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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 October 7, 2005 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 abKlLsuz 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 that the call spent in the routine itself, and 115the time that the call spent in the routine itself including 116its descendants. 117The units for the per-call times are normally milliseconds, 118but they are nanoseconds if the profiling clock frequency 119is 10 million or larger, 120and if a function appears to be never called then its total self time 121is printed as a percentage in the self time per call column. 122The very high profiling clock frequencies needed to get sufficient 123accuracy in the per-call times for short-lived programs are only 124implemented for 125.Dq high resolution 126(non-statistical) kernel profiling. 127.Pp 128Finally, an index of the function names is provided. 129.Pp 130The following options are available: 131.Bl -tag -width indent 132.It Fl a 133Suppress the printing of statically declared functions. 134If this option is given, all relevant information about the static function 135(e.g., time samples, calls to other functions, calls from other functions) 136belongs to the function loaded just before the static function in the 137.Pa a.out 138file. 139.It Fl b 140Suppress the printing of a description of each field in the profile. 141.It Fl C Ar count 142Find a minimal set of arcs that can be broken to eliminate all cycles with 143.Ar count 144or more members. 145Caution: the algorithm used to break cycles is exponential, 146so using this option may cause 147.Nm 148to run for a very long time. 149.It Fl e Ar name 150Suppress the printing of the graph profile entry for routine 151.Ar name 152and all its descendants 153(unless they have other ancestors that are not suppressed). 154More than one 155.Fl e 156option may be given. 157Only one 158.Ar name 159may be given with each 160.Fl e 161option. 162.It Fl E Ar name 163Suppress the printing of the graph profile entry for routine 164.Ar name 165(and its descendants) as 166.Fl e , 167above, and also excludes the time spent in 168.Ar name 169(and its descendants) from the total and percentage time computations. 170(For example, 171.Fl E 172.Ar mcount 173.Fl E 174.Ar mcleanup 175is the default.) 176.It Fl f Ar name 177Print the graph profile entry of only the specified routine 178.Ar name 179and its descendants. 180More than one 181.Fl f 182option may be given. 183Only one 184.Ar name 185may be given with each 186.Fl f 187option. 188.It Fl F Ar name 189Print the graph profile entry of only the routine 190.Ar name 191and its descendants (as 192.Fl f , 193above) and also uses only the times of the printed routines 194in total time and percentage computations. 195More than one 196.Fl F 197option may be given. 198Only one 199.Ar name 200may be given with each 201.Fl F 202option. 203The 204.Fl F 205option 206overrides 207the 208.Fl E 209option. 210.It Fl k Ar fromname Ar toname 211Will delete any arcs from routine 212.Ar fromname 213to routine 214.Ar toname . 215This can be used to break undesired cycles. 216More than one 217.Fl k 218option may be given. 219Only one pair of routine names may be given with each 220.Fl k 221option. 222.It Fl K 223Gather information about symbols from the currently-running kernel using the 224.Xr sysctl 3 225and 226.Xr kldsym 2 227interfaces. 228This forces the 229.Pa a.out 230argument to be ignored, and allows for symbols in 231.Xr kld 4 232modules to be used. 233.It Fl l 234Suppress the printing of the call-graph profile. 235.It Fl L 236Suppress the printing of the flat profile. 237.It Fl s 238A profile file 239.Pa gmon.sum 240is produced that represents 241the sum of the profile information in all the specified profile files. 242This summary profile file may be given to later 243executions of gprof (probably also with a 244.Fl s ) 245to accumulate profile data across several runs of an 246.Pa a.out 247file. 248.It Fl u 249Suppress the printing of functions whose names are not visible to 250C programs. 251For the ELF object format, this means names that 252contain the 253.Ql .\& 254character. 255For the a.out object format, it means names that do not 256begin with a 257.Ql _ 258character. 259All relevant information about such functions belongs to the 260(non-suppressed) function with the next lowest address. 261This is useful for eliminating "functions" that are just labels 262inside other functions. 263.It Fl z 264Display routines that have zero usage (as shown by call counts 265and accumulated time). 266This is useful with the 267.Fl c 268option for discovering which routines were never called. 269.El 270.Sh FILES 271.Bl -tag -width a.out.gmon -compact 272.It Pa a.out 273The namelist and text space. 274.It Pa a.out.gmon 275Dynamic call graph and profile. 276.It Pa gmon.sum 277Summarized dynamic call graph and profile. 278.El 279.Sh SEE ALSO 280.Xr cc 1 , 281.Xr profil 2 , 282.Xr clocks 7 283.\" .Xr monitor 3 , 284.\" .Xr prof 1 285.Rs 286.%T "An Execution Profiler for Modular Programs" 287.%A S. Graham 288.%A P. Kessler 289.%A M. McKusick 290.%J "Software - Practice and Experience" 291.%V 13 292.%P pp. 671-685 293.%D 1983 294.Re 295.Rs 296.%T "gprof: A Call Graph Execution Profiler" 297.%A S. Graham 298.%A P. Kessler 299.%A M. McKusick 300.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices" 301.%V 17 302.%N 6 303.%P pp. 120-126 304.%D June 1982 305.Re 306.Sh HISTORY 307The 308.Nm 309profiler 310appeared in 311.Bx 4.2 . 312.Sh BUGS 313The granularity of the sampling is shown, but remains 314statistical at best. 315We assume that the time for each execution of a function 316can be expressed by the total time for the function divided 317by the number of times the function is called. 318Thus the time propagated along the call graph arcs to the function's 319parents is directly proportional to the number of times that 320arc is traversed. 321.Pp 322Parents that are not themselves profiled will have the time of 323their profiled children propagated to them, but they will appear 324to be spontaneously invoked in the call graph listing, and will 325not have their time propagated further. 326Similarly, signal catchers, even though profiled, will appear 327to be spontaneous (although for more obscure reasons). 328Any profiled children of signal catchers should have their times 329propagated properly, unless the signal catcher was invoked during 330the execution of the profiling routine, in which case all is lost. 331.Pp 332The profiled program must call 333.Xr exit 3 334or return normally for the profiling information to be saved 335in the graph profile file. 336