-XX:ActiveProcessorCount

This Hotspot option is recognized by 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.