Re: [PATCH v2] x86/tsc: Extend watchdog check exemption to 4-Sockets platform

[Dave Hansen]

On 10/13/22 06:12, Feng Tang wrote:
> @@ -1217,7 +1217,7 @@ static void __init check_system_tsc_reliable(void)
>  	if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC) &&
>  	    boot_cpu_has(X86_FEATURE_NONSTOP_TSC) &&
>  	    boot_cpu_has(X86_FEATURE_TSC_ADJUST) &&
> -	    nr_online_nodes <= 2)
> +	    nr_online_nodes <= 4)
>  		tsc_disable_clocksource_watchdog();

I still don't think we should perpetuate this hack.

This just plain doesn't work in numa=off numa=fake=... or presumably in
cases where NUMA is disabled in the firmware and memory is interleaved
across all sockets.

It also presumably doesn't work on two-socket systems that have
Cluster-on-Die or Sub-NUMA-Clustering where a single socket is chopped
up into multiple nodes.