Re: [PATCH v2 2/2] x86/cpuid: Update bitfields to x86-cpuid-db v3.1

From: Ingo Molnar

Date: Thu Jun 04 2026 - 03:43:36 EST



* Maciej Wieczor-Retman <m.wieczorretman@xxxxx> wrote:

> From: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx>
>
> Update leaf_types.h to version 3.1, as generated by x86-cpuid-db.
>
> Summary of the v3.1 changes:
>
> * Fix a few typos that were found during the kernel CPUID data model
> review. Also include fixes found using an LLM agent review.
>
> * Rename thrd_director_nclasses to hw_feedback_nclasses as it's the
> name used in Intel SDM.

The following detail from the first submission got lost:

> @@ -246,7 +246,7 @@ struct leaf_0x6_0 {
> - thrd_director_nclasses : 8, // Number of classes, Intel thread director
> + hw_feedback_nclasses : 8, // Number of Intel Thread Director classes
>
> Note, for CPUID(0x6) thrd_director_nclasses, it was written this way
> because the project does not support bitfields names with more letters.

What does this mean exactly, is there a string length limit on the
field name in 'struct leaf_0x6_0'? What is the limit?

Thanks,

Ingo