Re: [PATCH v2 19/20] scsi: ufs: Implement polling support

Bart Van Assche
2021-11-30T17:34:25Z

On 11/30/21 7:40 AM, Bean Huo wrote:
> It is the test case in your commit message. If iodepth=1, there is no
> performance improvement. Increase the io-depth to multiple, for
> example, let iodepth= CPU core counter. I see that the interrupt
> overhead is significantly increased when the request is completed, so
> IO_polling will win compared to the interrupt mode.

Hi Bean,

It is not guaranteed that polling will result in a significant performance
improvement. I assume that on my test setup the improvement is so
significant because the interrupt coalescing delay. Maybe the interrupt
coalescing delay is much smaller on your test setup.

Bart.