Re: [PATCH 08/13] xenpm: Print HWP parameters

[Jan Beulich <jbeulich@suse.com>]

On 03.05.2021 21:28, Jason Andryuk wrote:
> --- a/tools/misc/xenpm.c
> +++ b/tools/misc/xenpm.c
> @@ -708,6 +708,43 @@ void start_gather_func(int argc, char *argv[])
>      pause();
>  }
>  
> +static void calculate_hwp_activity_window(const xc_hwp_para_t *hwp,
> +                                          unsigned int *activity_window,
> +                                          const char **units)
> +{
> +    unsigned int mantissa = hwp->activity_window & 0x7f;
> +    unsigned int exponent = ( hwp->activity_window >> 7 ) & 0x7;

Excess blanks inside the parentheses.

> +    unsigned int multiplier = 1;
> +
> +    if ( hwp->activity_window == 0 )
> +    {
> +        *units = "hardware selected";
> +        *activity_window = 0;
> +
> +        return;
> +    }
> +
> +    if ( exponent >= 6 )
> +    {
> +        *units = "s";
> +        exponent -= 6;
> +    }
> +    else if ( exponent >= 3 )
> +    {
> +        *units = "ms";
> +        exponent -= 3;
> +    }
> +    else
> +    {
> +        *units = "us";
> +    }
> +
> +    for ( unsigned int i = 0; i < exponent; i++ )

This requires the compiler to default to C99 mode, which I don't
think we enforce just yet.

> +        multiplier *= 10;
> +
> +    *activity_window = mantissa * multiplier;
> +}
> +
>  /* print out parameters about cpu frequency */
>  static void print_cpufreq_para(int cpuid, struct xc_get_cpufreq_para *p_cpufreq)
>  {
> @@ -777,6 +814,40 @@ static void print_cpufreq_para(int cpuid, struct xc_get_cpufreq_para *p_cpufreq)
>                 p_cpufreq->scaling_cur_freq);
>      }
>  
> +    if ( strcmp(p_cpufreq->scaling_governor, "hwp-internal") == 0 )
> +    {
> +        const xc_hwp_para_t *hwp = &p_cpufreq->u.hwp_para;
> +
> +        printf("hwp variables        :\n");
> +        printf("  hardware limits    : lowest [%u] most_efficient [%u]\n",
> +               hwp->hw_lowest, hwp->hw_most_efficient);
> +        printf("  hardware limits    : guaranteed [%u] highest [%u]\n",
> +               hwp->hw_guaranteed, hwp->hw_highest);
> +        printf("  configured limits  : min [%u] max [%u] energy_perf [%u]\n",
> +               hwp->minimum, hwp->maximum, hwp->energy_perf);
> +
> +        if ( hwp->hw_feature & XEN_SYSCTL_HWP_FEAT_ENERGY_PERF )
> +        {
> +            printf("  configured limits  : energy_perf [%u%s]\n",
> +                   hwp->energy_perf,
> +                   hwp->energy_perf ? "" : " hw autonomous");
> +        }
> +
> +        if ( hwp->hw_feature & XEN_SYSCTL_HWP_FEAT_ACT_WINDOW )
> +        {
> +            unsigned int activity_window;
> +            const char *units;
> +
> +            calculate_hwp_activity_window(hwp, &activity_window, &units);
> +            printf("  configured limits  : activity_window [%u %s]\n",
> +                   activity_window, units);
> +        }
> +
> +        printf("  configured limits  : desired [%u%s]\n",
> +               hwp->desired,
> +               hwp->desired ? "" : " hw autonomous");
> +    }

I suppose output readability would improve if you didn't repeat
"hardware limits :" and "configured limits :" on continuation-like
lines, but rather simply indented by enough spaces.

Also again please again omit an unnecessary pair of braces.

Jan