PAUSEOPT instructs the processor to enter an implementation-dependent optimized state. The instruction execution wakes up when the time-stamp counter reaches or exceeds the implicit EDX:EAX 64-bit input value. The instruction execution also wakes up due to the expiration of the operating system time-limit or by an external interrupt. PAUSEOPT is available on processors with X86_FEATURE_PAUSEOPT. PAUSEOPT allows the processor to enter a light-weight power/performance optimized state (C0.1 state) for a period specified by the instruction or until the system time limit. MSR_ZX_PAUSE_CONTROL MSR register allows the OS to enable/disable C0.2 on the processor and to set the maximum time the processor can reside in C0.1 or C0.2. By default C0.2 is disabled. A sysfs interface to adjust the time and the C0.2 enablement is provided in a follow up change.
The PR Link: https://gitee.com/anolis/cloud-kernel/pulls/6265