sprof Man page

SPROF(1) Linux User Manual SPROF(1)


sprof – read and display shared object profiling data


sprof [option]… shared-object-path [profile-data-path]


The sprof command displays a profiling summary for the shared object
(shared library) 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 sprof will attempt to deduce it using the
soname of the shared object, looking for a file with the name .profile in the current directory.


The following command-line options specify the profile output to be

-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.

-p, –flat-profile
Generate a flat profile of all of the functions in the monitored
object, with counts and ticks.

-q, –graph
Generate a call graph.

If none of the above options is specified, then the default behavior is
to display a flat profile and a call graph.

The following additional command-line options are available:

-?, –help
Display a summary of command-line options and arguments and

Display a short usage message and exit.

-V, –version
Display the program version and exit.

The sprof command is a GNU extension, not present in POSIX.1.

The following example demonstrates the use of sprof. The example con‐
sists of a main program that calls two functions in a shared object.
First, the code of the main program:

$ cat prog.c

void x1(void);
void x2(void);

main(int argc, char *argv[])

The functions x1() and x2() are defined in the following source file
that is used to construct the shared object:

$ cat libdemo.c

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); } Now we construct the shared object with the real name libdemo.so.1.0.1, and the soname libdemo.so.1: $ cc -g -fPIC -shared -Wl,-soname,libdemo.so.1 \ -o libdemo.so.1.0.1 libdemo.c Then we construct symbolic links for the library soname and the library linker name: $ ln -sf libdemo.so.1.0.1 libdemo.so.1 $ ln -sf libdemo.so.1 libdemo.so Next, we compile the main program, linking it against the shared object, and then list the dynamic dependencies of the program: $ cc -g -o prog prog.c -L. -ldemo $ ldd prog 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)

In order to get profiling information for the shared object, we define
the environment variable LD_PROFILE with the soname of the library:

$ export LD_PROFILE=libdemo.so.1

We then define the environment variable 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:

$ export LD_PROFILE_OUTPUT=$(pwd)/prof_data

LD_PROFILE causes profiling output to be appended to the output file if
it already exists, so we ensure that there is no preexisting profiling


We then run the program to produce the profiling output, which is writ‐
ten to a file in the directory specified in LD_PROFILE_OUTPUT:

$ LD_LIBRARY_PATH=. ./prog
$ ls prof_data

We then use the sprof -p option to generate a flat profile with counts
and ticks:

$ sprof -p libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile
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

The sprof -q option generates a call graph:

$ sprof -q libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile

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
[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
[3] 0.0 0.00 0.00 1 x2 [3] 0.00 0.00 1000/1000 consumeCpu2 [2] ———————————————–

Above and below, the “” strings represent identifiers that are
outside of the profiled object (in this example, these are instances of

The sprof -c option generates a list of call pairs and the number of
their occurrences:

$ sprof -c libdemo.so.1 $LD_PROFILE_OUTPUT/libdemo.so.1.profile
x1 1
x1 consumeCpu1 100
x2 1
x2 consumeCpu2 1000


gprof, ldd, ld.so(8)

This page is part of release 4.04 of the Linux man-pages project. A
description of the project, information about reporting bugs, and the
latest version of this page, can be found at

Linux 2015-08-08 SPROF(1)

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