Re: [RESEND PATCH] perf/x86/intel: Fix unchecked MSR access error for Alder Lake N

[Peter Zijlstra]

On Thu, Aug 18, 2022 at 11:15:30AM -0700, kan.liang@xxxxxxxxxxxxxxx wrote:

> The Alder Lake N only has e-cores. The X86_FEATURE_HYBRID_CPU flag is
> not set. The perf cannot retrieve the correct CPU type via
> get_this_hybrid_cpu_type(). The model specific get_hybrid_cpu_type() is
> hardcode to p-core. The wrong CPU type is given to the PMU of the
> Alder Lake N.

If ADL-N isn't in fact a hybrid CPU, then *WHY* are we running
init_hybrid_pmu() and setting up all that nonsense?

That is, wouldn't the right thing be to remove ALDERLAKE_N from the rest
of {ALDER,RAPTOP}LAKE and create a non-hybrid PMU setup for it?