When Intel launched its Alder Lake structure again at its 2021 Architecture Day event, The agency touted its efficiency optimization surrounding Microsoft’s House windows 11. However, The identical Can’t be said for Linux it seems. As Simply a few days in the past, we reported on an Alder Lake bug that was inflicting efficiency loss on the upcoming Linux 5.16 kernel; and yesterday, A mannequin new patch was submitted For An further problem detected on Alder Lake.
The mannequin new problem revolves round Collaborative Processor Performance Administration (CPPC) or quickest core prioritization And will be very Harking again to the current Ryzen CPPC2 bug on House windows 11.
Alder Lake has A mannequin new Performance Hybrid structure consisting of each “Huge” cores (E-core) and “Hugeger” cores (P-core), however presently, Linux is unable to decide these individually when the system is in an overclocked state. As a consequence, the OS assigns equal efficiency potential to All of the cores Regardless of Whether or not or not they’re P-cores or E-cores.
This Leads to a battle with Intel’s Turbo Increase Max Know-how (ITMT) which assists to schedule precedence single-threaded workloads on the quickest cores. However, since all cores now have equal efficiency values assigned, ITMT fails to work in such overclocked methods.
The upcoming patch hopes To restore this drawback with The assist of MSR_HWP_CAPABILITIES or Hardware-Administrationled P-States (HWP) every time out there. However the patch would in all probability not work on older legacy methods lacking MSR_HWP_CAPABILITIES.
by way of Phoronix