pascal, or Fortran77 programs. 55The effect of called routines is incorporated in the profile of each caller. 56The profile data is taken from the call graph profile file 57which is created by programs that are compiled with the 58.Fl pg 59option of 60.Xr cc 1 , 61.Xr pc 1 , 62and 63.Xr f77 1 . 64The 65.Fl pg 66option also links in versions of the library routines 67that are compiled for profiling. 68By convention these libraries have their name suffixed with 69.Pa _p , 70i.e. the profiled version of 71.Pa libc.a 72is 73.Pa libc_p.a 74and if you specify libraries directly to the 75compiler or linker you can use 76.Fl l Ns Ar c_p 77instead of 78.Fl l Ns Ar c . 79Read the given object file (the default is 80.Pa a.out) 81and establishes the relation between its symbol table 82and the call graph profile. 83The default graph profile file name is the name 84of the executable with the suffix 85.Pa .gmon 86appended. 87If more than one profile file is specified, 88the 89.Nm 90output shows the sum of the profile information in the given profile files. 91.Pp 92The 93.Nm 94utility calculates the amount of time spent in each routine. 95Next, these times are propagated along the edges of the call graph. 96Cycles are discovered, and calls into a cycle are made to share the time 97of the cycle. 98The first listing shows the functions 99sorted according to the time they represent 100including the time of their call graph descendants. 101Below each function entry is shown its (direct) call graph children, 102and how their times are propagated to this function. 103A similar display above the function shows how this function's time and the 104time of its descendants is propagated to its (direct) call graph parents. 105.Pp 106Cycles are also shown, with an entry for the cycle as a whole and 107a listing of the members of the cycle and their contributions to the 108time and call counts of the cycle. 109.Pp 110Second, a flat profile is given, 111similar to that provided by 112.Xr prof 1 . 113This listing gives the total execution times, the call counts, 114the time in msec or usec the call spent in the routine itself, and 115the time in msec or usec the call spent in the routine itself including 116its descendants. 117.Pp 118Finally, an index of the function names is provided. 119.Pp 120The following options are available: 121.Bl -tag -width indent 122.It Fl a 123Suppress the printing of statically declared functions. 124If this option is given, all relevant information about the static function 125(e.g., time samples, calls to other functions, calls from other functions) 126belongs to the function loaded just before the static function in the 127.Pa a.out 128file. 129.It Fl b 130Suppress the printing of a description of each field in the profile. 131.It Fl c 132The static call graph of the program is discovered by a heuristic 133that examines the text space of the object file. 134Static-only parents or children are shown 135with call counts of 0. 136This option is not supported on some architectures. 137.It Fl C Ar count 138Find a minimal set of arcs that can be broken to eliminate all cycles with 139.Ar count 140or more members. 141Caution: the algorithm used to break cycles is exponential, 142so using this option may cause 143.Nm 144to run for a very long time. 145.It Fl e Ar name 146Suppress the printing of the graph profile entry for routine 147.Ar name 148and all its descendants 149(unless they have other ancestors that aren't suppressed). 150More than one 151.Fl e 152option may be given. 153Only one 154.Ar name 155may be given with each 156.Fl e 157option. 158.It Fl E Ar name 159Suppress the printing of the graph profile entry for routine 160.Ar name 161(and its descendants) as 162.Fl e , 163above, and also excludes the time spent in 164.Ar name 165(and its descendants) from the total and percentage time computations. 166(For example, 167.Fl E 168.Ar mcount 169.Fl E 170.Ar mcleanup 171is the default.) 172.It Fl f Ar name 173Print the graph profile entry of only the specified routine 174.Ar name 175and its descendants. 176More than one 177.Fl f 178option may be given. 179Only one 180.Ar name 181may be given with each 182.Fl f 183option. 