Re: [PATCH PATCH v2 2/9] cpufreq: intel_pstate: Use topology_cpu_type()

From: Rafael J. Wysocki
Date: Mon Jul 01 2024 - 13:09:13 EST


On Thu, Jun 27, 2024 at 10:44 PM Pawan Gupta
<pawan.kumar.gupta@xxxxxxxxxxxxxxx> wrote:
>
> Intel pstate driver uses hybrid_get_type() to get the cpu-type of a given
> CPU. It uses smp_call_function_single() which is sub-optimal. Avoid it by
> using topology_hw_cpu_type(cpu) that returns the cached cpu-type.
>
> Suggested-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@xxxxxxxxxxxxxxx>
> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

and I'm assuming that it will be routed along with the rest of the series.

Thanks!

> ---
> drivers/cpufreq/intel_pstate.c | 14 +++-----------
> 1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 15de5e3d96fd..0a1e832c7536 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -1956,24 +1956,16 @@ static int knl_get_turbo_pstate(int cpu)
> return ret;
> }
>
> -static void hybrid_get_type(void *data)
> -{
> - u8 *cpu_type = data;
> -
> - *cpu_type = get_this_hybrid_cpu_type();
> -}
> -
> static int hwp_get_cpu_scaling(int cpu)
> {
> - u8 cpu_type = 0;
> + u8 cpu_type = topology_hw_cpu_type(cpu);
>
> - smp_call_function_single(cpu, hybrid_get_type, &cpu_type, 1);
> /* P-cores have a smaller perf level-to-freqency scaling factor. */
> - if (cpu_type == 0x40)
> + if (cpu_type == X86_HW_CPU_TYPE_INTEL_CORE)
> return hybrid_scaling_factor;
>
> /* Use default core scaling for E-cores */
> - if (cpu_type == 0x20)
> + if (cpu_type == X86_HW_CPU_TYPE_INTEL_ATOM)
> return core_get_scaling();
>
> /*
>
> --