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 options 44.Op Ar a.out Op Ar a.out.gmon ... 45.Sh DESCRIPTION 46The 47.Nm 48utility produces an execution profile of C, Pascal, or Fortran77 programs. 49The effect of called routines is incorporated in the profile of each caller. 50The profile data is taken from the call graph profile file 51which is created by programs that are compiled with the 52.Fl pg 53option of 54.Xr cc 1 , 55.Xr pc 1 , 56and 57.Xr f77 1 . 58The 59.Fl pg 60option also links in versions of the library routines 61that are compiled for profiling. 62By convention these libraries have their name suffixed with 63.Pa _p , 64i.e. the profiled version of 65.Pa libc.a 66is 67.Pa libc_p.a 68and if you specify libraries directly to the 69compiler or linker you can use 70.Fl l Ns Ar c_p 71instead of 72.Fl l Ns Ar c . 73Read the given object file (the default is 74.Pa a.out) 75and establishes the relation between its symbol table 76and the call graph profile. 77The default graph profile file name is the name 78of the executable with the suffix 79.Pa .gmon 80appended. 81If more than one profile file is specified, 82the 83.Nm 84output shows the sum of the profile information in the given profile files. 85.Pp 86The 87.Nm 88utility calculates the amount of time spent in each routine. 89Next, these times are propagated along the edges of the call graph. 90Cycles are discovered, and calls into a cycle are made to share the time 91of the cycle. 92The first listing shows the functions 93sorted according to the time they represent 94including the time of their call graph descendents. 95Below each function entry is shown its (direct) call graph children, 96and how their times are propagated to this function. 97A similar display above the function shows how this function's time and the 98time of its descendents is propagated to its (direct) call graph parents. 99.Pp 100Cycles are also shown, with an entry for the cycle as a whole and 101a listing of the members of the cycle and their contributions to the 102time and call counts of the cycle. 103.Pp 104Second, a flat profile is given, 105similar to that provided by 106.Xr prof 1 . 107This listing gives the total execution times, the call counts, 108the time in msec or usec the call spent in the routine itself, and 109the time in msec or usec the call spent in the routine itself including 110its descendents. 111.Pp 112Finally, an index of the function names is provided. 113.Pp 114The following options are available: 115.Bl -tag -width Fl 116.It Fl a 117Suppresses the printing of statically declared functions. 118If this option is given, all relevant information about the static function 119(e.g., time samples, calls to other functions, calls from other functions) 120belongs to the function loaded just before the static function in the 121.Pa a.out 122file. 123.It Fl b 124Suppresses the printing of a description of each field in the profile. 125.It Fl c 126The static call graph of the program is discovered by a heuristic 127that examines the text space of the object file. 128Static-only parents or children are shown 129with call counts of 0. 130This option is not supported on some architectures. 131.It Fl C Ar count 132Find a minimal set of arcs that can be broken to eliminate all cycles with 133.Ar count 134or more members. 135Caution: the algorithm used to break cycles is exponential, 136so using this option may cause 137.Nm 138to run for a very long time. 139.It Fl e Ar name 140Suppresses the printing of the graph profile entry for routine 141.Ar name 142and all its descendants 143(unless they have other ancestors that aren't suppressed). 144More than one 145.Fl e 146option may be given. 147Only one 148.Ar name 149may be given with each 150.Fl e 151option. 152.It Fl E Ar name 153Suppresses the printing of the graph profile entry for routine 154.Ar name 155(and its descendants) as 156.Fl e , 157above, and also excludes the time spent in 158.Ar name 159(and its descendants) from the total and percentage time computations. 160(For example, 161.Fl E 162.Ar mcount 163.Fl E 164.Ar mcleanup 165is the default.) 166.It Fl f Ar name 167Prints the graph profile entry of only the specified routine 168.Ar name 169and its descendants. 