Re: [PATCH v7 3/6] cpufreq: powernv: Remove cpu_to_chip_id() from hot-path

From: Gautham R Shenoy
Date: Thu Jan 28 2016 - 03:11:21 EST


On Thu, Jan 28, 2016 at 12:55:38PM +0530, Shilpasri G Bhat wrote:
> cpu_to_chip_id() does a DT walk through to find out the chip id by
> taking a contended device tree lock. This adds an unnecessary overhead
> in a hot path. So instead of calling cpu_to_chip_id() everytime cache
> the chip ids for all cores in the array 'core_to_chip_map' and use it
> in the hotpath.
>
> Reported-by: Anton Blanchard <anton@xxxxxxxxx>
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>

Reviewed-by: Gautham R. Shenoy <ego@xxxxxxxxxxxxxxxxxx>

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Thanks and Regards
gautham.