| 1 | .\" Copyright (c) 1983, 1990 The Regents of the University of California. |
| 2 | .\" All rights reserved. |
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| 18 | .\" @(#)gprof.1 6.6 (Berkeley) 7/24/90 |
| 19 | .\" |
| 20 | .TH GPROF 1 "January 29, 1993" |
| 21 | .SH NAME |
| 22 | gprof \- display call graph profile data |
| 23 | .SH SYNOPSIS |
| 24 | .B gprof [ \-abcsz ] [ \-e|\-E |
| 25 | .I name |
| 26 | .B ] [ \-f|\-F |
| 27 | .I name |
| 28 | .B ] |
| 29 | .B [ \-k |
| 30 | .I fromname toname |
| 31 | .B ] [ |
| 32 | .I objfile |
| 33 | .B [ |
| 34 | .I gmon.out |
| 35 | .B ] |
| 36 | .B ] |
| 37 | .SH DESCRIPTION |
| 38 | .B gprof |
| 39 | produces an execution profile of C, Pascal, or Fortran77 programs. |
| 40 | The effect of called routines is incorporated in the profile of each caller. |
| 41 | The profile data is taken from the call graph profile file |
| 42 | \&(`gmon.out' default) which is created by programs |
| 43 | that are compiled with the |
| 44 | .B \-pg |
| 45 | option of |
| 46 | .BR cc ( 1 ) , |
| 47 | .BR pc ( 1 ) , |
| 48 | and |
| 49 | .BR f77 ( 1 ) . |
| 50 | The |
| 51 | .B \-pg |
| 52 | option also links in versions of the library routines |
| 53 | that are compiled for profiling. |
| 54 | .B Gprof |
| 55 | reads the given object file (the default is `a.out') |
| 56 | and establishes the relation between its symbol table |
| 57 | and the call graph profile from `gmon.out'. |
| 58 | If more than one profile file is specified, |
| 59 | the |
| 60 | .B gprof |
| 61 | output shows the sum of the profile information in the given profile files. |
| 62 | .PP |
| 63 | .B Gprof |
| 64 | calculates the amount of time spent in each routine. |
| 65 | Next, these times are propagated along the edges of the call graph. |
| 66 | Cycles are discovered, and calls into a cycle are made to share the time |
| 67 | of the cycle. |
| 68 | The first listing shows the functions |
| 69 | sorted according to the time they represent |
| 70 | including the time of their call graph descendants. |
| 71 | Below each function entry is shown its (direct) call graph children, |
| 72 | and how their times are propagated to this function. |
| 73 | A similar display above the function shows how this function's time and the |
| 74 | time of its descendants is propagated to its (direct) call graph parents. |
| 75 | .PP |
| 76 | Cycles are also shown, with an entry for the cycle as a whole and |
| 77 | a listing of the members of the cycle and their contributions to the |
| 78 | time and call counts of the cycle. |
| 79 | .PP |
| 80 | Second, a flat profile is given, |
| 81 | similar to that provided by |
| 82 | .BR prof ( 1 ) . |
| 83 | This listing gives the total execution times, the call counts, |
| 84 | the time in milliseconds the call spent in the routine itself, and |
| 85 | the time in milliseconds the call spent in the routine itself including |
| 86 | its descendants. |
| 87 | .PP |
| 88 | Finally, an index of the function names is provided. |
| 89 | .SH OPTIONS |
| 90 | The following options are available: |
| 91 | .TP |
| 92 | .B \-a |
| 93 | suppresses the printing of statically declared functions. |
| 94 | If this option is given, all relevant information about the static function |
| 95 | (e.g., time samples, calls to other functions, calls from other functions) |
| 96 | belongs to the function loaded just before the static function in the |
| 97 | \&`objfile' file. |
| 98 | .TP |
| 99 | .B \-b |
| 100 | suppresses the printing of a description of each field in the profile. |
| 101 | .TP |
| 102 | .B \-c |
| 103 | the static call graph of the program is discovered by a heuristic |
| 104 | that examines the text space of the object file. |
| 105 | Static-only parents or children are shown |
| 106 | with call counts of 0. |
| 107 | .TP |
| 108 | .BI "\-e " name |
| 109 | suppresses the printing of the graph profile entry for routine |
| 110 | .I name |
| 111 | and all its descendants |
| 112 | (unless they have other ancestors that aren't suppressed). |
| 113 | More than one |
| 114 | .B \-e |
| 115 | option may be given. |
| 116 | Only one |
| 117 | .I name |
| 118 | may be given with each |
| 119 | .B \-e |
| 120 | option. |
| 121 | .TP |
| 122 | .BI "\-E " name |
| 123 | suppresses the printing of the graph profile entry for routine |
| 124 | .I name |
| 125 | (and its descendants) as |
| 126 | .B \-e , |
| 127 | above, and also excludes the time spent in |
| 128 | .I name |
