| Message ID | 1477017986-18889-1-git-send-email-avagin@openvz.org |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Oct 20, 2016 at 7:46 PM, Andrei Vagin <avagin@openvz.org> wrote: > No one can see these events, because a network namespace can not be > destroyed, if it has sockets. > Are you sure? kobject_uevent_env() seems sending uevents to all network namespaces.
On Thu, Oct 20, 2016 at 8:10 PM, Cong Wang <xiyou.wangcong@gmail.com> wrote: > On Thu, Oct 20, 2016 at 7:46 PM, Andrei Vagin <avagin@openvz.org> wrote: >> No one can see these events, because a network namespace can not be >> destroyed, if it has sockets. >> > > Are you sure? kobject_uevent_env() seems sending uevents to all > network namespaces. kobj_bcast_filter() checks that a kobject namespace is equal to a socket namespace. > _______________________________________________ > Containers mailing list > Containers@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/containers
Hi Cong, On Thu, Oct 20, 2016 at 10:25 PM, Andrey Vagin <avagin@openvz.org> wrote: > On Thu, Oct 20, 2016 at 8:10 PM, Cong Wang <xiyou.wangcong@gmail.com> wrote: >> On Thu, Oct 20, 2016 at 7:46 PM, Andrei Vagin <avagin@openvz.org> wrote: >>> No one can see these events, because a network namespace can not be >>> destroyed, if it has sockets. >>> >> >> Are you sure? kobject_uevent_env() seems sending uevents to all >> network namespaces. > > kobj_bcast_filter() checks that a kobject namespace is equal to a > socket namespace. Today I've checked that it really works as I read from the source code. I use this tool to read events: https://gist.github.com/avagin/430ba431fc2972002df40ebe6a048b36 And I see that events from non-network devices are delivered to all sockets, but events from network devices are delivered only to sockets from a network namespace where a device is operated. Thanks, Andrei > > >> _______________________________________________ >> Containers mailing list >> Containers@lists.linux-foundation.org >> https://lists.linuxfoundation.org/mailman/listinfo/containers
From: Andrei Vagin <avagin@openvz.org> Date: Thu, 20 Oct 2016 19:46:26 -0700 > @@ -1525,6 +1530,9 @@ void netdev_unregister_kobject(struct net_device *ndev) > { > struct device *dev = &(ndev->dev); > > + if (!list_empty(&dev_net(ndev)->exit_list)) > + dev->kobj.uevent_suppress = 1; > + Please use "dev_set_uevent_suppress(dev, 1);"
On Sat, Oct 22, 2016 at 12:37 AM, Andrey Vagin <avagin@openvz.org> wrote: > Hi Cong, > > On Thu, Oct 20, 2016 at 10:25 PM, Andrey Vagin <avagin@openvz.org> wrote: >> On Thu, Oct 20, 2016 at 8:10 PM, Cong Wang <xiyou.wangcong@gmail.com> wrote: >>> On Thu, Oct 20, 2016 at 7:46 PM, Andrei Vagin <avagin@openvz.org> wrote: >>>> No one can see these events, because a network namespace can not be >>>> destroyed, if it has sockets. >>>> >>> >>> Are you sure? kobject_uevent_env() seems sending uevents to all >>> network namespaces. >> >> kobj_bcast_filter() checks that a kobject namespace is equal to a >> socket namespace. > > Today I've checked that it really works as I read from the source code. > I use this tool to read events: > https://gist.github.com/avagin/430ba431fc2972002df40ebe6a048b36 > > And I see that events from non-network devices are delivered to all sockets, > but events from network devices are delivered only to sockets from > a network namespace where a device is operated. I missed it, it makes sense now. Please consider adding a comment in the code or expanding your changelog for reference. Thanks!
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 6e4f347..c02515e 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -950,10 +950,13 @@ net_rx_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) } while (--i >= new_num) { + struct kobject *kobj = &dev->_rx[i].kobj; + + if (!list_empty(&dev_net(dev)->exit_list)) + kobj->uevent_suppress = 1; if (dev->sysfs_rx_queue_group) - sysfs_remove_group(&dev->_rx[i].kobj, - dev->sysfs_rx_queue_group); - kobject_put(&dev->_rx[i].kobj); + sysfs_remove_group(kobj, dev->sysfs_rx_queue_group); + kobject_put(kobj); } return error; @@ -1340,6 +1343,8 @@ netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) while (--i >= new_num) { struct netdev_queue *queue = dev->_tx + i; + if (!list_empty(&dev_net(dev)->exit_list)) + queue->kobj.uevent_suppress = 1; #ifdef CONFIG_BQL sysfs_remove_group(&queue->kobj, &dql_group); #endif @@ -1525,6 +1530,9 @@ void netdev_unregister_kobject(struct net_device *ndev) { struct device *dev = &(ndev->dev); + if (!list_empty(&dev_net(ndev)->exit_list)) + dev->kobj.uevent_suppress = 1; + kobject_get(&dev->kobj); remove_queue_kobjects(ndev);
No one can see these events, because a network namespace can not be destroyed, if it has sockets. My experiments shows that net namespaces are destroyed more 30% faster with this optimization. Here is a perf output for destroying network namespaces without this patch. - 94.76% 0.02% kworker/u48:1 [kernel.kallsyms] [k] cleanup_net - 94.74% cleanup_net - 94.64% ops_exit_list.isra.4 - 41.61% default_device_exit_batch - 41.47% unregister_netdevice_many - rollback_registered_many - 40.36% netdev_unregister_kobject - 14.55% device_del + 13.71% kobject_uevent - 13.04% netdev_queue_update_kobjects + 12.96% kobject_put - 12.72% net_rx_queue_update_kobjects kobject_put - kobject_release + 12.69% kobject_uevent + 0.80% call_netdevice_notifiers_info + 19.57% nfsd_exit_net + 11.15% tcp_net_metrics_exit + 8.25% rpcsec_gss_exit_net It's very critical to optimize the exit path for network namespaces, because they are destroyed under net_mutex and many namespaces can be destroyed for one iteration. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrei Vagin <avagin@openvz.org> --- net/core/net-sysfs.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)