Re: [PATCH v2 3/3] PM: Introduce Intel PowerClamp Driver
From: Joe Perches
Date: Mon Nov 26 2012 - 18:27:15 EST
On Mon, 2012-11-26 at 06:37 -0800, Jacob Pan wrote:
> Intel PowerClamp driver performs synchronized idle injection across
> all online CPUs. The goal is to maintain a given package level C-state
> ratio.
trivial notes:
> diff --git a/drivers/thermal/intel_powerclamp.c b/drivers/thermal/intel_powerclamp.c
You should still add #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
before any include so that all messages are prefixed with powerclamp:
> +
> +/* #define DEBUG */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
[]
> +static void adjust_compensation(int target_ratio, unsigned int win)
> +{
> + int delta;
It'd be shorter code to use a temporary like
struct powerclamp_calibration_data *d = &cal_data[target_ratio];
> +
> + /*
> + * adjust compensations if confidence level has not been reached or
> + * there are too many wakeups during the last idle injection period, we
> + * cannot trust the data for compensation.
> + */
> + if (cal_data[target_ratio].confidence >= CONFIDENCE_OK ||
> + atomic_read(&idle_wakeup_counter) >
> + win * num_online_cpus())
> + return;
> +
> + delta = set_target_ratio - current_ratio;
> + /* filter out bad data */
> + if (delta >= 0 && delta <= (1+target_ratio/10)) {
> + if (cal_data[target_ratio].steady_comp)
> + cal_data[target_ratio].steady_comp =
> + roundup(delta+
> + cal_data[target_ratio].steady_comp,
> + 2)/2;
so that this fits on a single line and becomes:
if (d->steady_comp)
d->steady_comp = roundup(delta + d->steady_comp, 2) / 2;
etc.
What clamps target_ratio to the correct range?
I briefly scanned the code but didn't spot it.
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