Intel Looking To Move Their Low-Power Mode Daemon Into The Linux Kernel Source Tree
For years Intel has been developing the Low Power Mode Daemon "LPMD" to help their hybrid laptop and desktop CPUs deliver optimal power efficiency under Linux. Intel LPMD leverages hardware hints and other features for optimizing active idle power of the processor and putting the system into lower power modes where possible. This tool could soon call the Linux kernel source tree its new home.
Since its inception this user-space LPMD daemon has been developed by Intel engineers on GitHub. It's worked out well and back in November celebrated the v0.1 release ahead of the Core Ultra Series 3 "Panther Lake" debut. The Low Power Mode Daemon has since been picked up by some Linux distributions for enhancing the Intel Core Ultra Linux experience. Now though it's looking at potentially moving within the Linux kernel source tree.
Similar to how Turbostat and the x86_energy_perf_policy live within the Linux kernel source tree, Intel engineers are now looking at shifting LPMD's development into the kernel source tree. A set of patches were sent out today to adapt Intel LPMD to being a tool living within the Linux kernel source tree. Their argument for doing so is to "increase it's effectiveness through maintaining higher quality standards and better community cooperation." Though what that all entails remains to be seen. Intel LPMD development seems to have ticked lower this year with the GitHub commits not seeing anything new in one month and not too much activity this year outside of man page updates and build system updates.
The ten thousand line user-space daemon is now out for review/discussion via this mailing list thread while we await to see if its development moving forward will shift into the Linux kernel source tree.
Since its inception this user-space LPMD daemon has been developed by Intel engineers on GitHub. It's worked out well and back in November celebrated the v0.1 release ahead of the Core Ultra Series 3 "Panther Lake" debut. The Low Power Mode Daemon has since been picked up by some Linux distributions for enhancing the Intel Core Ultra Linux experience. Now though it's looking at potentially moving within the Linux kernel source tree.
Similar to how Turbostat and the x86_energy_perf_policy live within the Linux kernel source tree, Intel engineers are now looking at shifting LPMD's development into the kernel source tree. A set of patches were sent out today to adapt Intel LPMD to being a tool living within the Linux kernel source tree. Their argument for doing so is to "increase it's effectiveness through maintaining higher quality standards and better community cooperation." Though what that all entails remains to be seen. Intel LPMD development seems to have ticked lower this year with the GitHub commits not seeing anything new in one month and not too much activity this year outside of man page updates and build system updates.
"LPMD (Low Power Mode Daemon) is a program that helps increase mobile platform power efficiency based on current workload and user configuration. On newer systems hardware hints guide the decision making while on older ones software calculated system utilization can be used.
Depending on the workload LPMD manages active CPUs through cgroups, and if available balances different sysfs knobs and sliders to get the most power efficient result. Special emphasis is put on L-cores - low power CPUs management to get the most value out of newer hardware that supports such distinction.
Moving the development of LPMD to the kernel tree can increase it's effectiveness through maintaining higher quality standards and better community cooperation.
Notable differences between this patchset and the github version are
- reformatting the whole codebase in kernel coding style
- the autogen system is dropped in favour of a simpler Makefile
Other than that no functional changes should be introduced in comparison."
The ten thousand line user-space daemon is now out for review/discussion via this mailing list thread while we await to see if its development moving forward will shift into the Linux kernel source tree.