Re: [PATCH v2 18/20] scsi: ufs: Optimize the command queueing code

Asutosh Das (asd)
2021-11-22T23:02:09Z

On 11/22/2021 10:13 AM, Bart Van Assche wrote:
> On 11/22/21 9:46 AM, Asutosh Das (asd) wrote:
>> On 11/19/2021 11:57 AM, Bart Van Assche wrote:
>>> +    blk_freeze_queue_start(hba->tmf_queue);
>>> +    blk_freeze_queue_start(hba->cmd_queue);
>>> +    shost_for_each_device(sdev, hba->host)
>>> +        blk_freeze_queue_start(sdev->request_queue);
>>
>> This would still issue the requests present in the queue before
>> freezing and that's a concern.
>
> Isn't that exactly what the existing code is doing since the existing
> code waits until both doorbell registers are zero? See also
> ufshcd_wait_for_doorbell_clr().
>
> Thanks,
>
> Bart.
Current code waits for the already issued requests to complete. It
doesn't issue the yet-to-be issued requests. Wouldn't freezing the queue
issue the requests in the context of scaling_{up/down}?
If yes, I don't think the current code is doing that.

-asd

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