Re: [PATCH v8 8/9] x86/mtrr: Avoid repeated save of MTRRs on boot-time CPU bringup

[Thomas Gleixner <tglx@xxxxxxxxxxxxx>]

On Thu, Feb 09 2023 at 15:41, Usama Arif wrote:
>  void mtrr_save_state(void)
>  {
> +	static bool mtrr_saved;
>  	int first_cpu;
>  
>  	if (!mtrr_enabled())
>  		return;
>  
> +	if (system_state < SYSTEM_RUNNING) {
> +		if (!mtrr_saved) {
> +			mtrr_save_fixed_ranges(NULL);
> +			mtrr_saved = true;
> +		}
> +		return;
> +	}
> +
>  	first_cpu = cpumask_first(cpu_online_mask);
>  	smp_call_function_single(first_cpu, mtrr_save_fixed_ranges, NULL, 1);

So why is this relevant after the initial bringup? The BP MTRRs have
been saved already above, no?

Thanks,

        tglx