Re: [PATCH] cpufreq: Fix ondemand governor powersave_bias executiontime misuse

From: Andrew Morton
Date: Tue Mar 01 2011 - 20:08:04 EST


On Fri, 5 Nov 2010 11:19:51 -0400
Youquan Song <youquan.song@xxxxxxxxxxxxxxx> wrote:

> Ondemand governor use powersave_bias tunable to do aggressive power save by
> decrease CPU average frequency. The average frequency achieve by adjust low and
> high frequency's execution time proportion during one sample time interval.
>
> Current kernel, only the high frequency executes in time proportion, but the low
> frequency wrongly execute in one whole sample time interval when powersave_bias
> is set.
>
> The patch fix it by set low frequency execution time to it deserved.
>
> Signed-off-by: Youquan Song <youquan.song@xxxxxxxxx>
> ---
>
> diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c
> index c631f27..01d84fa 100644
> --- a/drivers/cpufreq/cpufreq_ondemand.c
> +++ b/drivers/cpufreq/cpufreq_ondemand.c
> @@ -666,6 +666,8 @@ static void do_dbs_timer(struct work_struct *work)
> } else {
> __cpufreq_driver_target(dbs_info->cur_policy,
> dbs_info->freq_lo, CPUFREQ_RELATION_H);
> + if (dbs_info->sample_type == DBS_SUB_SAMPLE)
> + delay = dbs_info->freq_lo_jiffies;
> }
> queue_delayed_work_on(cpu, kondemand_wq, &dbs_info->work, delay);
> mutex_unlock(&dbs_info->timer_mutex);

Where are we with this patch? Still needed in curent mainline?

Thnks.
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