Re: [PATCH 00/26] Zone write plugging

Bart Van Assche
2024-02-05T18:18:48Z

On 2/1/24 23:30, Damien Le Moal wrote:
> - Zone write plugging operates on BIOs instead of requests. Plugged
> BIOs waiting for execution thus do not hold scheduling tags and thus
> do not prevent other BIOs from being submitted to the device (reads
> or writes to other zones). Depending on the workload, this can
> significantly improve the device use and the performance.

Deep queues may introduce performance problems. In Android we had to
restrict the number of pending writes to the device queue depth because
otherwise read latency is too high (e.g. to start the camera app).

I'm not convinced that queuing zoned write bios is a better approach than
queuing zoned write requests.

Are there numbers available about the performance differences (bandwidth
and latency) between plugging zoned write bios and zoned write plugging
requests?

Thanks,

Bart.