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Date:   Mon, 23 Nov 2020 10:28:39 +0000
From:   Quentin Perret <qperret@google.com>
To:     Pavankumar Kondeti <pkondeti@codeaurora.org>
Cc:     linux-kernel@vger.kernel.org,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Lukasz Luba <lukasz.luba@arm.com>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: Re: [PATCH] PM / EM: Micro optimization in em_pd_energy
Message-ID: <20201123102839.GB447993@google.com>
References: <1606126679-11799-1-git-send-email-pkondeti@codeaurora.org>
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In-Reply-To: <1606126679-11799-1-git-send-email-pkondeti@codeaurora.org>
Precedence: bulk

Hi Pavan,

On Monday 23 Nov 2020 at 15:47:57 (+0530), Pavankumar Kondeti wrote:
> When the sum of the utilization of CPUs in a power domain is zero,

s/power/performance

> return the energy as 0 without doing any computations.
> 
> Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
> ---
>  include/linux/energy_model.h | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
> index b67a51c..8810f1f 100644
> --- a/include/linux/energy_model.h
> +++ b/include/linux/energy_model.h
> @@ -103,6 +103,9 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
>  	struct em_perf_state *ps;
>  	int i, cpu;
>  
> +	if (!sum_util)
> +		return 0;
> +
>  	/*
>  	 * In order to predict the performance state, map the utilization of
>  	 * the most utilized CPU of the performance domain to a requested

Makes sense to me, so with nit above:

Acked-by: Quentin Perret <qperret@google.com>

Thanks!
Quentin