[NET]: Memory barrier cleanups

I believe all the below memory barriers only matter on SMP so
therefore the smp_* variant of the barrier should be used.

I'm wondering if the barrier in net/ipv4/inet_timewait_sock.c should be
dropped entirely.  schedule_work's implementation currently implies a
memory barrier and I think sane semantics of schedule_work() should imply
a memory barrier, as needed so the caller shouldn't have to worry.
It's not quite obvious why the barrier in net/packet/af_packet.c is
needed; maybe it should be implied through flush_dcache_page?

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ralf Baechle 2006-12-07 00:11:33 -08:00 committed by David S. Miller
parent 26db167702
commit e16aa207cc
4 changed files with 6 additions and 6 deletions

View File

@ -2130,7 +2130,7 @@ int iw_handler_set_spy(struct net_device * dev,
* The rtnl_lock() make sure we don't race with the other iw_handlers.
* This make sure wireless_spy_update() "see" that the spy list
* is temporarily disabled. */
wmb();
smp_wmb();
/* Are there are addresses to copy? */
if(wrqu->data.length > 0) {
@ -2159,7 +2159,7 @@ int iw_handler_set_spy(struct net_device * dev,
}
/* Make sure above is updated before re-enabling */
wmb();
smp_wmb();
/* Enable addresses */
spydata->spy_number = wrqu->data.length;

View File

@ -178,7 +178,7 @@ void inet_twdr_hangman(unsigned long data)
need_timer = 0;
if (inet_twdr_do_twkill_work(twdr, twdr->slot)) {
twdr->thread_slots |= (1 << twdr->slot);
mb();
smp_mb();
schedule_work(&twdr->twkill_work);
need_timer = 1;
} else {

View File

@ -4235,7 +4235,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
* Change state from SYN-SENT only after copied_seq
* is initialized. */
tp->copied_seq = tp->rcv_nxt;
mb();
smp_mb();
tcp_set_state(sk, TCP_ESTABLISHED);
security_inet_conn_established(sk, skb);
@ -4483,7 +4483,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
case TCP_SYN_RECV:
if (acceptable) {
tp->copied_seq = tp->rcv_nxt;
mb();
smp_mb();
tcp_set_state(sk, TCP_ESTABLISHED);
sk->sk_state_change(sk);

View File

@ -660,7 +660,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, struct packe
sll->sll_ifindex = dev->ifindex;
h->tp_status = status;
mb();
smp_mb();
{
struct page *p_start, *p_end;