Hyper-Threading, available starting with HP-UX 11i v3 (B.11.31), enables you to use multiple execution threads per core. (Cores were formerly known as CPUs.) Each execution thread is a logical CPU.
Utilization is based on the usage of a core—not a logical CPU. For example, assume a four-core system has Hyper-Threading enabled so that it has eight logical CPUs. If the system has four processes, each consuming an entire logical CPU, the reported utilization depends on where those processes are. If the processes are on only two cores, the utilization is 50% (2/4). With the processes distributed across all four cores though, each process can consume an entire core, resulting in a utilization of 100%.
When fss groups are being used, gWLM disables Hyper-Threading for the default pset, where fss groups are created, to optimize workload performance.
When an SRD is undeployed, gwlmagent restores the lcpu_attr tunable to the value it had when the system booted. This value can be different from the value in effect before deployment if kctune was used without a reboot.
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