Linux 7.1 Adds SoC Slider Support To x86_energy_perf_policy Utility
One of the last feature pulls merged by Linus Torvalds prior to tagging Linux 7.1-rc1 this weekend were some power utility updates for those tools living within the kernel source tree.
The x86_energy_perf_policy utility that is part of the Linux kernel for managing energy and performance policies was updated as part of this late merge for Linux 7.1. With the x86_energy_perf_policy utility there is now support for reading and writing SoC slider parameters, which is a new Intel SoC feature initially in place for Intel Core Ultra Series 3 "Panther Lake" systems.
Last year the Intel int340x thermal driver was wired up for enabling the SoC slider with Panther Lake for indicating the system-wide energy performance hint as well as the ability to override the default power behavior if wanting to improve the SoC's power efficiency further. The int340x thermal driver has been exposing those SoC slider attributes via sysfs while for Linux 7.1 there is integration with the x86_energy_perf_policy tool for more easily managing as your SoC power/performance preference.
The support added to x86_energy_perf_policy by Intel engineer Kaushlendra Kumar explains:
That SoC slider integration is now merged and part of the Linux 7.1-rc1 kernel. The Turbostat utility was also updated with that merge to now display the Hyper Threading (HT) / SMT sibling in the CPU# order, a Module-ID column, and other fixes.
The x86_energy_perf_policy utility that is part of the Linux kernel for managing energy and performance policies was updated as part of this late merge for Linux 7.1. With the x86_energy_perf_policy utility there is now support for reading and writing SoC slider parameters, which is a new Intel SoC feature initially in place for Intel Core Ultra Series 3 "Panther Lake" systems.
Last year the Intel int340x thermal driver was wired up for enabling the SoC slider with Panther Lake for indicating the system-wide energy performance hint as well as the ability to override the default power behavior if wanting to improve the SoC's power efficiency further. The int340x thermal driver has been exposing those SoC slider attributes via sysfs while for Linux 7.1 there is integration with the x86_energy_perf_policy tool for more easily managing as your SoC power/performance preference.
The support added to x86_energy_perf_policy by Intel engineer Kaushlendra Kumar explains:
"Add support for reading and writing SOC slider parameters and platform profile via sysfs in x86_energy_perf_policy.
New command-line options:
--soc-slider-balance [value]
--soc-slider-offset [value]
--platform-profile [name]
These options allow control of the processor thermal SOC slider balance and offset through the processor_thermal_soc_slider module, as well as the platform profile class interface.
When no update flags are set, the tool now also prints the current SOC slider and platform profile values alongside existing MSR output."
That SoC slider integration is now merged and part of the Linux 7.1-rc1 kernel. The Turbostat utility was also updated with that merge to now display the Hyper Threading (HT) / SMT sibling in the CPU# order, a Module-ID column, and other fixes.