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In-Reply-To: <27769d34-521c-f0ef-b6c2-6bd452e4f9bf@alu.unizg.hr>
From:   Eric Dumazet <edumazet@google.com>
Date:   Tue, 14 Mar 2023 09:02:56 -0700
Message-ID: <CANn89iKi67YScgt5R0nHNAobjnSubBK6KsR9Ryoqu5ai4Opyrw@mail.gmail.com>
Subject: Re: BUG: selftest/net/tun: Hang in unregister_netdevice
To:     Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc:     netdev@vger.kernel.org, linux-kselftest@vger.kernel.org,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, Shuah Khan <shuah@kernel.org>,
        linux-kernel@vger.kernel.org
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On Tue, Mar 14, 2023 at 9:01=E2=80=AFAM Mirsad Todorovac
<mirsad.todorovac@alu.unizg.hr> wrote:

> After a while, kernel message start looping:
>
>   kernel:unregister_netdevice: waiting for tap0 to become free. Usage cou=
nt =3D 3
>
> Message from syslogd@pc-mtodorov at Mar 14 16:57:15 ...
>   kernel:unregister_netdevice: waiting for tap0 to become free. Usage cou=
nt =3D 3
>
> Message from syslogd@pc-mtodorov at Mar 14 16:57:24 ...
>   kernel:unregister_netdevice: waiting for tap0 to become free. Usage cou=
nt =3D 3
>
> Message from syslogd@pc-mtodorov at Mar 14 16:57:26 ...
>   kernel:unregister_netdevice: waiting for tap0 to become free. Usage cou=
nt =3D 3
>
> This hangs processes until very late stage of shutdown.
>
> I can confirm that CONFIG_DEBUG_{KOBJECT,KOBJECT_RELEASE}=3Dy were the on=
ly changes
> to .config in between builds.
>
> Best regards,
> Mirsad
>

Try adding in your config

CONFIG_NET_DEV_REFCNT_TRACKER=3Dy
CONFIG_NET_NS_REFCNT_TRACKER=3Dy

Thanks.