path: root/net/phonet
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2010-04-29 11:01:49 +0000
committerDavid S. Miller <davem@davemloft.net>2010-05-01 15:00:15 -0700
commit43815482370c510c569fd18edb57afcb0fa8cab6 (patch)
tree063efaae3758402b84f056438b704d1de68f7837 /net/phonet
parent83d7eb2979cd3390c375470225dd2d8f2009bc70 (diff)
net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we need two atomic operations (and associated dirtying) per incoming packet. RCU conversion is pretty much needed : 1) Add a new structure, called "struct socket_wq" to hold all fields that will need rcu_read_lock() protection (currently: a wait_queue_head_t and a struct fasync_struct pointer). [Future patch will add a list anchor for wakeup coalescing] 2) Attach one of such structure to each "struct socket" created in sock_alloc_inode(). 3) Respect RCU grace period when freeing a "struct socket_wq" 4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct socket_wq" 5) Change sk_sleep() function to use new sk->sk_wq instead of sk->sk_sleep 6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside a rcu_read_lock() section. 7) Change all sk_has_sleeper() callers to : - Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock) - Use wq_has_sleeper() to eventually wakeup tasks. - Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock) 8) sock_wake_async() is modified to use rcu protection as well. 9) Exceptions : macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq" instead of dynamically allocated ones. They dont need rcu freeing. Some cleanups or followups are probably needed, (possible sk_callback_lock conversion to a spinlock for example...). Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/phonet')
2 files changed, 5 insertions, 5 deletions
diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index e2a95762abd3..af4d38bc3b22 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -664,12 +664,12 @@ static int pep_wait_connreq(struct sock *sk, int noblock)
if (signal_pending(tsk))
return sock_intr_errno(timeo);
- prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
+ prepare_to_wait_exclusive(sk_sleep(sk), &wait,
timeo = schedule_timeout(timeo);
- finish_wait(&sk->sk_socket->wait, &wait);
+ finish_wait(sk_sleep(sk), &wait);
return 0;
@@ -910,10 +910,10 @@ disabled:
goto out;
- prepare_to_wait(&sk->sk_socket->wait, &wait,
+ prepare_to_wait(sk_sleep(sk), &wait,
done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
- finish_wait(&sk->sk_socket->wait, &wait);
+ finish_wait(sk_sleep(sk), &wait);
if (sk->sk_state != TCP_ESTABLISHED)
goto disabled;
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index c785bfd0744f..6e9848bf0370 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -265,7 +265,7 @@ static unsigned int pn_socket_poll(struct file *file, struct socket *sock,
struct pep_sock *pn = pep_sk(sk);
unsigned int mask = 0;
- poll_wait(file, &sock->wait, wait);
+ poll_wait(file, sk_sleep(sk), wait);
switch (sk->sk_state) {

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