> On 10/9/19 2:32 AM, Ming Lei wrote: > > @@ -354,7 +354,8 @@ void scsi_device_unbusy(struct scsi_device *sdev, > struct scsi_cmnd *cmd) > > if (starget->can_queue > 0) > > atomic_dec(&starget->target_busy); > > > > - atomic_dec(&sdev->device_busy); > > + if (!blk_queue_nonrot(sdev->request_queue)) > > + atomic_dec(&sdev->device_busy); > > } > > > > Hi Ming, > > Does this patch impact the meaning of the queue_depth sysfs attribute (see > also sdev_store_queue_depth()) and also the queue depth ramp up/down > mechanism (see also scsi_handle_queue_ramp_up())? Have you considered to > enable/disable busy tracking per LUN depending on whether or not sdev- > >queue_depth < shost->can_queue? > > The megaraid and mpt3sas drivers read sdev->device_busy directly. Is the > current version of this patch compatible with these drivers?
We need to know per scsi device outstanding in mpt3sas and megaraid_sas driver. Can we get supporting API from block layer (through SML) ? something similar to "atomic_read(&hctx->nr_active)" which can be derived from sdev->request_queue->hctx ? At least for those driver which is nr_hw_queue = 1, it will be useful and we can avoid sdev->device_busy dependency. Kashyap > > Thanks, > > Bart.
