Intel® VTune™ Profiler User Guide

User Guide

Contents

Configure Your Build System

ITT API usage is supported on Windows*, Linux*, FreeBSD*, and Android* systems. It is not supported for QNX* systems.
Before instrumenting your application, you need to configure your build system to be able to reach the API headers and libraries.
For Windows* and Linux* systems:
  • Add
    <install_dir>
    /sdk/include
     to your INCLUDE path for C/C++ applications or
    <install_dir>
    /sdk/[lib32 or lib64]
     to your INCLUDE path for Fortran applications
  • Add
    <install_dir>
    /sdk/lib32
     to your 32-bit LIBRARIES path
  • Add
    <install_dir>
    /sdk/lib64
     to your 64-bit LIBRARIES path
On Linux* systems, you have to link the
dl
 and
pthread
 libraries to enable ITT API functionality. Not linking these libraries will not prevent your application from running, but no ITT API data will be collected.
For FreeBSD* systems:
Header and library files are available from the
vtune_profiler_target_x86_64.tgz
 FreeBSD target package. See Set Up FreeBSD* System for more information.
  • Add
    <target-package>
    /sdk/include
     to your INCLUDE path for C/C++ applications or
    <install_dir>
    /sdk/[lib32 or lib64]
     to your INCLUDE path for Fortran applications
  • Add
    <target-package>
    /sdk/lib64
     to your 64-bit LIBRARIES path
For the Android* system, add the following libraries to your LIBRARIES path depending on your device architecture:
  • Add
    <install_dir>
    /target/android_v5_x86_64/lib-x86_64
     for the Intel® 64 architecture
  • Add
    <install_dir>
    /target/android_v5/lib-x86
     for the IA-32 architecture
  • Add
    <install_dir>
    /target/android_arm/lib-arm
     for the ARM* architecture
<install_dir>
 is the
Intel®
VTune™
Profiler
 installation directory. The default installation path for the VTune
Profiler
 varies with the product shipment.
The ITT API headers, static libraries, and Fortran modules previously located at
<install_dir>/include
 and
<install_dir>/lib32 [64]
 folders were moved to the
<install_dir>/sdk
 folder starting the
VTune
Profiler
 2021.1-beta08 release. Copies of these files are retained at their old locations for backwards compatibility and these copies should not be used for new projects.

Include the ITT API Header or Module in Your Application

For C/C++ Applications
Add the following
#include
 statements to every source file that you want to instrument: 
#include <ittnotify.h>
The
ittnotify.h
 header contains definitions of ITT API routines and important macros which provide the correct logic of API invocation from a user application.
The ITT API is designed to incur almost zero overhead when tracing is disabled. But if you need fully zero overhead, you can compile out all ITT API calls from your application by defining the
INTEL_NO_ITTNOTIFY_API
 macro in your project at compile time, either on the compiler command line, or in your source file, prior to including the
ittnotify.h
 file.
For Fortran Applications
Add the
ITTNOTIFY
 module to your source files with the following source line: 
USE ITTNOTIFY

Insert ITT Notifications in Your Application

Insert
__itt_*
 (C/C++) or
ITT_*
 (Fortran) notifications in your source code.
C/C++ example: 
__itt_pause();
Fortran example: 
CALL ITT_PAUSE()
For more information, see Instrumenting Your Application.

Link the libittnotify.a (Linux*, Android*, FreeBSD*) or libittnotify.lib (Windows*) Static Library to Your Application

You need to link the static library,
libittnotify.a
 (Linux*, FreeBSD*, Android*) or
libittnotify.lib
 (Windows*), to your application. If tracing is enabled, this static library loads the ITT API implementation and forwards ITT API instrumentation data to
VTune
Profiler
. If tracing is disabled, the static library ignores ITT API calls, causing nearly zero instrumentation overhead.
After you instrument your application by adding ITT API calls to your code and link the
libittnotify.a
 (Linux*, FreeBSD*, Android*) or
libittnotify.lib
 (Windows*) static library, your application will check the
INTEL_LIBITTNOTIFY32
 or the
INTEL_LIBITTNOTIFY64
 environment variable depending on your application's architecture. If that variable is set, it will load the libraries defined in the variable.
Make sure to set these environment variables for the
ittnotify_collector
 to enable data collection:
On Windows*:
INTEL_LIBITTNOTIFY32=<
install-dir
>\bin32\runtime\ittnotify_collector.dll
INTEL_LIBITTNOTIFY64=<
install-dir
>\bin64\runtime\ittnotify_collector.dll
On Linux*:
INTEL_LIBITTNOTIFY32=<
install-dir
>/lib32/runtime/libittnotify_collector.so
INTEL_LIBITTNOTIFY64=<
install-dir
>/lib64/runtime/libittnotify_collector.so
On FreeBSD*:
INTEL_LIBITTNOTIFY64=<
target-package
>/lib64/runtime/libittnotify_collector.so

Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.