Intel has submitted patches to simplify the energy model in the Linux P-State driver, targeting hybrid CPUs without simultaneous multithreading support. This update focuses on improving power management for Lunar Lake systems-on-chips and upcoming Panther Lake processors. The changes aim to optimize performance and battery life in Linux-based devices.
Intel engineer Rafael Wysocki, maintainer of the Linux power management subsystem, recently posted a patch set to streamline the Intel P-State driver's energy model. This simplification applies to newer Core Ultra hybrid systems, which combine performance-oriented P-cores and efficiency-focused E-cores but lack simultaneous multithreading (SMT) support.
The adjustments assume uniform energy costs across core types in the absence of SMT, reducing unnecessary complexity from older models designed for threaded setups. Wysocki explained that for platforms like Lunar Lake, which do not support SMT, the energy model can be pared down without sacrificing accuracy in power efficiency predictions. These patches, reported by Phoronix, build on prior efforts in energy-aware scheduling (EAS) adapted specifically for the P-State driver in Lunar Lake.
By better distributing tasks between P-cores and E-cores, the changes seek to enhance energy efficiency, leading to more predictable CPU frequency scaling. This could improve battery life in mobile devices and reduce thermal overhead in data centers. The initiative reflects Intel's broader push to strengthen Linux support for its hardware amid competition from AMD's Ryzen processors.
The patches are under review for future Linux kernel versions, with potential benefits for developers tuning power profiles and reducing scheduler computational load. As Panther Lake nears, further refinements may incorporate open-source community feedback, emphasizing iterative improvements in hybrid CPU performance.