Hi Salvatore, One of my colleagues supplied this explanation:
""' intel_idle is a kernel module that implements specialized logic for handling CPU idle/sleep states. This logic is optimized for Intel CPUs to achieve better results than what is possible through the ACPI C-state mechanism. For example, intel_idle can specify C-state target residency different than 2*latency. Better results here means lower wakeup latency (vs ACPI) while not compromising performance and power savings. Without intel_idle, many VMs will use HLT for putting the CPU cores to sleep, which will only put Intel CPUs in a shallow sleep state, thus wasting power that could otherwise be saved or used by other cores by boosting higher. Importantly, intel_idle requires the presence of MWAIT instruction. For some time, this hasn't been available in virtualized environments, but it is now relatively widespread: - GCE: https://cloud.google.com/compute/docs/cpu-platforms#frequency_behavior - AWS: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/processor_state_control.html Note this module is already present and used in many other cloud distro images: Ubuntu, CentOS, RHEL, Rocky, CentOS to name a few. """ So in summary, the benefits to the Debian cloud kernel user are lower wakeup latency and the ability to boost other cores higher by putting some cores into a deeper sleep state (making power and thermal budget available to adjacent cores). Kind regards, Andrew Jorgensen
