HP-UX Virtual Partitions Administrator's Guide (includes A.03.04) (previously titled Installing and Managing HP-UX Virtual Partitions)

CPU, Memory, and I/O Resources (A.05.xx)
CPU: CPU Monitor (formerly known as LPMC Monitor)
Chapter 6
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CPU: CPU Monitor (formerly known as LPMC Monitor)
The CPU Monitor (a part of the diagnostic tool Event Monitor Services (EMS) and not a part of the vPars
Monitor) is designed to Monitor cache parity errors within the CPUs on the system. With its Dynamic
Processor Resilience (DPR), if the CPU Monitor detects a pre-determined number of errors, the CPU Monitor
will deactivate a CPU for the current boot session. If the problems are severe enough, the CPU Monitor will
deconfigure the socket for the next boot of the system.
Deactivation of a CPU means that the OS will attempt to no longer use the CPU by migrating all threads off
the CPU. Deactivation of a CPU is not persistent across an OS or system reboot.
Deconfiguration of a socket means that the EMS issues a firmware call, marking the socket for
deconfiguration on the next system boot. On the next system boot, none of the cores in the target socket are
visible to either the OS in standalone mode or the OS instances of the virtual partitions. The deconfiguration
is persistent across system boots.
Note the following two items:
• A deactivation of a CPU does not mean a deconfiguration of its socket. The CPU Monitor is able to
determine whether the CPU needs to be deactivated or whether it needs to take further action and
deconfigure the socket.
• A reboot of a virtual partition is not the same as a reboot of the system (the entire box or nPartition).
The exceptions to the deactivation of CPUs are the boot processor of each OS instance (the boot processor has
a logical instance of zero) and the last CPU in a cell or nPartition. The exception to the deconfiguration of
sockets is that the last remaining socket will not be deconfigured (otherwise, the system could not boot).
If any spare iCAP (formerly known as iCOD) or PPU CPUs are available, the necessary number of CPUs will
be activated to replace the CPUs deactivated.
NOTE On a vPars system, when a virtual partition goes down and contains a deconfigured or
deactivated CPU, the Monitor will try to decommission the CPU from use and replace it with
another good CPU if possible. If this is not possible, the Monitor will not allow the partition to
boot until the deconfigured or deactivated CPU can be taken out of use. Following are some
cases where the Monitor may not allow the virtual partition to boot:
• There is a deconfigured or deactivated CPU which has been reserved for the partition as
part of the total (cpu:: num ) request and Monitor does not have any free CPUs with which
to replace it. To correct this, you can delete CPUs from other partitions or from this
partition.
• There is a deconfigured or deactivated CPU that has been bound to the partition by
hardware path (cpu: hw_path ) which the Monitor is not able to replace with another
available CPU. To correct this, you can remove the CPU specified by hardware path using
-d cpu:hw_path to allow the deconfigured or deactivated CPU to be decommissioned and
replaced with another (working) CPU.
• There is a deconfigured CPU which has been reserved for the partition as part of a CLP
request (cell: cell_ID :cpu:: num ) and there are no free CLPs in that cell. To correct this, you
can make available CPUs from that cell by deleting the CPUs that are part of this cell from
other partitions or delete the CPUs from the cell in this partition.