From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: [net-next,v7] net: ipv6: Make address flushing on ifdown optional Date: Wed, 2 Mar 2016 10:23:17 -0800 Message-ID: <56D72F95.3030101@gmail.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: Andrey Wagin , netdev@vger.kernel.org Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:35621 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932155AbcCBSXT (ORCPT ); Wed, 2 Mar 2016 13:23:19 -0500 Received: by mail-pf0-f176.google.com with SMTP id w128so93730007pfb.2 for ; Wed, 02 Mar 2016 10:23:19 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: 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: 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