Julian Anastasov <j...@ssi.bg> writes: > Hello, > > On Mon, 28 Sep 2015, Anand Gurram wrote: > >> I am currently using kernel version 3.16.7 on a linux switch. >> While creating and destroying network namespaces I am observing below logs >> on the console >> "unregister_netdevice: waiting for lo to become free. Usage count = 1" >> >> Can you please suggest and provide instructions on how to debug this issue. >> If any fix already available can you please point me to the link. > > There are two commits from Linux 4.2 that may help: > > commit e9e4dd3267d0 ("net: do not process device backlog during > unregistration") > commit 2c17d27c36dc ("net: call rcu_read_lock early in process_backlog") > > For now I see them only in 3.2.71+ and 3.12.48+. > I think, they will appear in other stable versions too...
If that message repeats indefinitely it means there is a leaked reference to the network namespaces lo device. If the message just spits out a few times and then goes away it simply means that something is taking a while to cleanup and drop it's reference. This is slightly complicated by the fact that it is not uncommon when a network device goes away to redirect all references to itself to the lo device. Eric -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html