VTune™ Analyzer: Other32 Module Solutions

by Corey Alsamriae

The Time Based sampling (TBS) feature of the Intel® VTune™ Performance Analyzer allows you to monitor all active software on your system, including the operating system, device drivers, and application software, collecting information at regular time intervals. The VTune Performance Analyzer then analyzes this data to provide a detailed view of the system's activity.

When using the VTune Performance Analyzer's TBS feature, you may encounter instances in which sampled modules are identified as Other32 (or Other16, OtherV86, Other64). This happens when the VTune analyzer cannot locate the sample collected in any of the currently loaded modules. For example, 32-Bit DOS* Extenders do not register anything, and all of their activity is lumped into the category Other32.

Another example is the BIOS, which was never loaded by Windows because it is there at boot time. To identify what is running on the system, the VTune analyzer hooks an operating system service for notification of all loaded applications, modules, drivers, services, etc. When a sample is collected that is not within any of the loaded modules, the VTune analyzer categorizes it as Other32. The VTune analyzer places samples from unregistered code in Other32 because it only tracks modules that are loaded by the operating system and which follow proper Microsoft Windows* registration protocols.

There are four cases in which the VTune analyzer categorizes samples as Other32. These cases and solutions are as follows:

Case 1:
The operating system has never loaded the code, such as power saving code (in the BIOS) or self-generated code.

Solution:
You can get an idea if the samples are in the BIOS by looking at the log file generated in the VTune analyzer project directory. This file is a plain text file.

Case 2:
The operating system failed to notify VTune analyzer due to a minor issue in the Microsoft Windows NT* kernel.

Solution:
This can be fixed most of the time by selecting in the Configure/Options/Global dialogue the option to "Use Module Tracking to dynamically track module loads".

Case 3:
The VTune analyzer is sometimes unable to read the process description for some system services due to security on Microsoft Windows NT.

Solution:
On Microsoft Windows NT 4.0, SP3 and older, make sure in the configuration options, global settings to check "Use Module Tracking to dynamically track module loads".

Case 4:
When running time-based sampling on Microsoft* Windows NT 4.0 you may find that all your DLL samples appear under Other32 instead of under your DLLs.

Solution:
Add a Start Delay (Page: 2 the number of seconds for which sampling is delayed after you start the session).

For additional information on this or other technical issue regarding the VTun e Performance Analyzer, visit: http://www.intel.com/cd/software/products/asmo-na/eng/index.htm .