from small one page howto to huge articles all in one place
 

search text in:





Poll
Which screen resolution do you use?










poll results

Last additions:
using iotop to find disk usage hogs

using iotop to find disk usage hogs

words:

887

views:

109359

userrating:

average rating: 1.7 (85 votes) (1=very good 6=terrible)


May 25th. 2007:
Words

486

Views

223374

why adblockers are bad


Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

words:

161

views:

103647

userrating:

average rating: 1.3 (28 votes) (1=very good 6=terrible)


April, 26th. 2006:

Druckversion
You are here: manpages





SPROF

Section: Linux User Manual (1)
Updated: 2017-09-15
Index Return to Main Contents
 

NAME

sprof - read and display shared object profiling data  

SYNOPSIS

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

DESCRIPTION

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 <soname>.profile in the current directory.  

OPTIONS

The following command-line options specify the profile output to be produced:
-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 exit.
--usage
Display a short usage message and exit.
-V, --version
Display the program version and exit.
 

CONFORMING TO

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

EXAMPLE

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

$ cat prog.c #include <stdlib.h>

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

int main(int argc, char *argv[]) {
    x1();
    x2();
    exit(EXIT_SUCCESS); }

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

$ cat libdemo.c #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);
}

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 $ mkdir -p $LD_PROFILE_OUTPUT

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 data:

$ rm -f $LD_PROFILE_OUTPUT/$LD_PROFILE.profile

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

$ LD_LIBRARY_PATH=. ./prog $ ls prof_data libdemo.so.1.profile

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           <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] -----------------------------------------------

Above and below, the "<UNKNOWN>" strings represent identifiers that are outside of the profiled object (in this example, these are instances of main()).

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 <UNKNOWN> x1 1 x1 consumeCpu1 100 <UNKNOWN> x2 1 x2 consumeCpu2 1000  

SEE ALSO

gprof(1), ldd(1), ld.so(8)  

COLOPHON

This page is part of release 4.13 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 https://www.kernel.org/doc/man-pages/.


 

Index

NAME
SYNOPSIS
DESCRIPTION
OPTIONS
CONFORMING TO
EXAMPLE
SEE ALSO
COLOPHON


Please read "Why adblockers are bad".



Other free services
toURL.org
Shorten long
URLs to short
links like
http://tourl.org/2
tourl.org
.
Reverse DNS lookup
Find out which hostname(s)
resolve to a
given IP or other hostnames for the server
www.reversednslookup.org
rdf newsfeed | rss newsfeed | Atom newsfeed
- Powered by LeopardCMS - Running on Gentoo -
Copyright 2004-2017 Sascha Nitsch Unternehmensberatung UG(haftungsbeschränkt)
Valid XHTML1.1 : Valid CSS : buttonmaker
- Level Triple-A Conformance to Web Content Accessibility Guidelines 1.0 -
- Copyright and legal notices -
Time to create this page: 3.2 ms