Re: [PATCH V5 1/2] ufs: core: Add CPU latency QoS support for ufs driver

From: Peter Wang (王信友)
Date: Fri Dec 15 2023 - 01:59:15 EST


On Wed, 2023-12-13 at 18:13 +0530, Maramaina Naresh wrote:
>
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> Register ufs driver to CPU latency PM QoS framework to improve
> ufs device random io performance.
>
> PM QoS initialization will insert new QoS request into the CPU
> latency QoS list with the maximum latency PM_QOS_DEFAULT_VALUE
> value.
>
> UFS driver will vote for performance mode on scale up and power
> save mode for scale down.
>
> If clock scaling feature is not enabled then voting will be based
> on clock on or off condition.
>
> Provided sysfs interface to enable/disable PM QoS feature.
>
> tiotest benchmark tool io performance results on sm8550 platform:
>
> 1. Without PM QoS support
> Type (Speed in) | Average of 18 iterations
> Random Write(IPOS) | 41065.13
> Random Read(IPOS) | 37101.3
>
> 2. With PM QoS support
> Type (Speed in) | Average of 18 iterations
> Random Write(IPOS) | 46784.9
> Random Read(IPOS) | 42943.4
> (Improvement with PM QoS = ~15%).
>

Reviewed-by: Peter Wang <peter.wang@xxxxxxxxxxxx>