On 01/30/2018 07:32 PM, Cong Wang wrote: > On Tue, Jan 30, 2018 at 4:09 AM, Dmitry Vyukov <dvyu...@google.com> wrote: >> Hello, >> >> The following program creates a hang in unregister_netdevice. >> cleanup_net work hangs there forever periodically printing >> "unregister_netdevice: waiting for lo to become free. Usage count = 3" >> and creation of any new network namespaces hangs forever. > > Interestingly, this is not reproducible on net-next.
The most recent change on netns refcnt was 4ee806d51176 ("net: tcp: close sock if net namespace is exiting") in net/net-next from 5 days ago, maybe fixed due to that?