1 .\" Copyright (c) 1983, 1990 The Regents of the University of California.
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14 .\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
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18 .\" @(#)gprof.1 6.6 (Berkeley) 7/24/90
20 .TH GPROF 1 "July 24, 1990"
22 gprof \- display call graph profile data
30 produces an execution profile of C, Pascal, or Fortran77 programs.
31 The effect of called routines is incorporated in the profile of each caller.
32 The profile data is taken from the call graph profile file
33 \&(`gmon.out' default) which is created by programs
34 that are compiled with the
43 option also links in versions of the library routines
44 that are compiled for profiling.
46 reads the given object file (the default is `a.out')
47 and establishes the relation between its symbol table
48 and the call graph profile from `gmon.out'.
49 If more than one profile file is specified,
52 output shows the sum of the profile information in the given profile files.
55 calculates the amount of time spent in each routine.
56 Next, these times are propagated along the edges of the call graph.
57 Cycles are discovered, and calls into a cycle are made to share the time
59 The first listing shows the functions
60 sorted according to the time they represent
61 including the time of their call graph descendents.
62 Below each function entry is shown its (direct) call graph children,
63 and how their times are propagated to this function.
64 A similar display above the function shows how this function's time and the
65 time of its descendents is propagated to its (direct) call graph parents.
67 Cycles are also shown, with an entry for the cycle as a whole and
68 a listing of the members of the cycle and their contributions to the
69 time and call counts of the cycle.
71 Second, a flat profile is given,
72 similar to that provided by
74 This listing gives the total execution times, the call counts,
75 the time in milleseconds the call spent in the routine itself, and
76 the time in milleseconds the call spent in the routine itself including
79 Finally, an index of the function names is provided.
81 The following options are available:
84 suppresses the printing of statically declared functions.
85 If this option is given, all relevant information about the static function
86 (e.g., time samples, calls to other functions, calls from other functions)
87 belongs to the function loaded just before the static function in the
91 suppresses the printing of a description of each field in the profile.
94 the static call graph of the program is discovered by a heuristic
95 that examines the text space of the object file.
96 Static-only parents or children are shown
97 with call counts of 0.
100 suppresses the printing of the graph profile entry for routine
102 and all its descendants
103 (unless they have other ancestors that aren't suppressed).
109 may be given with each
114 suppresses the printing of the graph profile entry for routine
116 (and its descendants) as
118 above, and also excludes the time spent in
120 (and its descendants) from the total and percentage time computations.
127 prints the graph profile entry of only the specified routine
135 may be given with each
140 prints the graph profile entry of only the routine
142 and its descendants (as
144 above) and also uses only the times of the printed routines
145 in total time and percentage computations.
151 may be given with each
162 .BI "\-k " "fromname toname"
163 will delete any arcs from routine
167 This can be used to break undesired cycles.
171 Only one pair of routine names may be given with each
176 a profile file `gmon.sum' is produced that represents
177 the sum of the profile information in all the specified profile files.
178 This summary profile file may be given to later
179 executions of gprof (probably also with a
181 to accumulate profile data across several runs of an `a.out' file.
184 displays routines that have zero usage (as shown by call counts
185 and accumulated time).
186 This is useful with the
188 option for discovering which routines were never called.
192 a.out the namelist and text space.
194 gmon.out dynamic call graph and profile.
196 gmon.sum summarized dynamic call graph and profile.
203 ``An Execution Profiler for Modular Programs'',
204 by S. Graham, P. Kessler, M. McKusick;
206 Software \- Practice and Experience,
207 Vol. 13, pp. 671-685, 1983.
209 ``gprof: A Call Graph Execution Profiler'',
210 by S. Graham, P. Kessler, M. McKusick;
212 Proceedings of the SIGPLAN '82 Symposium on Compiler Construction,
213 SIGPLAN Notices, Vol. 17, No 6, pp. 120-126, June 1982.
218 The granularity of the sampling is shown, but remains
220 We assume that the time for each execution of a function
221 can be expressed by the total time for the function divided
222 by the number of times the function is called.
223 Thus the time propagated along the call graph arcs to the function's
224 parents is directly proportional to the number of times that
227 Parents that are not themselves profiled will have the time of
228 their profiled children propagated to them, but they will appear
229 to be spontaneously invoked in the call graph listing, and will
230 not have their time propagated further.
231 Similarly, signal catchers, even though profiled, will appear
232 to be spontaneous (although for more obscure reasons).
233 Any profiled children of signal catchers should have their times
234 propagated properly, unless the signal catcher was invoked during
235 the execution of the profiling routine, in which case all is lost.
237 The profiled program must call
239 or return normally for the profiling information to be saved
240 in the `gmon.out' file.