path: root/net/dccp/timer.c
diff options
authorEric Dumazet <eric.dumazet@gmail.com>2010-04-08 23:03:29 +0000
committerDavid S. Miller <davem@davemloft.net>2010-04-13 01:41:33 -0700
commitb6c6712a42ca3f9fa7f4a3d7c40e3a9dd1fd9e03 (patch)
tree42032b4978874e8ffcf6c851d13324b8c8c7c113 /net/dccp/timer.c
parentnet: Dont use netdev_warn() (diff)
net: sk_dst_cache RCUification
With latest CONFIG_PROVE_RCU stuff, I felt more comfortable to make this work. sk->sk_dst_cache is currently protected by a rwlock (sk_dst_lock) This rwlock is readlocked for a very small amount of time, and dst entries are already freed after RCU grace period. This calls for RCU again :) This patch converts sk_dst_lock to a spinlock, and use RCU for readers. __sk_dst_get() is supposed to be called with rcu_read_lock() or if socket locked by user, so use appropriate rcu_dereference_check() condition (rcu_read_lock_held() || sock_owned_by_user(sk)) This patch avoids two atomic ops per tx packet on UDP connected sockets, for example, and permits sk_dst_lock to be much less dirtied. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp/timer.c')
1 files changed, 2 insertions, 2 deletions
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index bbfeb5eae46a..1a9aa05d4dc4 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -38,7 +38,7 @@ static int dccp_write_timeout(struct sock *sk)
if (sk->sk_state == DCCP_REQUESTING || sk->sk_state == DCCP_PARTOPEN) {
if (icsk->icsk_retransmits != 0)
- dst_negative_advice(&sk->sk_dst_cache, sk);
+ dst_negative_advice(sk);
retry_until = icsk->icsk_syn_retries ?
: sysctl_dccp_request_retries;
} else {
@@ -63,7 +63,7 @@ static int dccp_write_timeout(struct sock *sk)
Golden words :-).
- dst_negative_advice(&sk->sk_dst_cache, sk);
+ dst_negative_advice(sk);
retry_until = sysctl_dccp_retries2;