On 3/2/16 10:01 AM, Andrey Wagin wrote:
Hi David,We execute CRIU test on linux-next. On the current linux-next kernel they hangs on creating a network namespace. The kernel log contains many massages like this: [ 1036.122108] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 1046.165156] unregister_netdevice: waiting for lo to become free. Usage count = 2 [ 1056.210287] unregister_netdevice: waiting for lo to become free. Usage count = 2 I tried to revert this patch and the bug disappeared. Here is a set of commands to reproduce this bug: [root@linux-next-test linux-next]# uname -a Linux linux-next-test 4.5.0-rc6-next-20160301+ #3 SMP Wed Mar 2 17:32:18 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux [root@linux-next-test ~]# unshare -n [root@linux-next-test ~]# ip link set up dev lo [root@linux-next-test ~]# ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever [root@linux-next-test ~]# logout [root@linux-next-test ~]# unshare -n
Thanks for reporting -- with reproduction commands. I will post patch as soon as I have time to look into it.
David
