Support for Intel Thread Director technology is a “battlefield” on which Linux has always asserted itself. The goal of the “conductor” designed by Intel and integrated into its latest generation processors is to optimize the management of processing tasks on systems with hybrid core architectures. The main objective of Thread Director is in fact to improve the energy efficiency and overall performance of the system, especially with those processors that exploit, within the same packagecore E and core P (the former low energy consumption, the latter performance-oriented).
Intel Thread Director support on Linux
Hybrid management of the cores integrated into modern machines CPU Intel Core, with a combination of P and E cores, is now well established in the Linux environment. Thread Director support has been integrated with various improvements applied over time to the Linux kernel, in order to better manage the distribution of tasks and workloads between P and E cores.
The news is that Intel software engineers first proposed and then obtained the addition of a series of new features at the Linux kernel level. patch to support the so-called Thread Director Virtualization. The goal is to improve the virtual machine performance operating on Intel hybrid platforms.
The main use case is about using a system host Linux on Intel Core hardware running one or more virtual machines guest con Microsoft Windows.
With Intel patches integrated into the Linux kernel, Intel Core processors (12th to 15th generation inclusive) can handle the workload on cores P and E, also recording a 14% performance increase compared to the previous configuration (before the low level intervention). To highlight the encouraging results, the benchmark 3DMark run on a virtual machine guest Windows.
The requirements to make Windows 11 even faster on virtual machines created on Linux hosts
Sifting through the documentation shared by Ricardo Neri (Intel) we learn that for improve performance of Windows 11 in a virtual machine created on a Linux system, you not only need to enable Thread Director but also have some additional requirements. Hardware P-state (HWP) e Collaborative Processor Performance Control (CPPC) are mechanisms that manage and optimize performance of the processor based on thermal needs of the system. In essence, HWP and CPPC are thermal management features that help keep the processor temperature within safe limits.
However, Neri states that it is possible to emulate (or simulate) these thermal supports by setting a fictitious value at the Virtual Machine Monitor (VMM), which is the software component that manages virtual machines on a physical system. This expedient allows you to expose the behavior of virtual HWPs and CPPCs, even in the absence of real hardware support.
The measure in question is useful to ensure that, even if the physical system does not have certain thermal supports, the virtual machine can still benefit from workload optimization based on Thread Director.