On Mon, Dec 13, 2021 at 5:05 PM Sagi Grimberg [off-list ref] wrote:

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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]

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# 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. :)

Hi Sagi
ping, this issue still can be reproduced on the latest
linux-block/for-next, do you have a chance to recheck it, thanks.

Can you check if it happens with the below patch:

Hi Sagi
It is still reproducible with the change, here is the log:

# time nvme reset /dev/nvme0

real    0m12.973s
user    0m0.000s
sys     0m0.006s
# time nvme reset /dev/nvme0

real    1m15.606s
user    0m0.000s
sys     0m0.007s

Does it speed up if you use less queues? (i.e. connect with -i 4) ?

Yes, with -i 4, it has stablee 1.3s
# time nvme reset /dev/nvme0

real 0m1.225s
user 0m0.000s
sys 0m0.007s

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# dmesg | grep nvme
[  900.634877] nvme nvme0: resetting controller
[  909.026958] nvme nvme0: creating 40 I/O queues.
[  913.604297] nvme nvme0: mapped 40/0/0 default/read/poll queues.
[  917.600993] nvme nvme0: resetting controller
[  988.562230] nvme nvme0: I/O 2 QID 0 timeout
[  988.567607] nvme nvme0: Property Set error: 881, offset 0x14
[  988.608181] nvme nvme0: creating 40 I/O queues.
[  993.203495] nvme nvme0: mapped 40/0/0 default/read/poll queues.

BTW, this issue cannot be reproduced on my NVME/ROCE environment.

Then I think that we need the rdma folks to help here...

-- 
Best Regards,
  Yi Zhang