On Tue, Jul 11, 2017 at 11:24:44PM +0200, Roger Pau Monn� wrote:

On Wed, Jul 12, 2017 at 02:20:58AM +0800, Ming Lei wrote:

quoted

This interfaces will be removed soon, so use quiesce and
unquiesce instead, which should be more safe.

The only one usage will be removed in the following
congestion control patches.

Would it be better to simply fix blk_mq_{start/stop}_stopped_hw_queues
rather than introducing a new interface?

No, we do not want to expose start/stop state to drivers any more, which
has caused enough trouble already, so these APIs need to be removed, and
quiesce/unquiesce is preferred way for this purpose, as you can see
the work done by Sagi Grimberg:

        http://marc.info/?t=149927415900006&r=1&w=2


Thanks,
Ming