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/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 59c911f..fee9aab 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2529,12 +2529,17 @@
static void __net_exit tcp_sk_exit(struct net *net)
{
inet_ctl_sock_destroy(net->ipv4.tcp_sock);
- inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET);
+}
+
+static void __net_exit tcp_sk_exit_batch(struct list_head *net_exit_list)
+{
+ inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET);
}
static struct pernet_operations __net_initdata tcp_sk_ops = {
- .init = tcp_sk_init,
- .exit = tcp_sk_exit,
+ .init = tcp_sk_init,
+ .exit = tcp_sk_exit,
+ .exit_batch = tcp_sk_exit_batch,
};
void __init tcp_v4_init(void)