linux-kernel - Re: [PATCH] cpufreq: intel_pstate: Clean up aperf_mperf

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Date:   Wed, 15 Jul 2020 15:17:40 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:     Linux PM <linux-pm@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: Re: [PATCH] cpufreq: intel_pstate: Clean up aperf_mperf_shift
 description

On Wed, 15 Jul 2020, Rafael J. Wysocki wrote:

> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> The kerneldoc description of the aperf_mperf_shift field in
> struct global_params is unclear and there is a typo in it, so
> simplify it and clean it up.
> 
> Reported-by: Lee Jones <lee.jones@...aro.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
>  drivers/cpufreq/intel_pstate.c |    4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> Index: linux-pm/drivers/cpufreq/intel_pstate.c
> ===================================================================
> --- linux-pm.orig/drivers/cpufreq/intel_pstate.c
> +++ linux-pm/drivers/cpufreq/intel_pstate.c
> @@ -202,9 +202,7 @@ struct global_params {
>   * @pstate:		Stores P state limits for this CPU
>   * @vid:		Stores VID limits for this CPU
>   * @last_sample_time:	Last Sample time
> - * @aperf_mperf_shift:	Number of clock cycles after aperf, merf is incremented
> - *			This shift is a multiplier to mperf delta to
> - *			calculate CPU busy.
> + * @aperf_mperf_shift:	APERF vs MPERF counting frequency difference
>   * @prev_aperf:		Last APERF value read from APERF MSR
>   * @prev_mperf:		Last MPERF value read from MPERF MSR
>   * @prev_tsc:		Last timestamp counter (TSC) value

Definitely clearer.

Reviewed-by: Lee Jones <lee.jones@...aro.org>

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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