Intel Sends Out Revised Linux Patches For Directed Package Thermal Interrupts

Back in March was an initial patch series out of Intel for Linux support for Directed Package Thermal Interrupts as a new feature of recent Intel CPUs. There wasn't much to report over the past three months on this work but today a second iteration of the patches emerged on the Linux kernel mailing list.

As opposed to the current behavior of package-level thermal interrupts being broadcast to all CPU cores, Directed Package Thermal Interrupts allow for broadcasting to just one CPU core tasked for handling the package-wide events. In turn this feature will allow for reduced resource contention and can avoid needlessly waking up possible idle CPU cores.

So far I haven't seen any definitive indications what Intel CPUs support this feature. While the patches note that "newer" Intel CPUs support it, other indicators point it coming out with upcoming Nova Lake and Diamond Rapids processors.

The new v2 Linux patches for Directed Package Thermal Interrupt fix various bugs in the prior code and other code clean-ups.

Given the timing of this v2 patch series, we'll see how this latest round of code review goes and if this functionality makes to make it into the upcoming Linux v7.2 merge window.