Intel® VTune™ Amplifier XE and Intel® VTune™ Amplifier for Systems Help
Intel® VTune™ Amplifier uses kernel drivers to enable the hardware event-based sampling and Energy analysis (the latter is available with the VTune Amplifier for Systems only). VTune Amplifier installer automatically uses the Sampling Driver Kit and the Power Driver Kit to build drivers for your kernel with the default installation options. If the drivers were not built and set up during installation (for example, lack of privileges, missing kernel development RPM, and so on), VTune Amplifier provides an error message and, on Linux* and Android* systems, enables driverless sampling data collection based on the Linux Perf* tool functionality, which has a limited scope of analysis options. But you may still enable a full-scale sampling data collection or Energy analysis by:
You may need kernel header sources and other additional software to build and load the kernel drivers on Linux. For details, see the README.txt files in the sepdk/src and powerdk/src directories.
A Linux kernel update can lead to incompatibility with VTune Amplifier drivers set up on the system for event-based sampling (EBS) analysis and power analysis. If the system has installed VTune Amplifier boot scripts to load the drivers into the kernel each time the system is rebooted, the drivers will be automatically re-built by the boot scripts at system boot time. Kernel development sources required for driver rebuild should correspond to the Linux kernel update.
If you loaded the drivers but do not use them and no collection is happening, there is no execution time overhead of having the drivers loaded. The memory overhead is also minimal. You can let the drivers be loaded at boot time (for example, via the install-boot-script, which is used by default) and not worry about it. Unless data is being collected by the VTune Amplifier, there will be no latency impact on system performance.
During product installation on Linux OS, you may control the drivers installation options via the Change advanced options menu item. VTune Amplifier provides the following options:
Use This Option |
To Do This |
|---|---|
Sampling driver install type [build driver (default) / driver kit files only ] Power driver install type [build driver (default) / driver kit files only ] |
Choose the driver installation option. By default, VTune Amplifier uses the Sampling/Power Driver Kit to build the driver for your kernel. You may change the option to driver kit files only if you want to build the driver manually after installation. |
Driver access group [ vtune (default) ] |
Set the driver access group ownership to determine which set of users can perform the collection on the system. By default, the group is vtune. Access to this group is not restricted. To restrict access, see the Driver permissions option below. You may set your own group during installation in the Advanced options or change it manually after installation by executing: ./boot-script -–group <your_group> from the <install_dir>/sepdk/src or <install_dir>/powerdk/srcdirectories. |
Driver permissions [ 660 (default) ] |
Change permissions for the driver. The default permissions allow any user to access the driver. Using this access the user can profile the system, an application, or attach to a process. |
Load driver [ yes (default) ] |
Load the driver into the kernel. |
Install boot script [ yes (default) ] |
Use a boot script that loads the driver into the kernel each time the system is rebooted. The boot script can be disabled later by executing: ./boot-script --uninstall from the <install_dir>/sepdk/src or <install_dir>/powerdk/src directories. |
Enable per-user collection mode [no (default) / yes] |
Install the hardware event-based collector driver with the per-user filtering on. When the filtering is on, the collector gathers data only for the processes spawned by the user who started the collection. When it is off (default), samples from all processes on the system are collected. Consider using the filtering to isolate the collection from other users on a cluster for security reasons. The administrator/root can change the filtering mode by rebuilding/restarting the driver at any time. A regular user cannot change the mode after the product is installed. NoteFor MPI application analysis on a Linux* cluster, you may enable the Per-user Hardware Event-based Sampling mode when installing the Intel Cluster Studio XE. This option ensures that during the collection the VTune Amplifier collects data only for the current user. Once enabled by the administrator during the installation, this mode cannot be turned off by a regular user, which is intentional to preclude individual users from observing the performance data over the whole node including activities of other users. After installation, you can use the respective -vars.sh files to set up the appropriate environment (PATH, MANPATH) in the current terminal session. |
Driver build options … |
Specify the location of the kernel header files on this system, the path and name of the C compiler to use for building the driver, the path and name of the make command to use for building the driver. |