mirror of https://github.com/mkerrisk/man-pages
sprof.1: New page for the glibc sprof(1) command
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
parent
7c7a7df356
commit
2adccceb6c
|
@ -0,0 +1,301 @@
|
|||
.\" Copyright (C) 2014 Michael Kerrisk <mtk.manpages@gmail.com>
|
||||
.\"
|
||||
.\" %%%LICENSE_START(VERBATIM)
|
||||
.\" Permission is granted to make and distribute verbatim copies of this
|
||||
.\" manual provided the copyright notice and this permission notice are
|
||||
.\" preserved on all copies.
|
||||
.\"
|
||||
.\" Permission is granted to copy and distribute modified versions of this
|
||||
.\" manual under the conditions for verbatim copying, provided that the
|
||||
.\" entire resulting derived work is distributed under the terms of a
|
||||
.\" permission notice identical to this one.
|
||||
.\"
|
||||
.\" Since the Linux kernel and libraries are constantly changing, this
|
||||
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
||||
.\" responsibility for errors or omissions, or for damages resulting from
|
||||
.\" the use of the information contained herein. The author(s) may not
|
||||
.\" have taken the same level of care in the production of this manual,
|
||||
.\" which is licensed free of charge, as they might when working
|
||||
.\" professionally.
|
||||
.\"
|
||||
.\" Formatted or processed versions of this manual, if unaccompanied by
|
||||
.\" the source, must acknowledge the copyright and authors of this work.
|
||||
.\" %%%LICENSE_END
|
||||
.\"
|
||||
.TH SPROF 1 2014-06-10 "Linux" "Linux User Manual"
|
||||
.SH NAME
|
||||
sprof \- read and display shared object profiling data
|
||||
.SH SYNOPSIS
|
||||
.nf
|
||||
.BR sprof " [OPTION]... SHARED-OBJECT-PATH [PROFILE-DATA-PATH]"
|
||||
.fi
|
||||
.SH DESCRIPTION
|
||||
The
|
||||
.B sprof
|
||||
command displays a profiling summary for the
|
||||
shared object specified as its first command-line argument.
|
||||
The profiling summary is created using previously generated
|
||||
profiling data in the (optional) second command-line argument.
|
||||
If the profiling data pathname is omitted, then
|
||||
.B sprof
|
||||
will attempt to deduce it using the soname of the shared object,
|
||||
looking for a file with the name
|
||||
.IR <soname>.profile
|
||||
in the current directory.
|
||||
.SH OPTIONS
|
||||
The following command-line options specify the profile output
|
||||
to be produced:
|
||||
.TP
|
||||
.BR \-c ", " \-\-call\-pairs
|
||||
Print a list of pairs of call paths for the interfaces exported
|
||||
by the shared object,
|
||||
along with the number of times each path is used.
|
||||
.TP
|
||||
.BR \-p ", " \-\-flat\-profile
|
||||
Generate a flat profile of all of the functions in the monitored object,
|
||||
with counts and ticks.
|
||||
.TP
|
||||
.BR \-q ", " \-\-graph
|
||||
Generate a call graph.
|
||||
.PP
|
||||
If none of the above options is specified,
|
||||
then the default behavior is to display a flat profile and a call graph.
|
||||
.PP
|
||||
The following additional command-line options are available:
|
||||
.TP
|
||||
.BR \-? ", " \-\-help
|
||||
Display a summary of command-line options and arguments and exit.
|
||||
.TP
|
||||
.BR \-\-usage
|
||||
Display a short usage message and exit.
|
||||
.TP
|
||||
.BR \-V ", " \-\-version
|
||||
Display the program version and exit.
|
||||
.SH CONFORMING TO
|
||||
The
|
||||
.B sprof
|
||||
command is a GNU extension, not present in POSIX.1.
|
||||
.SH EXAMPLE
|
||||
The following example demonstrates the use of
|
||||
.BR sprof .
|
||||
The example consists of a main program that calls two functions
|
||||
in a shared library.
