1.\" $OpenBSD: gprof.1,v 1.20 2007/05/31 19:20:10 jmc Exp $ 2.\" $NetBSD: gprof.1,v 1.6 1995/11/21 22:24:55 jtc Exp $ 3.\" 4.\" Copyright (c) 1983, 1990, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)gprof.1 8.1 (Berkeley) 6/6/93 32.\" 33.Dd $Mdocdate: May 31 2007 $ 34.Dt GPROF 1 35.Os 36.Sh NAME 37.Nm gprof 38.Nd display call graph profile data 39.Sh SYNOPSIS 40.Nm gprof 41.Bk -words 42.Op Fl abcsz 43.Op Fl C Ar count 44.Op Fl E Ar name 45.Op Fl e Ar name 46.Op Fl F Ar name 47.Op Fl f Ar name 48.Op Fl k Ar from-name to-name 49.Op Ar a.out Op Ar gmon.out ... 50.Ek 51.Sh DESCRIPTION 52.Nm 53produces an execution profile of C, Pascal, or Fortran77 programs. 54The effect of called routines is incorporated in the profile of each caller. 55The profile data is taken from the call graph profile file 56.Pf ( Pa gmon.out 57default) which is created by programs 58that are compiled with the 59.Fl pg 60option of 61.Xr cc 1 , 62.Xr pc , 63and 64.Xr f77 1 . 65The 66.Fl pg 67option also links in versions of the library routines 68that are compiled for profiling. 69.Nm 70reads the given object file (the default is 71.Pa a.out ) 72and establishes the relation between its symbol table 73and the call graph profile from 74.Pa gmon.out . 75If more than one profile file is specified, 76the 77.Nm 78output shows the sum of the profile information in the given profile files. 79.Pp 80.Nm 81calculates the amount of time spent in each routine. 82Next, these times are propagated along the edges of the call graph. 83Cycles are discovered, and calls into a cycle are made to share the time 84of the cycle. 85The first listing shows the functions 86sorted according to the time they represent 87including the time of their call graph descendents. 88Below each function entry is shown its (direct) call graph children, 89and how their times are propagated to this function. 90A similar display above the function shows how this function's time and the 91time of its descendents is propagated to its (direct) call graph parents. 92.Pp 93Cycles are also shown, with an entry for the cycle as a whole and 94a listing of the members of the cycle and their contributions to the 95time and call counts of the cycle. 96.Pp 97Second, a flat profile is given, 98similar to that provided by 99.Xr prof . 100This listing gives the total execution times, the call counts, 101the time in milliseconds the call spent in the routine itself, and 102the time in milliseconds the call spent in the routine itself including 103its descendents. 104.Pp 105Finally, an index of the function names is provided. 106.Pp 107The options are as follows: 108.Bl -tag -width Ds 109.It Fl a 110Suppresses the printing of statically declared functions. 111If this option is given, all relevant information about the static function 112(e.g., time samples, calls to other functions, calls from other functions) 113belongs to the function loaded just before the static function in the 114.Pa a.out 115file. 116.It Fl b 117Suppresses the printing of a description of each field in the profile. 118.It Fl C Ar count 119Find a minimal set of arcs that can be broken to eliminate all cycles with 120.Ar count 121or more members. 122Caution: the algorithm used to break cycles is exponential, 123so using this option may cause 124.Nm 125to run for a very long time. 126.It Fl c 127The static call graph of the program is discovered by a heuristic 128that examines the text space of the object file. 129Static-only parents or children are shown 130with call counts of 0. 131.It Fl E Ar name 132Suppresses the printing of the graph profile entry for routine 133.Ar name 134(and its descendants) as 135.Fl e , 136above, and also excludes the time spent in 137.Ar name 138(and its descendants) from the total and percentage time computations. 139(For example, 140.Fl E 141.Ar mcount 142.Fl E 143.Ar mcleanup 144is the default.) 145.It Fl e Ar name 146Suppresses 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 F Ar name 159Prints the graph profile entry of only the routine 160.Ar name 161and its descendants (as 162.Fl f , 163above) and also uses only the times of the printed routines 164in total time and percentage computations. 165More than one 166.Fl F 167option may be given. 168Only one 169.Ar name 170may be given with each 171.Fl F 172option. 173The 174.Fl F 175option 176overrides 177the 178.Fl E 179option. 180.It Fl f Ar name 181Prints the graph profile entry of only the specified routine 182.Ar name 183and its descendants. 184More than one 185.Fl f 186option may be given. 187Only one 188.Ar name 189may be given with each 190.Fl f 191option. 192.It Fl k Ar from-name Ar to-name 193Will delete any arcs from routine 194.Ar from-name 195to routine 196.Ar to-name . 197This can be used to break undesired cycles. 198More than one 199.Fl k 200option may be given. 201Only one pair of routine names may be given with each 202.Fl k 203option. 204.It Fl s 205A profile file 206.Pa gmon.sum 207is produced that represents 208the sum of the profile information in all the specified profile files. 209This summary profile file may be given to later 210executions of 211.Nm 212(probably also with a 213.Fl s ) 214to accumulate profile data across several runs of an 215.Pa a.out 216file. 217.It Fl z 218Displays routines that have zero usage (as shown by call counts 219and accumulated time). 220This is useful with the 221.Fl c 222option for discovering which routines were never called. 223.El 224.Sh ENVIRONMENT 225.Bl -tag -width PROFDIR 226.It Ev PROFDIR 227Directory to place profiling information in a file named 228.Pa pid.progname . 229If it is set to a null value, no profiling information is output. 230Otherwise, profiling information is placed in the file 231.Pa gmon.out . 232.El 233.Sh FILES 234.Bl -tag -width gmon.sum -compact 235.It Pa a.out 236namelist and text space 237.It Pa gmon.out 238dynamic call graph and profile 239.It Pa gmon.sum 240summarized dynamic call graph and profile 241.El 242.Sh SEE ALSO 243.Xr cc 1 , 244.Xr profil 2 , 245.Xr moncontrol 3 246.Rs 247.%T "An Execution Profiler for Modular Programs" 248.%A S. Graham 249.%A P. Kessler 250.%A M. McKusick 251.%J "Software - Practice and Experience" 252.%V 13 253.%P pp. 671-685 254.%D 1983 255.Re 256.Rs 257.%T "gprof: A Call Graph Execution Profiler" 258.%A S. Graham 259.%A P. Kessler 260.%A M. McKusick 261.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices" 262.%V 17 263.%N 6 264.%P pp. 120-126 265.%D June 1982 266.Re 267.Sh HISTORY 268The 269.Nm 270profiler 271appeared in 272.Bx 4.2 . 273.Sh BUGS 274The granularity of the sampling is shown, but remains 275statistical at best. 276We assume that the time for each execution of a function 277can be expressed by the total time for the function divided 278by the number of times the function is called. 279Thus the time propagated along the call graph arcs to the function's 280parents is directly proportional to the number of times that 281arc is traversed. 282.Pp 283Parents that are not themselves profiled will have the time of 284their profiled children propagated to them, but they will appear 285to be spontaneously invoked in the call graph listing, and will 286not have their time propagated further. 287Similarly, signal catchers, even though profiled, will appear 288to be spontaneous (although for more obscure reasons). 289Any profiled children of signal catchers should have their times 290propagated properly, unless the signal catcher was invoked during 291the execution of the profiling routine, in which case all is lost. 292.Pp 293The profiled program must call 294.Xr exit 3 295or return normally for the profiling information to be saved 296in the 297.Pa gmon.out 298file. 299