Hi David, On Tue, Mar 01, 2016 at 12:07:49PM -0800, Jeremiah Mahler wrote: > Hi all, > > On Tue, Mar 01, 2016 at 08:11:54AM +0000, Dexuan Cui wrote: > > Hi, I got this line every 10 seconds with today's linux-next in a Hyper-V > > guest, even > > when I didn't configure any NIC for the guest: > > > > [ 72.604249] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > [ 82.708170] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > [ 92.788079] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > [ 102.808132] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > [ 112.928166] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > [ 122.952069] unregister_netdevice: waiting for lo to become free. Usage > > count = 2 > > > > I don't think this is related to the underlying host, since it's related to > > "lo". > > > > This should be a recent regression, as I remember the January linux-next > > didn't have > > this issue. > > > > Any idea? > > > > The gzip-ed kernel config is attached FYI. > > > > Thanks, > > -- Dexuan > > > > Just a "me too", but I have this problem on a Lenovo Carbon X1 when > running linux-next 20160301. It worked with 20160225. > > I can test patches and I will try to bisect the problem as time allows. > > -- > - Jeremiah Mahler
I performed a bisect and found that the following patch introduced the regression. From f1705ec197e705b79ea40fe7a2cc5acfa1d3bfac Mon Sep 17 00:00:00 2001 From: David Ahern <[email protected]> Date: Wed, 24 Feb 2016 09:25:37 -0800 Subject: [PATCH] net: ipv6: Make address flushing on ifdown optional Currently, all ipv6 addresses are flushed when the interface is configured down, including global, static addresses: $ ip -6 addr show dev eth1 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000 inet6 2100:1::2/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe79:34bd/64 scope link valid_lft forever preferred_lft forever $ ip link set dev eth1 down $ ip -6 addr show dev eth1 << nothing; all addresses have been flushed>> Add a new sysctl to make this behavior optional. The new setting defaults to flush all addresses to maintain backwards compatibility. When the set global addresses with no expire times are not flushed on an admin down. The sysctl is per-interface or system-wide for all interfaces $ sysctl -w net.ipv6.conf.eth1.keep_addr_on_down=1 or $ sysctl -w net.ipv6.conf.all.keep_addr_on_down=1 Will keep addresses on eth1 on an admin down. $ ip -6 addr show dev eth1 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000 inet6 2100:1::2/120 scope global valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe79:34bd/64 scope link valid_lft forever preferred_lft forever $ ip link set dev eth1 down $ ip -6 addr show dev eth1 3: eth1: <BROADCAST,MULTICAST> mtu 1500 state DOWN qlen 1000 inet6 2100:1::2/120 scope global tentative valid_lft forever preferred_lft forever inet6 fe80::e0:f9ff:fe79:34bd/64 scope link tentative valid_lft forever preferred_lft forever Signed-off-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]> --- Documentation/networking/ip-sysctl.txt | 9 +++ include/linux/ipv6.h | 1 + include/uapi/linux/ipv6.h | 1 + net/ipv6/addrconf.c | 136 +++++++++++++++++++++++++++++---- 4 files changed, 132 insertions(+), 15 deletions(-) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 24ce97f..d5df40c 100644 [...] -- 2.7.0 -- - Jeremiah Mahler
