Re: [PATCH] Handle Ice Lake MONITOR erratum

* Dave Hansen dave.hansen@intel.com wrote:

On 4/21/25 23:46, Ingo Molnar wrote:

...

...

/*

• • These CPUs have buggy MWAIT/MONITOR implementations that
• • usually manifest as hangs or stalls at boot.
• */

+#define MWAIT_VFM(_vfm) \

• X86_MATCH_VFM_FEATURE(_vfm, X86_FEATURE_MWAIT, 0)

+static const struct x86_cpu_id monitor_bug_list[] = {

• MWAIT_VFM(INTEL_ATOM_GOLDMONT),
• MWAIT_VFM(INTEL_LUNARLAKE_M),
• MWAIT_VFM(INTEL_ICELAKE_X), /* Erratum ICX143 */
• {},

+};

While it's just an internal helper, macro names should still be intuitive:

s/MWAIT_VFM /VFM_MWAIT_BUG

The current convention is to end with the thing that's being matched, like "_FEATURE" or "_VFM" in the X86_MATCH*() macros. That's why I ordered it the way I did.

As for including "BUG", the _macro_ doesn't match CPUs with the bug. It's just matching CPUs with the specified VFM that have MWAIT. It could (theoretically) get used for non-bug things so I don't think it's intuitive to put "BUG" in the name.

Oh, that makes sense - objection withdrawn.

Thanks,

Ingo