[unix-history] / usr.bin / gprof / gprof.1

.\" Copyright (c) 1983, 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)gprof.1	6.8 (Berkeley) 7/24/91
.\"
.Dd July 24, 1991
.Dt GPROF 1
.Os BSD 4.2
.Sh NAME
.Nm gprof
.Nd display call graph profile data
.Sh SYNOPSIS
.Nm gprof
.Op options
.Op Ar a.out Op Ar gmon.out ...
.Sh DESCRIPTION
.Nm Gprof
produces an execution profile of C, Pascal, or Fortran77 programs.
The effect of called routines is incorporated in the profile of each caller.
The profile data is taken from the call graph profile file
.Pf ( Pa gmon.out
default) which is created by programs
that are compiled with the
.Fl pg
option of
.Xr cc 1 ,
.Xr pc 1 ,
and
.Xr f77 1 .
The
.Fl pg
option also links in versions of the library routines
that are compiled for profiling.
.Nm Gprof
reads the given object file (the default is
.Pa a.out)
and establishes the relation between it's symbol table
and the call graph profile from
.Pa gmon.out .
If more than one profile file is specified,
the
.Nm gprof
output shows the sum of the profile information in the given profile files.
.Pp
.Nm Gprof
calculates the amount of time spent in each routine.
Next, these times are propagated along the edges of the call graph.
Cycles are discovered, and calls into a cycle are made to share the time
of the cycle.
The first listing shows the functions
sorted according to the time they represent
including the time of their call graph descendents.
Below each function entry is shown its (direct) call graph children,
and how their times are propagated to this function.
A similar display above the function shows how this function's time and the
time of its descendents is propagated to its (direct) call graph parents.
.Pp
Cycles are also shown, with an entry for the cycle as a whole and
a listing of the members of the cycle and their contributions to the
time and call counts of the cycle.
.Pp
Second, a flat profile is given,
similar to that provided by
.Xr prof  1  .
This listing gives the total execution times, the call counts,
the time in milleseconds the call spent in the routine itself, and
the time in milleseconds the call spent in the routine itself including
its descendents.
.Pp
Finally, an index of the function names is provided.
.Pp
The following options are available:
.Bl -tag -width Fl
.It Fl a
Suppresses the printing of statically declared functions.
If this option is given, all relevant information about the static function
(e.g., time samples, calls to other functions, calls from other functions)
belongs to the function loaded just before the static function in the
.Pa a.out
file.
.It Fl b
Suppresses the printing of a description of each field in the profile.
.It Fl c
The static call graph of the program is discovered by a heuristic
that examines the text space of the object file.
Static-only parents or children are shown
with call counts of 0.
.It Fl e Ar name 
Suppresses the printing of the graph profile entry for routine
.Ar name
and all its descendants
(unless they have other ancestors that aren't suppressed).
More than one
.Fl e
option may be given.
Only one
.Ar name
may be given with each
.Fl e
option.
.It Fl E Ar name 
Suppresses the printing of the graph profile entry for routine
.Ar name
(and its descendants) as
.Fl e  ,
above, and also excludes the time spent in
.Ar name
(and its descendants) from the total and percentage time computations.
(For example,
.Fl E
.Ar mcount
.Fl E
.Ar mcleanup
is the default.)
.It Fl f Ar name 
Prints the graph profile entry of only the specified routine
.Ar name
and its descendants.
More than one
.Fl f
option may be given.
Only one
.Ar name
may be given with each
.Fl f
option.
.It Fl F Ar name 
Prints the graph profile entry of only the routine
.Ar name
and its descendants (as
.Fl f ,
above) and also uses only the times of the printed routines
in total time and percentage computations.
More than one
.Fl F
option may be given.
Only one
.Ar name
may be given with each
.Fl F
option.
The
.Fl F
option
overrides
the
.Fl E
option.
.It Fl k Ar fromname Ar toname 
Will delete any arcs from routine
.Ar fromname
to routine
.Ar toname .
This can be used to break undesired cycles.
More than one
.Fl k
option may be given.
Only one pair of routine names may be given with each
.Fl k
option.
.It Fl s
A profile file
.Pa gmon.sum
is produced that represents
the sum of the profile information in all the specified profile files.
This summary profile file may be given to later
executions of gprof (probably also with a
.Fl s )
to accumulate profile data across several runs of an
.Pa a.out
file.
.It Fl z
Displays routines that have zero usage (as shown by call counts
and accumulated time).
This is useful with the
.Fl c
option for discovering which routines were never called.
.El
.Sh FILES
.Bl -tag -width gmon.sum -compact
.It Pa a.out
The namelist and text space.
.It Pa gmon.out
Dynamic call graph and profile.
