Commit b099ce26 authored by Eric W. Biederman's avatar Eric W. Biederman Committed by David S. Miller
Browse files

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: default avatarEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 575f4cd5

include/net/inet_timewait_sock.h

+3 −3
Original line number Diff line number Diff line
@@ -212,14 +212,14 @@ extern void inet_twsk_schedule(struct inet_timewait_sock *tw, 
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 @@ static inline 
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_ */

net/ipv4/inet_timewait_sock.c

+5 −5
Original line number Diff line number Diff line
@@ -421,7 +421,7 @@ out: 


EXPORT_SYMBOL_GPL(inet_twdr_twcal_tick);



void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo,

void inet_twsk_purge(struct inet_hashinfo *hashinfo,

		     struct inet_timewait_death_row *twdr, int family)

{

	struct inet_timewait_sock *tw;
@@ -436,15 +436,15 @@ restart_rcu: 
restart:

		sk_nulls_for_each_rcu(sk, node, &head->twchain) {

			tw = inet_twsk(sk);

			if (!net_eq(twsk_net(tw), net) ||

			    tw->tw_family != family)

			if ((tw->tw_family != family) ||

				atomic_read(&twsk_net(tw)->count))

				continue;



			if (unlikely(!atomic_inc_not_zero(&tw->tw_refcnt)))

				continue;



			if (unlikely(!net_eq(twsk_net(tw), net) ||

				     tw->tw_family != family)) {

			if (unlikely((tw->tw_family != family) ||

				     atomic_read(&twsk_net(tw)->count))) {

				inet_twsk_put(tw);

				goto restart;

			}

net/ipv4/tcp_ipv4.c

+8 −3
Original line number Diff line number Diff line
@@ -2529,12 +2529,17 @@ static int __net_init tcp_sk_init(struct net *net) 
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,

       .exit_batch = tcp_sk_exit_batch,

};



void __init tcp_v4_init(void)

net/ipv6/tcp_ipv6.c

+8 −3
Original line number Diff line number Diff line
@@ -2184,12 +2184,17 @@ static int tcpv6_net_init(struct net *net) 
static void tcpv6_net_exit(struct net *net)

{

	inet_ctl_sock_destroy(net->ipv6.tcp_sk);

	inet_twsk_purge(net, &tcp_hashinfo, &tcp_death_row, AF_INET6);

}



static void tcpv6_net_exit_batch(struct list_head *net_exit_list)

{

	inet_twsk_purge(&tcp_hashinfo, &tcp_death_row, AF_INET6);

}



static struct pernet_operations tcpv6_net_ops = {

	.init	    = tcpv6_net_init,

	.exit	    = tcpv6_net_exit,

	.exit_batch = tcpv6_net_exit_batch,

};



int __init tcpv6_init(void)

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