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Date:   Thu, 25 Apr 2019 11:57:00 +0100
From:   Quentin Perret <quentin.perret@arm.com>
To:     Thara Gopinath <thara.gopinath@linaro.org>
Cc:     mingo@redhat.com, peterz@infradead.org, rui.zhang@intel.com,
        linux-kernel@vger.kernel.org, amit.kachhap@gmail.com,
        viresh.kumar@linaro.org, javi.merino@kernel.org,
        edubezval@gmail.com, daniel.lezcano@linaro.org,
        vincent.guittot@linaro.org, nicolas.dechesne@linaro.org,
        bjorn.andersson@linaro.org, dietmar.eggemann@arm.com
Subject: Re: [PATCH V2 1/3] Calculate Thermal Pressure
Message-ID: <20190425105658.q45cmfogrt6wwtih@queper01-ThinkPad-T460s>
References: <1555443521-579-1-git-send-email-thara.gopinath@linaro.org>
 <1555443521-579-2-git-send-email-thara.gopinath@linaro.org>
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On Tuesday 16 Apr 2019 at 15:38:39 (-0400), Thara Gopinath wrote:
> +/* Per cpu structure to keep track of Thermal Pressure */
> +struct thermal_pressure {
> +	unsigned long scale; /* scale reflecting average cpu max capacity*/
> +	unsigned long acc_scale; /* Accumulated scale for this time window */
> +	unsigned long old_scale; /* Scale value for the previous window */
> +	unsigned long raw_scale; /* Raw max capacity */
> +	unsigned long age_stamp; /* Last time old_scale was updated */
> +	unsigned long last_update; /* Last time acc_scale was updated */
> +	spinlock_t lock; /* Lock for protecting from simultaneous access*/
> +	/* Timer for periodic update of thermal pressure */
> +	struct timer_list timer;

Do you actually need the periodic update ? You only really need to
update the 'scale' value when updating the LB stats no ? Nobody
accesses that value in between two LBs.

Thanks,
Quentin