HP-UX 11i September 2001 Release Notes

Process, Threads, Memory, and Kernel Parameters
Changes to mpctl() System Call (new at 11i original release)
Chapter 8
142
Changes to mpctl() System Call (new at 11i original
release)
Some extensions are being made to mpctl() system call interface to pre-enable
processor set functionality in HP-UX 11i release.
The mpctl() interface provides command requests to query system information, like,
total number of processors and locality domains in the system, and ID of all processors
and locality domains. When processor set functionality is implemented in HP-UX, these
command requests will return information about the processor set of the calling thread,
and not the entire system.
A new set of mpctl() command options will be provided to query for system-wide
topology information, regardless of which processor set contains those resources. The
following seven new command requests will be provided in HP-UX 11i:
The new command requests are mapped to their current equivalent requests in 11i
release, so applications in 11i release will not be affected.
When the processor set functionality becomes available, applications that rely on
mpctl() to return system level information will need to be changed to use new
command requests. For these applications we recommend using the new commands in
the 11i release to avoid any issues when processor sets are available.
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.
New Request Its Equivalent in 11i
MPC_GETNUMSPUS_SYS MPC_GETNUMSPUS
MPC_GETFIRSTSPU_SYS MPC_GETFIRSTSPU
MPC_GETNEXTSPU_SYS MPC_GETNEXTSPU
MPC_GETNUMLDOMS_SYS MPC_GETNUMLDOMS
MPC_GETFIRSTLDOM_SYS MPC_GETFIRSTLDOM
MPC_GETNEXTLDOM_SYS MPC_GETNEXTLDOM
MPC_LDOMSPUS_SYS MPC_LDOMSPUS