Abstract: According to one embodiment, a method comprises system firmware instructing a system's operating system to idle a processor, and responsive to the instructing, the operating system idling the processor and returning control over the processor to the system firmware. According to one embodiment, a method comprises detecting loss of lockstep (LOL) for a processor module in a system, and responsive to the detecting LOL for the processor module, system firmware instructing an operating system to idle the processor module.

Abstract: According to one embodiment, a method comprises, responsive to detection of loss of lockstep (LOL) for a processor module in a system, firmware requesting an operating system to idle the processor module. The method further comprises the operating system idling the processor module and returning control of the processor module to the firmware. According to one embodiment, a method comprises an operating system idling a processor module for which A loss of lockstep (LOL) is detected, and system firmware receiving control of the processor module. The method further comprises the system firmware determining whether a LOL was detected for the processor module, and if determined that LOL was detected for the processor module, the system firmware resetting the processor module to reestablish lockstep for the processor module.

Abstract: According to one embodiment, a method comprises, responsive to detection of loss of lockstep (LOL) for a processor module in a system, setting status information stored to the system for the processor module to indicate that the processor module has an error. The method further comprises reestablishing lockstep for the processor module without shutting down the system's operating system, and updating the status information for the processor module to indicate that the processor module no longer has the error. The method further comprises causing the system's operating system to recognize that the processor module having its lockstep reestablished is available for processing.