diff options
Diffstat (limited to 'include/net/net_namespace.h')
| -rw-r--r-- | include/net/net_namespace.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index d4417495773a..71abc8d79178 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -312,6 +312,20 @@ struct net *get_net_ns_by_id(struct net *net, int id); struct pernet_operations { struct list_head list; + /* + * Below methods are called without any exclusive locks. + * More than one net may be constructed and destructed + * in parallel on several cpus. Every pernet_operations + * have to keep in mind all other pernet_operations and + * to introduce a locking, if they share common resources. + * + * Exit methods using blocking RCU primitives, such as + * synchronize_rcu(), should be implemented via exit_batch. + * Then, destruction of a group of net requires single + * synchronize_rcu() related to these pernet_operations, + * instead of separate synchronize_rcu() for every net. + * Please, avoid synchronize_rcu() at all, where it's possible. + */ int (*init)(struct net *net); void (*exit)(struct net *net); void (*exit_batch)(struct list_head *net_exit_list); |