|
||||
First, the code of the main program:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBcat prog.c\fP
|
||||
#include <stdlib.h>
|
||||
|
||||
void x1(void);
|
||||
void x2(void);
|
||||
|
||||
int
|
||||
main(int argc, char *argv[])
|
||||
{
|
||||
x1();
|
||||
x2();
|
||||
exit(EXIT_SUCCESS);
|
||||
}
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
The functions
|
||||
.IR x1()
|
||||
and
|
||||
.IR x2()
|
||||
are defined in the following source file that is used to
|
||||
construct the shared library:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBcat libdemo.c\fP
|
||||
#include <unistd.h>
|
||||
|
||||
void
|
||||
consumeCpu1(int lim)
|
||||
{
|
||||
int j;
|
||||
|
||||
for (j = 0; j < lim; j++)
|
||||
getppid();
|
||||
}
|
||||
|
||||
void
|
||||
x1(void) {
|
||||
int j;
|
||||
|
||||
for (j = 0; j < 100; j++)
|
||||
consumeCpu1(200000);
|
||||
}
|
||||
|
||||
void
|
||||
consumeCpu2(int lim)
|
||||
{
|
||||
int j;
|
||||
|
||||
for (j = 0; j < lim; j++)
|
||||
getppid();
|
||||
}
|
||||
|
||||
void
|
||||
x2(void)
|
||||
{
|
||||
int j;
|
||||
|
||||
for (j = 0; j < 1000; j++)
|
||||
consumeCpu2(10000);
|
||||
}
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
Now we construct the shared library with the real name
|
||||
.IR libdemo.so.1.0.1 ,
|
||||
and the soname
|
||||
.IR libdemo.so.1 :
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBcc \-g \-fPIC \-shared \-Wl,\-soname,libdemo.so.1 \e\fP
|
||||
\fB\-o libdemo.so.1.0.1 libdemo.c\fP
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
Then we construct symbolic links for the library soname and
|
||||
the library linker name:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBln \-sf libdemo.so.1.0.1 libdemo.so.1\fP
|
||||
$ \fBln \-sf libdemo.so.1 libdemo.so\fP
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
Next, we compile the main program, linking it against the shared library,
|
||||
and then list the dynamic dependencies of the program:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBcc \-g \-o prog prog.c \-L. \-ldemo\fP
|
||||
$ \fBldd prog\fP
|
||||
linux\-vdso.so.1 => (0x00007fff86d66000)
|
||||
libdemo.so.1 => not found
|
||||
libc.so.6 => /lib64/libc.so.6 (0x00007fd4dc138000)
|
||||
/lib64/ld\-linux\-x86\-64.so.2 (0x00007fd4dc51f000)
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
In order to get profiling information for the shared library,
|
||||
we define the environment variable
|
||||
.BR LD_PROFILE
|
||||
with the soname of the library:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBexport LD_PROFILE=libdemo.so.1\fP
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
We then define the environment variable
|
||||
.BR LD_PROFILE_OUTPUT
|
||||
with the pathname of the directory where profile output should be written,
|
||||
and create that directory if it does not exist already:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBexport LD_PROFILE_OUTPUT=$(pwd)/prof_data\fP
|
||||
$ \fBmkdir \-p $LD_PROFILE_OUTPUT\fP
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
.B LD_PROFILE
|
||||
causes profiling output to be
|
||||
.I appended
|
||||
to the output file if it already exists,
|
||||
so we ensure that there is no preexisting profiling data:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBrm \-f $LD_PROFILE_OUTPUT/$LD_PROFILE.profile\fP
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
We then run the program to produce the profiling output,
|
||||
which is written to a file in the directory specified in
|
||||
.BR LD_PROFILE_OUTPUT :
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBLD_LIBRARY_PATH=. ./prog\fP
|
||||
$ \fBls prof_data\fP
|
||||
libdemo.so.1.profile
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
We then use the
|
||||
.BR "sprof \-p"
|
||||
option to generate a flat profile with counts and ticks:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBsprof \-p libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP
|
||||
Flat profile:
|
||||
|
||||
Each sample counts as 0.01 seconds.
|
||||
% cumulative self self total
|
||||
time seconds seconds calls us/call us/call name
|
||||
60.00 0.06 0.06 100 600.00 consumeCpu1
|
||||
40.00 0.10 0.04 1000 40.00 consumeCpu2
|
||||
0.00 0.10 0.00 1 0.00 x1
|
||||
0.00 0.10 0.00 1 0.00 x2
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
The
|
||||
.BR "sprof \-q"
|
||||
option generates a call graph:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBsprof \-q libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP
|
||||
|
||||
index % time self children called name
|
||||
|
||||
0.00 0.00 100/100 x1 [1]
|
||||
[0] 100.0 0.00 0.00 100 consumeCpu1 [0]
|
||||
\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
|
||||
0.00 0.00 1/1 <UNKNOWN>
|
||||
[1] 0.0 0.00 0.00 1 x1 [1]
|
||||
0.00 0.00 100/100 consumeCpu1 [0]
|
||||
\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
|
||||
0.00 0.00 1000/1000 x2 [3]
|
||||
[2] 0.0 0.00 0.00 1000 consumeCpu2 [2]
|
||||
\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
|
||||
0.00 0.00 1/1 <UNKNOWN>
|
||||
[3] 0.0 0.00 0.00 1 x2 [3]
|
||||
0.00 0.00 1000/1000 consumeCpu2 [2]
|
||||
\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-
|
||||
.fi
|
||||
.in
|
||||
.PP
|
||||
Above and below, the "<UNKNOWN>" strings represent identifiers that
|
||||
are outside of the profiled object (in this example, these are instances of
|
||||
.IR main() ).
|
||||
.PP
|
||||
The
|
||||
.BR "sprof \-c"
|
||||
option generates a list of call pairs and the number of their occurrences:
|
||||
|
||||
.in +4n
|
||||
.nf
|
||||
$ \fBsprof \-c libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile\fP
|
||||
<UNKNOWN> x1 1
|
||||
x1 consumeCpu1 100
|
||||
<UNKNOWN> x2 1
|
||||
x2 consumeCpu2 1000
|
||||
.fi
|
||||
.in
|
||||
.SH SEE ALSO
|
||||
.BR gprof (1),
|
||||
.BR ldd (1),
|
||||
.BR ld.so (8)
|
Loading…
Reference in New Issue