CPU capability change
When mainframe CPUs heat or cool, the Linux® kernel generates a uevent for all affected online CPUs.
You can read the CPU capability from the Capability and, if present, Secondary Capability fields in /proc/sysinfo.
The capability values are unsigned integers as defined in the system information block (SYSIB) 1.2.2 (see z/Architecture® Principles of Operation, SA22-7832). A smaller value indicates a proportionally greater CPU capacity. Beyond that, there is no formal description of the algorithm that is used to generate this value. The value is used as an indication of the capability of the CPU relative to the capability of other CPU models.