Re: [bug report] block: Non-NCQ commands will never be executed while fio is continuously running

[yangxingui]

On 2024/9/9 21:21, Damien Le Moal wrote:
> On 9/9/24 22:10, yangxingui wrote:
> > Hello axboe & John,
> >
> > After the driver exposes all HW queues to the block layer, non-NCQ
> > commands will never be executed while fio is continuously running, such
> > as a smartctl command.
> >
> > The cause of the problem is that other hctx used by the NCQ command is
> > still active and can continue to issue NCQ commands to the sata disk.
> > And the pio command keeps retrying in its corresponding hctx because
> > qc_defer() always returns true.
> >
> > hctx0: ncq, pio, ncq
> > hctx1：ncq, ncq, ...
> > ...
> > hctxn: ncq, ncq, ...
> >
> > Is there any good solution for this?
>
> SATA devices are single queue so how can you have multiple queues ?
> What adapter are you using ?

In the following patch, we expose the host's 16 hardware queues to the 
block layer. And when connecting to a sata disk, 16 hctx are used.

8d98416a55eb ("scsi: hisi_sas: Switch v3 hw to MQ")

Thanks,
Xingui
.