Re: [PATCH RFC] virtio-blk: support per-device queue depth

[Joseph Qi <joseph.qi@linux.alibaba.com>]

Hi Jason,

On 1/18/21 1:25 PM, Jason Wang wrote:
> 
> On 2021/1/18 上午11:58, Joseph Qi wrote:
>> module parameter 'virtblk_queue_depth' was firstly introduced for
>> testing/benchmarking purposes described in commit fc4324b4597c
>> ("virtio-blk: base queue-depth on virtqueue ringsize or module param").
>> Since we have different virtio-blk devices which have different
>> capabilities, it requires that we support per-device queue depth instead
>> of per-module. So defaultly use vq free elements if module parameter
>> 'virtblk_queue_depth' is not set.
> 
> 
> I wonder if it's better to use sysfs instead (or whether it has already had something like this in the blocker layer).
> 
Thanks for quick response.
Do you mean adjust /sys/block/vdX/queue/nr_requests?
But current logic in virtblk_probe() is, virtblk_queue_depth is
used as a saved value for first probed vdev, not purely module
parameter.

Thanks,
Joseph