On Thu, Sep 06, 2018 at 09:28:46AM +0800, jianchao.wang wrote: > Hi Ming > > On 09/06/2018 06:09 AM, Ming Lei wrote: > > nvme_dev_add() still may call freeze & unfreeze queue, so your patch > > can't avoid draining queue completely here. > > Yes, I know this. We still need to freeze queue when update nr_hw_queues. > But we move forward a step at least. :) > We don't need to drain request queue in normal case of nvme_reset_work. It is hard to say who is the normal case. In case of CPU hotplug, it is quite easy to trigger updating nr_hw_queues. > > As for updating nr_hw_queues, we could try some other method on it next. The thing is that draining queue may be inevitable inside reset work function because of updating nr_hw_queues, that means the approach in this patchset is just a partial solution Or it may not make sense to do that because we may never remove the draining queue in the code path of updating nr_hw_queues. Given they belong to same issue, I suggest to solve them all. Thanks, Ming
