net: Batch inet_twsk_purge
This function walks the whole hashtable so there is no point in
passing it a network namespace. Instead I purge all timewait
sockets from dead network namespaces that I find. If the namespace
is one of the once I am trying to purge I am guaranteed no new timewait
sockets can be formed so this will get them all. If the namespace
is one I am not acting for it might form a few more but I will
call inet_twsk_purge again and shortly to get rid of them. In
any even if the network namespace is dead timewait sockets are
useless.
Move the calls of inet_twsk_purge into batch_exit routines so
that if I am killing a bunch of namespaces at once I will just
call inet_twsk_purge once and save a lot of redundant unnecessary
work.
My simple 4k network namespace exit test the cleanup time dropped from
roughly 8.2s to 1.6s. While the time spent running inet_twsk_purge fell
to about 2ms. 1ms for ipv4 and 1ms for ipv6.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 773b10f..4fd007f3 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -212,14 +212,14 @@
extern void inet_twsk_deschedule(struct inet_timewait_sock *tw,
struct inet_timewait_death_row *twdr);
-extern void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo,
+extern void inet_twsk_purge(struct inet_hashinfo *hashinfo,
struct inet_timewait_death_row *twdr, int family);
static inline
struct net *twsk_net(const struct inet_timewait_sock *twsk)
{
#ifdef CONFIG_NET_NS
- return twsk->tw_net;
+ return rcu_dereference(twsk->tw_net);
#else
return &init_net;
#endif
@@ -229,7 +229,7 @@
void twsk_net_set(struct inet_timewait_sock *twsk, struct net *net)
{
#ifdef CONFIG_NET_NS
- twsk->tw_net = net;
+ rcu_assign_pointer(twsk->tw_net, net);
#endif
}
#endif /* _INET_TIMEWAIT_SOCK_ */