| 129 | (and its descendants) from the total and percentage time computations. |
| 130 | (For example, |
| 131 | .BI "\-E " mcount |
| 132 | .BI "\-E " mcleanup |
| 133 | is the default.) |
| 134 | .TP |
| 135 | .BI "\-f " name |
| 136 | prints the graph profile entry of only the specified routine |
| 137 | .I name |
| 138 | and its descendants. |
| 139 | More than one |
| 140 | .B \-f |
| 141 | option may be given. |
| 142 | Only one |
| 143 | .I name |
| 144 | may be given with each |
| 145 | .B \-f |
| 146 | option. |
| 147 | .TP |
| 148 | .BI "\-F " name |
| 149 | prints the graph profile entry of only the routine |
| 150 | .I name |
| 151 | and its descendants (as |
| 152 | .B \-f , |
| 153 | above) and also uses only the times of the printed routines |
| 154 | in total time and percentage computations. |
| 155 | More than one |
| 156 | .B \-F |
| 157 | option may be given. |
| 158 | Only one |
| 159 | .I name |
| 160 | may be given with each |
| 161 | .B \-F |
| 162 | option. |
| 163 | The |
| 164 | .B \-F |
| 165 | option |
| 166 | overrides |
| 167 | the |
| 168 | .B \-E |
| 169 | option. |
| 170 | .TP |
| 171 | .BI "\-k " "fromname toname" |
| 172 | will delete any arcs from routine |
| 173 | .I fromname |
| 174 | to routine |
| 175 | .IR toname . |
| 176 | This can be used to break undesired cycles. |
| 177 | More than one |
| 178 | .B \-k |
| 179 | option may be given. |
| 180 | Only one pair of routine names may be given with each |
| 181 | .B \-k |
| 182 | option. |
| 183 | .TP |
| 184 | .B \-s |
| 185 | a profile file `gmon.sum' is produced that represents |
| 186 | the sum of the profile information in all the specified profile files. |
| 187 | This summary profile file may be given to later |
| 188 | executions of gprof (probably also with a |
| 189 | .BR \-s ) |
| 190 | to accumulate profile data across several runs of an `objfile' file. |
| 191 | .TP |
| 192 | .B -v |
| 193 | prints the version number for gprof, and then exits. |
| 194 | .TP |
| 195 | .B -z |
| 196 | displays routines that have zero usage (as shown by call counts |
| 197 | and accumulated time). |
| 198 | This is useful with the |
| 199 | .B \-c |
| 200 | option for discovering which routines were never called. |
| 201 | .PP |
| 202 | .SH FILES |
| 203 | .ta \w'gmon.sum 'u |
| 204 | a.out the namelist and text space. |
| 205 | .br |
| 206 | gmon.out dynamic call graph and profile. |
| 207 | .br |
| 208 | gmon.sum summarized dynamic call graph and profile. |
| 209 | .SH SEE ALSO |
| 210 | .BR monitor ( 3 ) , |
| 211 | .BR profil ( 2 ) , |
| 212 | .BR cc ( 1 ) , |
| 213 | .BR prof ( 1 ) |
| 214 | .sp |
| 215 | ``An Execution Profiler for Modular Programs'', |
| 216 | by S. Graham, P. Kessler, M. McKusick; |
| 217 | .I |
| 218 | Software \- Practice and Experience, |
| 219 | Vol. 13, pp. 671-685, 1983. |
| 220 | .sp |
| 221 | ``gprof: A Call Graph Execution Profiler'', |
| 222 | by S. Graham, P. Kessler, M. McKusick; |
| 223 | .I |
| 224 | Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, |
| 225 | SIGPLAN Notices, Vol. 17, No 6, pp. 120-126, June 1982. |
| 226 | .SH HISTORY |
| 227 | .B Gprof |
| 228 | appeared in 4.2 BSD. |
| 229 | .SH BUGS |
| 230 | The granularity of the sampling is shown, but remains |
| 231 | statistical at best. |
| 232 | We assume that the time for each execution of a function |
| 233 | can be expressed by the total time for the function divided |
| 234 | by the number of times the function is called. |
| 235 | Thus the time propagated along the call graph arcs to the function's |
| 236 | parents is directly proportional to the number of times that |
| 237 | arc is traversed. |
| 238 | .PP |
| 239 | Parents that are not themselves profiled will have the time of |
| 240 | their profiled children propagated to them, but they will appear |
| 241 | to be spontaneously invoked in the call graph listing, and will |
| 242 | not have their time propagated further. |
| 243 | Similarly, signal catchers, even though profiled, will appear |
| 244 | to be spontaneous (although for more obscure reasons). |
| 245 | Any profiled children of signal catchers should have their times |
| 246 | propagated properly, unless the signal catcher was invoked during |
| 247 | the execution of the profiling routine, in which case all is lost. |
| 248 | .PP |
| 249 | The profiled program must call |
| 250 | .BR exit ( 2 ) |
| 251 | or return normally for the profiling information to be saved |
| 252 | in the `gmon.out' file. |