Re: [PATCH v2 net-next 0/7] net: speedup netns create/delete time

[Eric Dumazet <edumazet@google.com>]

On Tue, Sep 26, 2017 at 4:21 AM, Tariq Toukan <tariqt@mellanox.com> wrote:
>
>
> Hi Eric,
>
> We see a regression introduced in this series, specifically in the patches
> touching lib/kobject_uevent.c.
> We tried to figure out what is wrong there, but couldn't point it out.
>
> Bug is that mlx4 driver restart fails, because mlx4_core is still in use.
> According to module dependencies, both mlx4_en and mlx4_ib should have been
> unloaded at this point
> Please see log below.
>
> This looks to be some kind of a race, as the repro is not deterministic.
> Probably the en/ib modules are now mistakenly reloaded.
>
> Any idea what could this be?
>
> Regards,
> Tariq
>
>
> [root@reg-l-vrt-41016-009 ~]# /etc/init.d/openibd stop
> Unloading HCA driver:                                      [  OK  ]
> [root@reg-l-vrt-41016-009 ~]# /etc/init.d/openibd start
> Loading HCA driver and Access Layer:                       [  OK  ]
> [root@reg-l-vrt-41016-009 ~]# /etc/init.d/openibd stop
> Unloading mlx4_core                                        [FAILED]
> rmmod: ERROR: Module mlx4_core is in use

I have absolutely no idea. Please bisect.

Are you really using netns in the first place ?