HP-UX 11i June 2001 Release Notes

Process, Threads, Memory, and Kernel Parameters
Changes to mpctl() System Call (new at 11i original release)
Chapter 8180
All applications that use mpctl() to query the available processors and
locality domains to scale and bind for optimal performance will not
require any changes when the processor set functionality is made
available. The mpctl()’s existing commands will return information
about what processors are available for binding.
When processor set functionality becomes available, if the system is not
partitioned into more than one processor sets, no applications using the
mpctl() interface with current command requests will be affected.