Intel® VTune™ Profiler

User Guide

ID 766319
Date 3/22/2024
Public

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Document Table of Contents

Configure Your Build System

NOTE:

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

NOTE:

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:

NOTE:

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.

NOTE:

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 theINTEL_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