All recent Intel Atom cores support the PTWRITE instruction which is used for fine-grained execution trace recording, but so far none of the other Intel cores have this feature. The new Alder Lake models (e.g., i7-12700) have a mix of performance cores (p-cores) and efficient cores (e-cores). The p-cores have the typical performance architecture without PTWRITE, but the e-cores are based on Atom, and the support reps at Intel have confirmed that the e-cores do have the PTWRITE feature.

Now I'm wondering if the Linux kernel can enable PTWRITE when it is not available on all the cores. If so, how does it work? Normally the caps for Intel PT are global to the processor, so... have they been partitioned for Alder Lake to account for differences among the cores? My guess is that only the lowest-common-denominator of features is supported by the kernel, but it's an expensive experiment to find out "the hard way".