170More than one 171.Fl f 172option may be given. 173Only one 174.Ar name 175may be given with each 176.Fl f 177option. 178.It Fl F Ar name 179Prints the graph profile entry of only the routine 180.Ar name 181and its descendants (as 182.Fl f , 183above) and also uses only the times of the printed routines 184in total time and percentage computations. 185More than one 186.Fl F 187option may be given. 188Only one 189.Ar name 190may be given with each 191.Fl F 192option. 193The 194.Fl F 195option 196overrides 197the 198.Fl E 199option. 200.It Fl k Ar fromname Ar toname 201Will delete any arcs from routine 202.Ar fromname 203to routine 204.Ar toname . 205This can be used to break undesired cycles. 206More than one 207.Fl k 208option may be given. 209Only one pair of routine names may be given with each 210.Fl k 211option. 212.It Fl K 213Gather information about symbols from the currently-running kernel using the 214.Xr sysctl 3 215and 216.Xr kldsym 2 217interfaces. 218This forces the 219.Pa a.out 220argument to be ignored, and allows for symbols in 221.Xr kld 4 222modules to be used. 223.It Fl l 224Suppresses the printing of the call-graph profile. 225.It Fl L 226Suppresses the printing of the flat profile. 227.It Fl s 228A profile file 229.Pa gmon.sum 230is produced that represents 231the sum of the profile information in all the specified profile files. 232This summary profile file may be given to later 233executions of gprof (probably also with a 234.Fl s ) 235to accumulate profile data across several runs of an 236.Pa a.out 237file. 238.It Fl u 239Suppresses the printing of functions whose names are not visible to 240C programs. For the ELF object format, this means names that 241contain the 242.Ql .\& 243character. For the a.out object format, it means names that do not 244begin with a 245.Ql _ 246character. 247All relevant information about such functions belongs to the 248(non-suppressed) function with the next lowest address. 249This is useful for eliminating "functions" that are just labels 250inside other functions. 251.It Fl z 252Displays routines that have zero usage (as shown by call counts 253and accumulated time). 254This is useful with the 255.Fl c 256option for discovering which routines were never called. 257.El 258.Sh FILES 259.Bl -tag -width a.out.gmon -compact 260.It Pa a.out 261The namelist and text space. 262.It Pa a.out.gmon 263Dynamic call graph and profile. 264.It Pa gmon.sum 265Summarized dynamic call graph and profile. 266.El 267.Sh SEE ALSO 268.Xr cc 1 , 269.Xr profil 2 , 270.Xr clocks 7 271.\" .Xr monitor 3 , 272.\" .Xr prof 1 273.Rs 274.%T "An Execution Profiler for Modular Programs" 275.%A S. Graham 276.%A P. Kessler 277.%A M. McKusick 278.%J "Software - Practice and Experience" 279.%V 13 280.%P pp. 671-685 281.%D 1983 282.Re 283.Rs 284.%T "gprof: A Call Graph Execution Profiler" 285.%A S. Graham 286.%A P. Kessler 287.%A M. McKusick 288.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices" 289.%V 17 290.%N 6 291.%P pp. 120-126 292.%D June 1982 293.Re 294.Sh HISTORY 295The 296.Nm 297profiler 298appeared in 299.Bx 4.2 . 300.Sh BUGS 301The granularity of the sampling is shown, but remains 302statistical at best. 303We assume that the time for each execution of a function 304can be expressed by the total time for the function divided 305by the number of times the function is called. 306Thus the time propagated along the call graph arcs to the function's 307parents is directly proportional to the number of times that 308arc is traversed. 309.Pp 310Parents that are not themselves profiled will have the time of 311their profiled children propagated to them, but they will appear 312to be spontaneously invoked in the call graph listing, and will 313not have their time propagated further. 314Similarly, signal catchers, even though profiled, will appear 315to be spontaneous (although for more obscure reasons). 316Any profiled children of signal catchers should have their times 317propagated properly, unless the signal catcher was invoked during 318the execution of the profiling routine, in which case all is lost. 319.Pp 320The profiled program must call 321.Xr exit 3 322or return normally for the profiling information to be saved 323in the graph profile file. 324