-XX:ActiveProcessorCount

This HotSpot option is recognized by Eclipse OpenJ9™ for compatibility. Use this option to override the number of CPUs that the VM automatically detects and uses when creating threads for various subsystems.

Syntax

    -XX:ActiveProcessorCount=<n>

Where <n> is the number of CPUs.

Setting	Value	Default
<n>	1 or greater	There is no default value. This option is not enabled by default. If set to 0, there is no effect.

When you set this option the following line in a Java dump file is updated to indicate the number of CPUs specified:

2CIACTIVECPU Active CPUs

If this option is not set, the value for this line is 0 Active CPUs.