.It Pa gmon.sum
Summarized dynamic call graph and profile.
.El
.Sh SEE ALSO
.Xr monitor 3 ,
.Xr profil 2 ,
.Xr cc 1 ,
.Xr prof 1
.Rs
.%T "An Execution Profiler for Modular Programs"
.%A S. Graham
.%A P. Kessler
.%A M. McKusick
.%J "Software - Practice and Experience"
.%V 13
.%P pp. 671-685
.%D 1983
.Re
.Rs
.%T "gprof: A Call Graph Execution Profiler"
.%A S. Graham
.%A P. Kessler
.%A M. McKusick
.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices"
.%V 17
.%N 6
.%P pp. 120-126
.%D June 1982
.Re
.Sh HISTORY
The
.Nm gprof
profiler
appeared in
.Bx 4.2 .
.Sh BUGS
The granularity of the sampling is shown, but remains
statistical at best.
We assume that the time for each execution of a function
can be expressed by the total time for the function divided
by the number of times the function is called.
Thus the time propagated along the call graph arcs to the function's
parents is directly proportional to the number of times that
arc is traversed.
.Pp
Parents that are not themselves profiled will have the time of
their profiled children propagated to them, but they will appear
to be spontaneously invoked in the call graph listing, and will
not have their time propagated further.
Similarly, signal catchers, even though profiled, will appear
to be spontaneous (although for more obscure reasons).
Any profiled children of signal catchers should have their times
propagated properly, unless the signal catcher was invoked during
the execution of the profiling routine, in which case all is lost.
.Pp
The profiled program must call
.Xr exit  2
or return normally for the profiling information to be saved
in the
.Pa gmon.out
file.
Commit	Line	Data
15637ed4 RG	1	.\" Copyright (c) 1983, 1990 The Regents of the University of California.
	2	.\" 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 6.8 (Berkeley) 7/24/91
	33	.\"
	34	.Dd July 24, 1991
	35	.Dt GPROF 1
	36	.Os BSD 4.2
	37	.Sh NAME
	38	.Nm gprof
	39	.Nd display call graph profile data
	40	.Sh SYNOPSIS
	41	.Nm gprof
	42	.Op options
	43	.Op Ar a.out Op Ar gmon.out ...
	44	.Sh DESCRIPTION
	45	.Nm Gprof
	46	produces an execution profile of C, Pascal, or Fortran77 programs.
	47	The effect of called routines is incorporated in the profile of each caller.
	48	The profile data is taken from the call graph profile file
	49	.Pf ( Pa gmon.out
	50	default) which is created by programs
	51	that are compiled with the
	52	.Fl pg
	53	option of
	54	.Xr cc 1 ,
	55	.Xr pc 1 ,
	56	and
	57	.Xr f77 1 .
	58	The
	59	.Fl pg
	60	option also links in versions of the library routines
	61	that are compiled for profiling.
	62	.Nm Gprof
	63	reads the given object file (the default is
	64	.Pa a.out)
65	and establishes the relation between it's symbol table
66	and the call graph profile from
67	.Pa gmon.out .
68	If more than one profile file is specified,
69	the
70	.Nm gprof
71	output shows the sum of the profile information in the given profile files.
72	.Pp
73	.Nm Gprof
74	calculates the amount of time spent in each routine.
75	Next, these times are propagated along the edges of the call graph.
76	Cycles are discovered, and calls into a cycle are made to share the time
77	of the cycle.
78	The first listing shows the functions
79	sorted according to the time they represent
80	including the time of their call graph descendents.
81	Below each function entry is shown its (direct) call graph children,
82	and how their times are propagated to this function.
83	A similar display above the function shows how this function's time and the
84	time of its descendents is propagated to its (direct) call graph parents.
85	.Pp
86	Cycles are also shown, with an entry for the cycle as a whole and
87	a listing of the members of the cycle and their contributions to the
88	time and call counts of the cycle.
89	.Pp
90	Second, a flat profile is given,
91	similar to that provided by
92	.Xr prof 1 .
93	This listing gives the total execution times, the call counts,
94	the time in milleseconds the call spent in the routine itself, and
95	the time in milleseconds the call spent in the routine itself including
96	its descendents.
97	.Pp
98	Finally, an index of the function names is provided.
99	.Pp
100	The following options are available:
101	.Bl -tag -width Fl
102	.It Fl a
103	Suppresses the printing of statically declared functions.
104	If this option is given, all relevant information about the static function
105	(e.g., time samples, calls to other functions, calls from other functions)
106	belongs to the function loaded just before the static function in the
107	.Pa a.out
108	file.
109	.It Fl b
110	Suppresses the printing of a description of each field in the profile.
111	.It Fl c
112	The static call graph of the program is discovered by a heuristic
113	that examines the text space of the object file.
