From 5caea4ea7088e80ac5410d04660346094608b909 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 20 Nov 2008 00:40:07 -0800 Subject: net: listening_hash get a spinlock per bucket This patch prepares RCU migration of listening_hash table for TCP/DCCP protocols. listening_hash table being small (32 slots per protocol), we add a spinlock for each slot, instead of a single rwlock for whole table. This should reduce hold time of readers, and writers concurrency. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_ipv4.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'net/ipv4/tcp_ipv4.c') diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 5559fea..330b08a 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -97,11 +97,7 @@ struct tcp_md5sig_key *tcp_v4_md5_do_lookup(struct sock *sk, __be32 addr) } #endif -struct inet_hashinfo __cacheline_aligned tcp_hashinfo = { - .lhash_lock = __RW_LOCK_UNLOCKED(tcp_hashinfo.lhash_lock), - .lhash_users = ATOMIC_INIT(0), - .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.lhash_wait), -}; +struct inet_hashinfo tcp_hashinfo; static inline __u32 tcp_v4_init_sequence(struct sk_buff *skb) { @@ -1874,15 +1870,18 @@ static void *listening_get_next(struct seq_file *seq, void *cur) struct inet_connection_sock *icsk; struct hlist_node *node; struct sock *sk = cur; + struct inet_listen_hashbucket *ilb; struct tcp_iter_state *st = seq->private; struct net *net = seq_file_net(seq); if (!sk) { st->bucket = 0; - sk = sk_head(&tcp_hashinfo.listening_hash[0]); + ilb = &tcp_hashinfo.listening_hash[0]; + spin_lock_bh(&ilb->lock); + sk = sk_head(&ilb->head); goto get_sk; } - + ilb = &tcp_hashinfo.listening_hash[st->bucket]; ++st->num; if (st->state == TCP_SEQ_STATE_OPENREQ) { @@ -1932,8 +1931,11 @@ start_req: } read_unlock_bh(&icsk->icsk_accept_queue.syn_wait_lock); } + spin_unlock_bh(&ilb->lock); if (++st->bucket < INET_LHTABLE_SIZE) { - sk = sk_head(&tcp_hashinfo.listening_hash[st->bucket]); + ilb = &tcp_hashinfo.listening_hash[st->bucket]; + spin_lock_bh(&ilb->lock); + sk = sk_head(&ilb->head); goto get_sk; } cur = NULL; @@ -2066,12 +2068,10 @@ static void *tcp_get_idx(struct seq_file *seq, loff_t pos) void *rc; struct tcp_iter_state *st = seq->private; - inet_listen_lock(&tcp_hashinfo); st->state = TCP_SEQ_STATE_LISTENING; rc = listening_get_idx(seq, &pos); if (!rc) { - inet_listen_unlock(&tcp_hashinfo); st->state = TCP_SEQ_STATE_ESTABLISHED; rc = established_get_idx(seq, pos); } @@ -2103,7 +2103,6 @@ static void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos) case TCP_SEQ_STATE_LISTENING: rc = listening_get_next(seq, v); if (!rc) { - inet_listen_unlock(&tcp_hashinfo); st->state = TCP_SEQ_STATE_ESTABLISHED; rc = established_get_first(seq); } @@ -2130,7 +2129,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v) } case TCP_SEQ_STATE_LISTENING: if (v != SEQ_START_TOKEN) - inet_listen_unlock(&tcp_hashinfo); + spin_unlock_bh(&tcp_hashinfo.listening_hash[st->bucket].lock); break; case TCP_SEQ_STATE_TIME_WAIT: case TCP_SEQ_STATE_ESTABLISHED: @@ -2405,6 +2404,7 @@ static struct pernet_operations __net_initdata tcp_sk_ops = { void __init tcp_v4_init(void) { + inet_hashinfo_init(&tcp_hashinfo); if (register_pernet_device(&tcp_sk_ops)) panic("Failed to create the TCP control socket.\n"); } -- cgit v1.1