Warnings about Accurate CPU Time Collection

The following table lists warning messages you may encounter when collecting data in the Accurate CPU time detection mode (enabled by default) and suggests solutions.

Warning

Cause and Possible Solution

Accurate CPU time detection was disabled. Another collection in this mode is already running on the system.

Cause

Another collection with accurate CPU time detection is running on the system or was not terminated properly.

Solution

Make sure the other collection has finished and try again. Only one VTune Amplifier collection can run with accurate CPU time detection on the system at a time.

Accurate CPU time detection was disabled. The NT Kernel Logger is already in use.

Cause

VTune Amplifier requires the Microsoft* NT Kernel Logger to capture precise CPU time data. The NT Kernel Logger is a system-wide resource which cannot be shared by different processes. Other tools, such as the Xperf utility of the Windows* Performance Tools Kit may use the NT Kernel Logger at the same time.

Solution

Make sure that other tools do not use the NT Kernel Logger and try again.

Accurate CPU time detection was disabled. Drive <drive name> has not enough disk space.

Cause

The temporary folder for storing accurate CPU time data is located on a drive with insufficient free space.

Solution

Make sure you have enough space on the drive. The free space must be not less than specified in the Collection data limit option on the Project Properties: Target tab.

Accurate CPU time detection was disabled. Administrative privileges are required.

Cause

VTune Amplifier requires administrative privileges to enable accurate CPU time detection.

Solution

Make sure you are running the collection as a local administrator.

Accurate CPU time detection was disabled. The temporary data path <full path to file> is longer than 1024 symbols.

Cause

VTune Amplifier uses temporary files to collect precise CPU time data. The length of the path to the temporary files cannot be longer than 1024 symbols.

Solution

Make sure the TEMP environment variable for the path to the temporary files is no longer than 1024 symbols.

Accurate CPU time detection was disabled. This mode is not supported on this OS.

Cause

Some operating systems may not support accurate CPU time detection. For the list of supported operating systems, please see the System Requirements section of the product Release Notes.

For more complete information about compiler optimizations, see our Optimization Notice.