Re: [LKP] [lkp] [net] 21bb45b419: kmsg.unregister_netdevice:waiting_for_br-lan_to_become_free.Usage_count=

From: "Huang\, Ying" <ying.huang@intel.com>
To: David Ahern <dsa@cumulusnetworks.com>
Cc: 0day robot <fengguang.wu@intel.com>, <lkp@01.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [LKP] [lkp] [net] 21bb45b419: kmsg.unregister_netdevice:waiting_for_br-lan_to_become_free.Usage_count=
Date: Wed, 02 Mar 2016 16:00:58 +0800	[thread overview]
Message-ID: <87y4a1pav9.fsf@yhuang-dev.intel.com> (raw)
In-Reply-To: <56D49603.4010900@cumulusnetworks.com> (David Ahern's message of "Mon, 29 Feb 2016 11:03:31 -0800")

David Ahern <dsa@cumulusnetworks.com> writes:

> On 2/29/16 12:50 AM, kernel test robot wrote:
>> FYI, we noticed the below changes on
>>
>> https://github.com/0day-ci/linux  David-Ahern/net-ipv6-Make-address-flushing-on-ifdown-optional/20160214-062626
>> commit 21bb45b419243ee4d9d74f1d1f97164fbfc481c3 ("net: ipv6: Make address flushing on ifdown optional")
>>
>>
>> [  136.160531] unregister_netdevice: waiting for br-lan to become free. Usage count = 1
>>
>
> How do I get the series of commands run? From the logs it looks like
> there is a creation of a bridge, eth0 enslavement, admin down on
> bridge and then delete of the bridge. When I run those commands in a
> VM I do not hit the usage count of 1, so I am clearly missing some
> commands.

The command line to run qemu is as follow:

qemu-system-x86_64 -enable-kvm -kernel /pkg/linux/x86_64-randconfig-n0-02271436/gcc-5/21bb45b419243ee4d9d74f1d1f97164fbfc481c3/vmlinuz-4.5.0-rc2-00420-g21bb45b -append 'root=/dev/ram0 user=lkp job=/lkp/scheduled/vm-client3-openwrt-ia32-2/rand_boot-1-openwrt-i386.cgz-x86_64-randconfig-n0-02271436-21bb45b419243ee4d9d74f1d1f97164fbfc481c3-20160228-50262-1pt11n1-0.yaml ARCH=x86_64 kconfig=x86_64-randconfig-n0-02271436 branch=linux-devel/devel-hourly-2016022600 commit=21bb45b419243ee4d9d74f1d1f97164fbfc481c3 BOOT_IMAGE=/pkg/linux/x86_64-randconfig-n0-02271436/gcc-5/21bb45b419243ee4d9d74f1d1f97164fbfc481c3/vmlinuz-4.5.0-rc2-00420-g21bb45b max_uptime=600 RESULT_ROOT=/result/boot/1/vm-client3-openwrt-ia32/openwrt-i386.cgz/x86_64-randconfig-n0-02271436/gcc-5/21bb45b419243ee4d9d74f1d1f97164fbfc481c3/0 LKP_SERVER=inn earlyprintk=ttyS0,115200 systemd.log_level=err debug apic=debug sysrq_always_enabled rcupdate.rcu_cpu_stall_timeout=100 panic=-1 softlockup_panic=1 nmi_watchdog=panic oops=panic load_ramdisk=2 prompt_ramdisk=0 console=ttyS0,115200 console=tty0 vga=normal rw ip=::::vm-client3-openwrt-ia32-2::dhcp drbd.minor_count=8'  -initrd /fs/sdb6/initrd-vm-client3-openwrt-ia32-2 -m 192 -smp 1 -device e1000,netdev=net0 -netdev user,id=net0 -boot order=nc -no-reboot -watchdog i6300esb -rtc base=localtime -drive file=/fs/sdb6/disk0-vm-client3-openwrt-ia32-2,media=disk,if=virtio -drive file=/fs/sdb6/disk1-vm-client3-openwrt-ia32-2,media=disk,if=virtio -pidfile /dev/shm/kboot/pid-vm-client3-openwrt-ia32-2 -serial file:/dev/shm/kboot/serial-vm-client3-openwrt-ia32-2 -daemonize -display none -monitor null

The root file system used for test can be downloaded in:

https://github.com/fengguang/reproduce-kernel-bug/tree/master/initrd

The one used for test should be yocto i386 root image.

Best Regards,
Huang, Ying

> Thanks for the report,
> David
> _______________________________________________
> LKP mailing list
> LKP@lists.01.org
> https://lists.01.org/mailman/listinfo/lkp