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authorAndrey Vagin <avagin@openvz.org>2016-10-25 05:09:53 +0300
committerDavid S. Miller <davem@davemloft.net>2016-10-28 00:14:47 +0300
commit002d8a1a6c11b9b2a8ac615095589111dd52749b (patch)
treee997be9ecb7d7b15297522c905b6392d3932a3b7 /net
parent110447f8269a608cd69203fa2ccd801ea92e0a1a (diff)
downloadlinux-002d8a1a6c11b9b2a8ac615095589111dd52749b.tar.xz
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')
-rw-r--r--net/core/net-sysfs.c14
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);