linux-kernel - Re: [PATCH] cpufreq: intel_pstate: Fix cpuinfo_cur

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Message-ID: <7185077.O26hx51RqR@aspire.rjw.lan>
Date:   Mon, 24 Jul 2017 13:36:15 +0200
From:   "Rafael J. Wysocki" <rjw@...ysocki.net>
To:     Huaisheng HS1 Ye <yehs1@...ovo.com>
Cc:     "srinivas.pandruvada@...ux.intel.com" 
        <srinivas.pandruvada@...ux.intel.com>,
        "lenb@...nel.org" <lenb@...nel.org>,
        "viresh.kumar@...aro.org" <viresh.kumar@...aro.org>,
        "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] cpufreq: intel_pstate: Fix cpuinfo_cur_freq after performance governor changes

On Monday, July 24, 2017 05:43:14 AM Huaisheng HS1 Ye wrote:
> After commit 82b4e03e01bc (intel_pstate: skip scheduler hook when
> in "performance" mode) Software P-state control modes couldn't get
> dynamic value during performance mode,

Please explain what you mean here.

I guess you carried out some tests and the results were not as expected,
so what was the test?

> and it still in last value from powersave mode, so clear its value to get
> same behavior as Hardware P-state to avoid confusion.

And please explain why it should be fixed the way you've done that.

> Signed-off-by: Huaisheng Ye <yehs1@...ovo.com>
> ---
>  drivers/cpufreq/intel_pstate.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 6cd5035..c675626 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -2050,6 +2050,7 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy)
>  		 */
>  		intel_pstate_clear_update_util_hook(policy->cpu);
>  		intel_pstate_max_within_limits(cpu);
> +		cpu->sample.core_avg_perf = 0;
>  	} else {
>  		intel_pstate_set_update_util_hook(policy->cpu);
>  	}
>