184.It Fl F Ar name 185Print the graph profile entry of only the routine 186.Ar name 187and its descendants (as 188.Fl f , 189above) and also uses only the times of the printed routines 190in total time and percentage computations. 191More than one 192.Fl F 193option may be given. 194Only one 195.Ar name 196may be given with each 197.Fl F 198option. 199The 200.Fl F 201option 202overrides 203the 204.Fl E 205option. 206.It Fl k Ar fromname Ar toname 207Will delete any arcs from routine 208.Ar fromname 209to routine 210.Ar toname . 211This can be used to break undesired cycles. 212More than one 213.Fl k 214option may be given. 215Only one pair of routine names may be given with each 216.Fl k 217option. 218.It Fl K 219Gather information about symbols from the currently-running kernel using the 220.Xr sysctl 3 221and 222.Xr kldsym 2 223interfaces. 224This forces the 225.Pa a.out 226argument to be ignored, and allows for symbols in 227.Xr kld 4 228modules to be used. 229.It Fl l 230Suppress the printing of the call-graph profile. 231.It Fl L 232Suppress the printing of the flat profile. 233.It Fl s 234A profile file 235.Pa gmon.sum 236is produced that represents 237the sum of the profile information in all the specified profile files. 238This summary profile file may be given to later 239executions of gprof (probably also with a 240.Fl s ) 241to accumulate profile data across several runs of an 242.Pa a.out 243file. 244.It Fl u 245Suppress the printing of functions whose names are not visible to 246C programs. For the ELF object format, this means names that 247contain the 248.Ql .\& 249character. For the a.out object format, it means names that do not 250begin with a 251.Ql _ 252character. 253All relevant information about such functions belongs to the 254(non-suppressed) function with the next lowest address. 255This is useful for eliminating "functions" that are just labels 256inside other functions. 257.It Fl z 258Display routines that have zero usage (as shown by call counts 259and accumulated time). 260This is useful with the 261.Fl c 262option for discovering which routines were never called. 263.El 264.Sh FILES 265.Bl -tag -width a.out.gmon -compact 266.It Pa a.out 267The namelist and text space. 268.It Pa a.out.gmon 269Dynamic call graph and profile. 270.It Pa gmon.sum 271Summarized dynamic call graph and profile. 272.El 273.Sh SEE ALSO 274.Xr cc 1 , 275.Xr profil 2 , 276.Xr clocks 7 277.\" .Xr monitor 3 , 278.\" .Xr prof 1 279.Rs 280.%T "An Execution Profiler for Modular Programs" 281.%A S. Graham 282.%A P. Kessler 283.%A M. McKusick 284.%J "Software - Practice and Experience" 285.%V 13 286.%P pp. 671-685 287.%D 1983 288.Re 289.Rs 290.%T "gprof: A Call Graph Execution Profiler" 291.%A S. Graham 292.%A P. Kessler 293.%A M. McKusick 294.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices" 295.%V 17 296.%N 6 297.%P pp. 120-126 298.%D June 1982 299.Re 300.Sh HISTORY 301The 302.Nm 303profiler 304appeared in 305.Bx 4.2 . 306.Sh BUGS 307The granularity of the sampling is shown, but remains 308statistical at best. 309We assume that the time for each execution of a function 310can be expressed by the total time for the function divided 311by the number of times the function is called. 312Thus the time propagated along the call graph arcs to the function's 313parents is directly proportional to the number of times that 314arc is traversed. 315.Pp 316Parents that are not themselves profiled will have the time of 317their profiled children propagated to them, but they will appear 318to be spontaneously invoked in the call graph listing, and will 319not have their time propagated further. 320Similarly, signal catchers, even though profiled, will appear 321to be spontaneous (although for more obscure reasons). 322Any profiled children of signal catchers should have their times 323propagated properly, unless the signal catcher was invoked during 324the execution of the profiling routine, in which case all is lost. 325.Pp 326The profiled program must call 327.Xr exit 3 328or return normally for the profiling information to be saved 329in the graph profile file. 330