From 9db66bdcc83749affe61c61eb8ff3cf08f42afec Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 20 Nov 2008 20:39:09 -0800 Subject: net: convert TCP/DCCP ehash rwlocks to spinlocks Now TCP & DCCP use RCU lookups, we can convert ehash rwlocks to spinlocks. /proc/net/tcp and other seq_file 'readers' can safely be converted to 'writers'. This should speedup writers, since spin_lock()/spin_unlock() only use one atomic operation instead of two for write_lock()/write_unlock() Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/inet_timewait_sock.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'net/ipv4/inet_timewait_sock.c') diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 60689951ecdb..8554d0ea1719 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -20,16 +20,16 @@ static void __inet_twsk_kill(struct inet_timewait_sock *tw, struct inet_bind_hashbucket *bhead; struct inet_bind_bucket *tb; /* Unlink from established hashes. */ - rwlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash); + spinlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash); - write_lock(lock); + spin_lock(lock); if (hlist_nulls_unhashed(&tw->tw_node)) { - write_unlock(lock); + spin_unlock(lock); return; } hlist_nulls_del_rcu(&tw->tw_node); sk_nulls_node_init(&tw->tw_node); - write_unlock(lock); + spin_unlock(lock); /* Disassociate with bind bucket. */ bhead = &hashinfo->bhash[inet_bhashfn(twsk_net(tw), tw->tw_num, @@ -76,7 +76,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, const struct inet_sock *inet = inet_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, sk->sk_hash); - rwlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash); + spinlock_t *lock = inet_ehash_lockp(hashinfo, sk->sk_hash); struct inet_bind_hashbucket *bhead; /* Step 1: Put TW into bind hash. Original socket stays there too. Note, that any socket with inet->num != 0 MUST be bound in @@ -90,7 +90,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, inet_twsk_add_bind_node(tw, &tw->tw_tb->owners); spin_unlock(&bhead->lock); - write_lock(lock); + spin_lock(lock); /* * Step 2: Hash TW into TIMEWAIT chain. @@ -104,7 +104,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk, if (__sk_nulls_del_node_init_rcu(sk)) sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - write_unlock(lock); + spin_unlock(lock); } EXPORT_SYMBOL_GPL(__inet_twsk_hashdance); @@ -427,9 +427,9 @@ void inet_twsk_purge(struct net *net, struct inet_hashinfo *hashinfo, for (h = 0; h < (hashinfo->ehash_size); h++) { struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, h); - rwlock_t *lock = inet_ehash_lockp(hashinfo, h); + spinlock_t *lock = inet_ehash_lockp(hashinfo, h); restart: - write_lock(lock); + spin_lock(lock); sk_nulls_for_each(sk, node, &head->twchain) { tw = inet_twsk(sk); @@ -438,13 +438,13 @@ restart: continue; atomic_inc(&tw->tw_refcnt); - write_unlock(lock); + spin_unlock(lock); inet_twsk_deschedule(tw, twdr); inet_twsk_put(tw); goto restart; } - write_unlock(lock); + spin_unlock(lock); } local_bh_enable(); } -- cgit v1.2.3-59-g8ed1b