CPU Utilization

You can calculate CPU utilization for the operating system (OS) by determining how much time the OS spends in the IDLE state over a period of time. The device goes idle when the kernel calls OEMIdle.

The OAL must update the following three global variables to support OEMIdle:

• curridlehigh
• curridlelow
• idleconv

Idleconv is the conversion to be applied to the 64-bit time value stored in curridlehigh and curridlelow to return a millisecond value. If curridlehigh and curridlelow are based on milliseconds then idleconv is set to 1. The values of curridlehigh and curridlelow are always increasing and the increase is based on the amount of time that the device will idle or on the amount of time that the device idled before being wakened. From an application, a call to GetIdleTime will return the OAL values.

See Also

Interactions between OEMIdle and the Thread Timer | Sample Platform Implementations of OEMIdle | Enabling Power Management

Last updated on Wednesday, April 13, 2005

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