On 16 Dec 2021, at 17:32, Yi Zhang [off-list ref] wrote:

On Thu, Dec 16, 2021 at 9:21 PM Max Gurtovoy [off-list ref] wrote:

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On 12/16/2021 4:18 AM, Yi Zhang wrote:

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On Wed, Dec 15, 2021 at 8:10 PM Max Gurtovoy [off-list ref] wrote:

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On 12/15/2021 3:15 AM, Yi Zhang wrote:

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On Tue, Dec 14, 2021 at 8:01 PM Max Gurtovoy [off-list ref] wrote:

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On 12/14/2021 12:39 PM, Sagi Grimberg wrote:

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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

So it appears that destroying a qp takes a long time on
IB for some reason...

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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...

Max?

It took me 12s to reset a controller with 63 IO queues with 5.16-rc3+.

Can you try repro with latest versions please ?

Or give the exact scenario ?

Yeah, both target and client are using Mellanox Technologies MT27700
Family [ConnectX-4], could you try stress "nvme reset /dev/nvme0", the
first time reset will take 12s, and it always can be reproduced at the
second reset operation.

I created a target with 1 namespace backed by null_blk and connected to
it from the same server in loopback rdma connection using the ConnectX-4
adapter.

Could you share your loop.json file so I can try it on my environment?

{
  "hosts": [],
  "ports": [
    {
      "addr": {
        "adrfam": "ipv4",
        "traddr": "<ip>",
        "treq": "not specified",
        "trsvcid": "4420",
        "trtype": "rdma"
      },
      "portid": 1,
      "referrals": [],
      "subsystems": [
        "testsubsystem_0"
      ]
    }
  ],
  "subsystems": [
    {
      "allowed_hosts": [],
      "attr": {
        "allow_any_host": "1",
        "cntlid_max": "65519",
        "cntlid_min": "1",
        "model": "Linux",
        "serial": "3d83c78b76623f1d",
        "version": "1.3"
      },
      "namespaces": [
        {
          "device": {
            "nguid": "5b722b05-e9b6-542d-ba80-62010b57775d",
            "path": "/dev/nullb0",
            "uuid": "26ffc8ce-73b4-321d-9685-7d7a9872c460"
          },
          "enable": 1,
          "nsid": 1
        }
      ],
      "nqn": "testsubsystem_0"
    }
  ]
}

Thanks, I reproduced it with your json file on one server with
loopback rdma connection:
# time nvme connect -t rdma -a 172.31.0.202 -s 4420 -n testsubsystem_0

real 0m4.557s
user 0m0.000s
sys 0m0.005s
# time nvme reset /dev/nvme0

real 0m13.176s
user 0m0.000s
sys 0m0.007s
# time nvme reset /dev/nvme0

real 1m16.577s
user 0m0.002s
sys 0m0.005s
# time nvme disconnect -n testsubsystem_0

What does:

# rdma res show qp | grep -c ERR

say, when it is slow?



Thxs, Håkon

NQN:testsubsystem_0 disconnected 1 controller(s)

real 1m11.541s
user 0m0.000s
sys 0m0.187s

#dmesg
[96600.362827] nvmet: creating nvm controller 1 for subsystem
testsubsystem_0 for NQN
nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4d10-8030-b7c04f393432.
[96600.363038] nvme nvme0: creating 40 I/O queues.
[96604.905514] nvme nvme0: mapped 40/0/0 default/read/poll queues.
[96604.909161] nvme nvme0: new ctrl: NQN "testsubsystem_0", addr
172.31.0.202:4420
[96614.270825] nvme nvme0: Removing ctrl: NQN "testsubsystem_0"
[96659.268006] nvmet: creating nvm controller 1 for subsystem
testsubsystem_0 for NQN
nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4d10-8030-b7c04f393432.
[96659.268215] nvme nvme0: creating 40 I/O queues.
[96663.801929] nvme nvme0: mapped 40/0/0 default/read/poll queues.
[96663.805589] nvme nvme0: new ctrl: NQN "testsubsystem_0", addr
172.31.0.202:4420
[96673.130986] nvme nvme0: resetting controller
[96681.761992] nvmet: creating nvm controller 1 for subsystem
testsubsystem_0 for NQN
nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4d10-8030-b7c04f393432.
[96681.762133] nvme nvme0: creating 40 I/O queues.
[96686.302544] nvme nvme0: mapped 40/0/0 default/read/poll queues.
[96688.850272] nvme nvme0: resetting controller
[96697.336217] nvmet: ctrl 1 keep-alive timer (5 seconds) expired!
[96697.361231] nvmet: ctrl 1 fatal error occurred!
[96760.824363] nvme nvme0: I/O 25 QID 0 timeout
[96760.847531] nvme nvme0: Property Set error: 881, offset 0x14
[96760.885731] nvmet: creating nvm controller 1 for subsystem
testsubsystem_0 for NQN
nqn.2014-08.org.nvmexpress:uuid:4c4c4544-0056-4d10-8030-b7c04f393432.
[96760.885879] nvme nvme0: creating 40 I/O queues.
[96765.423099] nvme nvme0: mapped 40/0/0 default/read/poll queues.
[96808.112730] nvme nvme0: Removing ctrl: NQN "testsubsystem_0"
[96816.632485] nvmet: ctrl 1 keep-alive timer (5 seconds) expired!
[96816.657537] nvmet: ctrl 1 fatal error occurred!
[96879.608632] nvme nvme0: I/O 12 QID 0 timeout
[96879.632104] nvme nvme0: Property Set error: 881, offset 0x14>

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And can you try it with two servers that both have CX-4? This should
be easier to reproduce it.

I did this experiment. I have only a setup with 12 cores so I created 12
nvmf queues.

The reset took 4 seconds. The test did 100 loops of "nvme reset".

I saw that you also complained on the disconnect flow so I assume the
root cause is the same.

Yeah, I think so

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My disconnect took 2 seconds.

My FW version is 12.28.2006.

Yeah, mine is same with yours.
# cat /sys/devices/pci0000\:00/0000\:00\:02.0/0000\:04\:00.0/infiniband/mlx5_0/fw_ver
12.28.2006

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I run a loop with the "nvme reset" command and it took me 4-5 secs to
reset each time..

-- 
Best Regards,
 Yi Zhang