Intel Alder Lake Performance Fix To Be Backported To Linux 5.15 LTS
A Canonical kernel engineer is now proposing an Intel P-State performance fix for latest-generation Intel Alder Lake processors be back-ported to the Linux 5.15 LTS series. In turn this should then be picked up by Ubuntu 22.04's kernel build moving forward and others on this latest long-term support series for Linux.
This follows last week's Phoronix article, Intel Alder Lake Users On Ubuntu 22.04 LTS Will Want To Switch To A Newer Kernel. In there I showed how Linux 5.16 and newer perform significantly better overall than Linux 5.15 and prior on the likes of the Core i9 12900K and other Alder Lake hybrid CPUs sporting a mix of P and E cores.
As explained in the article, one of the main fixes in Linux 5.16 is this patch from November for the Intel P-State driver for ITMT support on "overclocked" systems (in this case, overclocked can be just the optimized modes for memory profiles and the like and not conventional overclocking of the CPU speed itself). While that patch was basically three lines of new code and rather straight-forward, it was never back-ported to any Linux kernel stable series but left as v5.16+.
Now after laying all of that out publicly and showing the significant gains of v5.16+ compared to Ubuntu 22.04's stock Linux 5.15 kernel, that patch in question is working its way to a future Linux 5.15 point release.
Canonical engineer Dimitri John Ledkov this morning sent out that November patch on the stable mailing list in looking to land it for the v5.15 series. Thus assuming no objections are raised (which shouldn't be the case as it's rather straight-forward change), it should appear soon in an upstream Linux 5.15 point release for all to enjoy -- including Ubuntu 22.04 in pulling down patches from upstream and then appearing in a stable release update for the Jammy Jellyfish.
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Update: The patch is now queued for the 5.15 stable series!