114	Static-only parents or children are shown
115	with call counts of 0.
116	.It Fl e Ar name
117	Suppresses the printing of the graph profile entry for routine
118	.Ar name
119	and all its descendants
120	(unless they have other ancestors that aren't suppressed).
121	More than one
122	.Fl e
123	option may be given.
124	Only one
125	.Ar name
126	may be given with each
127	.Fl e
128	option.
129	.It Fl E Ar name
130	Suppresses the printing of the graph profile entry for routine
131	.Ar name
132	(and its descendants) as
133	.Fl e ,
134	above, and also excludes the time spent in
135	.Ar name
136	(and its descendants) from the total and percentage time computations.
137	(For example,
138	.Fl E
139	.Ar mcount
140	.Fl E
141	.Ar mcleanup
142	is the default.)
143	.It Fl f Ar name
144	Prints the graph profile entry of only the specified routine
145	.Ar name
146	and its descendants.
147	More than one
148	.Fl f
149	option may be given.
150	Only one
151	.Ar name
152	may be given with each
153	.Fl f
154	option.
155	.It Fl F Ar name
156	Prints the graph profile entry of only the routine
157	.Ar name
158	and its descendants (as
159	.Fl f ,
160	above) and also uses only the times of the printed routines
161	in total time and percentage computations.
162	More than one
163	.Fl F
164	option may be given.
165	Only one
166	.Ar name
167	may be given with each
168	.Fl F
169	option.
170	The
171	.Fl F
172	option
173	overrides
174	the
175	.Fl E
176	option.
177	.It Fl k Ar fromname Ar toname
178	Will delete any arcs from routine
179	.Ar fromname
180	to routine
181	.Ar toname .
182	This can be used to break undesired cycles.
183	More than one
184	.Fl k
185	option may be given.
186	Only one pair of routine names may be given with each
187	.Fl k
188	option.
189	.It Fl s
190	A profile file
191	.Pa gmon.sum
192	is produced that represents
193	the sum of the profile information in all the specified profile files.
194	This summary profile file may be given to later
195	executions of gprof (probably also with a
196	.Fl s )
197	to accumulate profile data across several runs of an
198	.Pa a.out
199	file.
200	.It Fl z
201	Displays routines that have zero usage (as shown by call counts
202	and accumulated time).
203	This is useful with the
204	.Fl c
205	option for discovering which routines were never called.
206	.El
207	.Sh FILES
208	.Bl -tag -width gmon.sum -compact
209	.It Pa a.out
210	The namelist and text space.
211	.It Pa gmon.out
212	Dynamic call graph and profile.
213	.It Pa gmon.sum
214	Summarized dynamic call graph and profile.
215	.El
216	.Sh SEE ALSO
217	.Xr monitor 3 ,
218	.Xr profil 2 ,
219	.Xr cc 1 ,
220	.Xr prof 1
221	.Rs
222	.%T "An Execution Profiler for Modular Programs"
223	.%A S. Graham
224	.%A P. Kessler
225	.%A M. McKusick
226	.%J "Software - Practice and Experience"
227	.%V 13
228	.%P pp. 671-685
229	.%D 1983
230	.Re
231	.Rs
232	.%T "gprof: A Call Graph Execution Profiler"
233	.%A S. Graham
234	.%A P. Kessler
235	.%A M. McKusick
236	.%J "Proceedings of the SIGPLAN '82 Symposium on Compiler Construction, SIGPLAN Notices"
237	.%V 17
238	.%N 6
239	.%P pp. 120-126
240	.%D June 1982
241	.Re
242	.Sh HISTORY
243	The
244	.Nm gprof
245	profiler
246	appeared in
247	.Bx 4.2 .
248	.Sh BUGS
249	The granularity of the sampling is shown, but remains
250	statistical at best.
251	We assume that the time for each execution of a function
252	can be expressed by the total time for the function divided
253	by the number of times the function is called.
254	Thus the time propagated along the call graph arcs to the function's
255	parents is directly proportional to the number of times that
256	arc is traversed.
257	.Pp
258	Parents that are not themselves profiled will have the time of
259	their profiled children propagated to them, but they will appear
260	to be spontaneously invoked in the call graph listing, and will
261	not have their time propagated further.
262	Similarly, signal catchers, even though profiled, will appear
263	to be spontaneous (although for more obscure reasons).
264	Any profiled children of signal catchers should have their times
265	propagated properly, unless the signal catcher was invoked during
266	the execution of the profiling routine, in which case all is lost.
267	.Pp
268	The profiled program must call
269	.Xr exit 2
270	or return normally for the profiling information to be saved
271	in the
272	.Pa gmon.out
273	file.