Linux boss Linus Torvalds merged earlier today several important patches for Intel CPU generally related to performance states (P-states) on Linux.
One of these includes a fix for a recently discovered Intel Turbo Boost Max Technology (ITMT) problem that was preventing the Alder Lake processors from performing to their fullest during an overclocked state. This bug is very reminiscent of the recent Ryzen CPPC2 bug on Windows 11 as it is related to task handling and fastest core prioritization. You can read about the ITMT issue in much more detail here.
The new merged patch contains fixes for three problems including one that fixes the ITMT issue with the help of Hardware-Controlled P-States (HWP). The other issues are related to hibernation. The patch description is given below. The ITMT bug has been bolded.
These address three issues in the intel_pstate driver and fix two problems related to hibernation.
Specifics:
- Make intel_pstate work correctly on Ice Lake server systems with out-of-band performance control enabled (Adamos Ttofari).
- Fix EPP handling in intel_pstate during CPU offline and online in the active mode (Rafael Wysocki).
- Make intel_pstate support ITMT on asymmetric systems with overclocking enabled (Srinivas Pandruvada).
- Fix hibernation image saving when using the user space interface based on the snapshot special device file (Evan Green).
- Make the hibernation code release the snapshot block device using the same mode that was used when acquiring it (Thomas Zeitlhofer)
This isn't the only Linux bug that Alder Lake possessed. There is also an existing Cluster Scheduler feature issue that is causing a massive performance downgrade on Linux 5.16 compared to previous kernels.
Source: Linux kernel git
