Re: [RFC PATCH] x86/tsc: use topology_max_packages() in tsc watchdog check

[Dave Hansen]

On 10/17/22 06:29, Feng Tang wrote:
> +	if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
> +	    boot_cpu_has(X86_FEATURE_NONSTOP_TSC) &&
> +	    boot_cpu_has(X86_FEATURE_TSC_ADJUST) &&
> +	    topology_max_packages() <= 2)
> +		clocksource_tsc.flags &= ~CLOCK_SOURCE_MUST_VERIFY;

I couldn't help but notice the comment in here:

> void __init calculate_max_logical_packages(void)
> {
>         int ncpus;
> 
>         /*
>          * Today neither Intel nor AMD support heterogeneous systems so
>          * extrapolate the boot cpu's data to all packages.
>          */
>         ncpus = cpu_data(0).booted_cores * topology_max_smt_threads();
>         __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus);
>         pr_info("Max logical packages: %u\n", __max_logical_packages);
> }

Could you double check for me that the Alder Lake combination Core/Atom
CPUs don't count as "heterogeneous systems" in this case?