diff options
| author | Andrey Vagin <avagin@openvz.org> | 2016-10-24 19:09:53 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-10-27 17:14:47 -0400 |
| commit | 002d8a1a6c11b9b2a8ac615095589111dd52749b (patch) | |
| tree | e997be9ecb7d7b15297522c905b6392d3932a3b7 /net/core | |
| parent | 110447f8269a608cd69203fa2ccd801ea92e0a1a (diff) | |
net: skip genenerating uevents for network namespaces that are exiting
No one can see these events, because a network namespace can not be
destroyed, if it has sockets.
Unlike other devices, uevent-s for network devices are generated
only inside their network namespaces. They are filtered in
kobj_bcast_filter()
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.
v2: use dev_set_uevent_suppress()
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/net-sysfs.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 6e4f34721080..d4fe28606ff5 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_set_uevent_suppress(dev, 1); + kobject_get(&dev->kobj); remove_queue_kobjects(ndev); |