linux-kernel - Re: [PATCH v1] PM: EM: Decrement policy counter

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Message-ID: <8ee5dfd0-558b-5ad6-63d2-b142550f04a3@arm.com>
Date:   Tue, 26 Apr 2022 16:40:32 +0100
From:   Vincent Donnefort <vincent.donnefort@....com>
To:     Pierre Gondois <pierre.gondois@....com>,
        linux-kernel@...r.kernel.org
Cc:     cristian.marussi@....com, Ionela.Voinescu@....com,
        Dietmar.Eggemann@....com, "Rafael J. Wysocki" <rafael@...nel.org>,
        Pavel Machek <pavel@....cz>, Len Brown <len.brown@...el.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        linux-pm@...r.kernel.org
Subject: Re: [PATCH v1] PM: EM: Decrement policy counter

On 26/04/2022 15:44, Pierre Gondois wrote:
> From: Pierre Gondois <Pierre.Gondois@....com>
> 
> Fixes: e458716a92b57 ("PM: EM: Mark inefficiencies in CPUFreq")
> In the above commit, cpufreq_cpu_get() is called without
> a cpufreq_cpu_put(), permanently increasing the reference counts
> of the policy struct.
> Decrement the reference count once the policy struct is not used
> anymore.


Not sure if the tag there will be caught properly. Usually it goes on
top of the Signed-off-by.

While at it:

Reviewed-by: Vincent Donnefort <vincent.donnefort@....com>

Thanks for fixing this.

> 
> Tested-by: Cristian Marussi <cristian.marussi@....com>
> Signed-off-by: Pierre Gondois <pierre.gondois@....com>
> ---
>   kernel/power/energy_model.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
> index 0153b0ca7b23..6219aaa454b5 100644
> --- a/kernel/power/energy_model.c
> +++ b/kernel/power/energy_model.c
> @@ -259,6 +259,8 @@ static void em_cpufreq_update_efficiencies(struct device *dev)
>   			found++;
>   	}
>   
> +	cpufreq_cpu_put(policy);
> +
>   	if (!found)
>   		return;
>