[bug report] NVMe/IB: reset_controller need more than 1min

[Yi Zhang]

On Thu, Jun 24, 2021 at 5:32 AM Sagi Grimberg <sagi at grimberg.me> wrote:
>
>
> > Hello
> >
> > Gentle ping here, this issue still exists on latest 5.13-rc7
> >
> > # time nvme reset /dev/nvme0
> >
> > real 0m12.636s
> > user 0m0.002s
> > sys 0m0.005s
> > # time nvme reset /dev/nvme0
> >
> > real 0m12.641s
> > user 0m0.000s
> > sys 0m0.007s
>
> Strange that even normal resets take so long...
> What device are you using?

Hi Sagi

Here is the device info:
Mellanox Technologies MT27700 Family [ConnectX-4]

>
> > # time nvme reset /dev/nvme0
> >
> > real 1m16.133s
> > user 0m0.000s
> > sys 0m0.007s
>
> There seems to be a spurious command timeout here, but maybe this
> is due to the fact that the queues take so long to connect and
> the target expires the keep-alive timer.
>
> Does this patch help?

The issue still exists, let me know if you need more testing for it. :)


> --
> diff --git a/drivers/nvme/target/fabrics-cmd.c
> b/drivers/nvme/target/fabrics-cmd.c
> index 7d0f3523fdab..f4a7db1ab3e5 100644
> --- a/drivers/nvme/target/fabrics-cmd.c
> +++ b/drivers/nvme/target/fabrics-cmd.c
> @@ -142,6 +142,14 @@ static u16 nvmet_install_queue(struct nvmet_ctrl
> *ctrl, struct nvmet_req *req)
>                  }
>          }
>
> +       /*
> +        * Controller establishment flow may take some time, and the
> host may not
> +        * send us keep-alive during this period, hence reset the
> +        * traffic based keep-alive timer so we don't trigger a
> +        * controller teardown as a result of a keep-alive expiration.
> +        */
> +       ctrl->reset_tbkas = true;
> +
>          return 0;
>
>   err:
> --
>
> >> target:
> >> [  934.306016] nvmet: creating controller 1 for subsystem testnqn for
> >> NQN nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4c10-8058-b7c04f383432.
> >> [  944.875021] nvmet: ctrl 1 keep-alive timer (5 seconds) expired!
> >> [  944.900051] nvmet: ctrl 1 fatal error occurred!
> >> [ 1005.628340] nvmet: creating controller 1 for subsystem testnqn for
> >> NQN nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4c10-8058-b7c04f383432.
> >>
> >> client:
> >> [  857.264029] nvme nvme0: resetting controller
> >> [  864.115369] nvme nvme0: creating 40 I/O queues.
> >> [  867.996746] nvme nvme0: mapped 40/0/0 default/read/poll queues.
> >> [  868.001673] nvme nvme0: resetting controller
> >> [  935.396789] nvme nvme0: I/O 9 QID 0 timeout
> >> [  935.402036] nvme nvme0: Property Set error: 881, offset 0x14
> >> [  935.438080] nvme nvme0: creating 40 I/O queues.
> >> [  939.332125] nvme nvme0: mapped 40/0/0 default/read/poll queues.
>


-- 
Best Regards,
  Yi Zhang