Installing and Managing HP-UX Virtual Partitions (includes A.04.02)

CPU, Memory, and IO Resources (A.03.xx)
CPU: CPU Monitor (formerly known as LPMC Monitor)
Chapter 7
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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 processors 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 processor 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 processor means that the OS will attempt to no longer use the processor by migrating all
threads off the processor. Deactivation of a processor is not persistent across an OS or system reboot; CPU
Monitor will deactivate the processor if it continues to detect problems.
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, the processors on the target socket are not
visible to either the OS in standalone mode or the OS instances of the virtual partitions. The deconfiguration
is persistent across system boots.
Note here two items:
• a deactivation of a processor does not mean a deconfiguration of its socket. The CPU Monitor is able to
determine whether the processor needs to be deactivated or whether it needs to take further action and
deconfigures the socket.
• 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 processors is the boot processor of each OS instance (the boot processor
has a logical instance of zero; otherwise, the OS would crash) 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 processors are available, the necessary number of
processors will be activated to replace the processors deactivated.
NOTE On a vPars system, for bound CPUs, the virtual partition boots with the CPU marked for
deconfiguration. For unbound CPUs, the Monitor will attempt to replaced the marked CPUs
with a working CPU; however, if no working CPUs are available, the Monitor automatically
reduces the unbound CPU number for that virtual partition in the vPars database and allows
the virtual partition to boot with the working CPUs.
The PA-8800s are dual-core sockets: they have two CPUs per socket. Deactivation happens on a
processor level, but deconfiguration happens at the socket level. If a socket is deconfigured,
both processors sharing the socket will be unavailable.