Re: [Patch v3 1/8] perf/x86/intel: Remove anythread_deprecated bit from perf_capabilities

[Mi, Dapeng]

On 6/12/2026 5:46 PM, Peter Zijlstra wrote:
> On Fri, Jun 12, 2026 at 05:01:07PM +0800, Dapeng Mi wrote:
>> AnyThread mode deprecation is enumerated by CPUID.0AH:EDX[15] instead of
>> PERF_CAPABILITIES MSR. It's not a good practice to define a bit to
>> represent "anythread deprecation" in perf_capabilities. It leads to the
>> anythread_deprecated bit could be overwritten by the real value of
>> PERF_CAPABILITIES MSR, just like the below code in update_pmu_cap() does.
>>
>> ```
>> if (!intel_pmu_broken_perf_cap()) {
>> 	/* Perf Metric (Bit 15) and PEBS via PT (Bit 16) are hybrid enumeration */
>> 	rdmsrq(MSR_IA32_PERF_CAPABILITIES, hybrid(pmu, intel_cap).capabilities);
>> }
>> ```
>>
>> It leads to the anythread_deprecated bit is cleared to 0 and the "any"
>> attribute is incorrectly shown in the /sys/devices/cpu/format/ folder on
>> these support Perfmon v6 platforms, like Clearwater Forest.
>>
>> ```
>> $grep . /sys/devices/cpu/format/*
>> /sys/devices/cpu/format/acr_mask:config2:0-63
>> /sys/devices/cpu/format/any:config:21
>> /sys/devices/cpu/format/cmask:config:24-31
>> ```
>>
>> So remove the anythread_deprecated bit from perf_capabilities structure
>> and directly depends on CPUID.0AH:EDX[15] to judge if anythread is
>> deprecated.
> Again, no markdown please. I've stripped it from these patches.

My bad. Thanks a lot.

BTW, Peter, have you pull these patches? I didn't see them in perf/core or
perf/urgent branches. Sashiko reports a defect about "Patch 5/8:
perf/x86/intel: Validate the return value of intel_pmu_init_hybrid()". If
not, I would post a v4 patchset to fix the defect. Thanks.