diff options
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 44c1e934824b..37ca3843c40b 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1946,6 +1946,12 @@ static void *listening_get_idx(struct seq_file *seq, loff_t *pos) return rc; } +static inline int empty_bucket(struct tcp_iter_state *st) +{ + return hlist_empty(&tcp_hashinfo.ehash[st->bucket].chain) && + hlist_empty(&tcp_hashinfo.ehash[st->bucket].twchain); +} + static void *established_get_first(struct seq_file *seq) { struct tcp_iter_state* st = seq->private; @@ -1958,6 +1964,10 @@ static void *established_get_first(struct seq_file *seq) struct inet_timewait_sock *tw; rwlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket); + /* Lockless fast path for the common case of empty buckets */ + if (empty_bucket(st)) + continue; + read_lock_bh(lock); sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) { if (sk->sk_family != st->family || @@ -2008,13 +2018,15 @@ get_tw: read_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); st->state = TCP_SEQ_STATE_ESTABLISHED; - if (++st->bucket < tcp_hashinfo.ehash_size) { - read_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); - sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain); - } else { - cur = NULL; - goto out; - } + /* Look for next non empty bucket */ + while (++st->bucket < tcp_hashinfo.ehash_size && + empty_bucket(st)) + ; + if (st->bucket >= tcp_hashinfo.ehash_size) + return NULL; + + read_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket)); + sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain); } else sk = sk_next(sk); |