path: root/net/ipv4/tcp.c
diff options
authorEric Dumazet <edumazet@google.com>2013-10-03 00:22:02 -0700
committerDavid S. Miller <davem@davemloft.net>2013-10-08 23:19:24 -0400
commit05dbc7b59481ca891bbcfe6799a562d48159fbf7 (patch)
treef398ddbc5d2a72b3c3b7b16aed8a34b153491341 /net/ipv4/tcp.c
parent53af53ae83fe960ceb9ef74cac7915e9088f4266 (diff)
tcp/dccp: remove twchain
TCP listener refactoring, part 3 : Our goal is to hash SYN_RECV sockets into main ehash for fast lookup, and parallel SYN processing. Current inet_ehash_bucket contains two chains, one for ESTABLISH (and friend states) sockets, another for TIME_WAIT sockets only. As the hash table is sized to get at most one socket per bucket, it makes little sense to have separate twchain, as it makes the lookup slightly more complicated, and doubles hash table memory usage. If we make sure all socket types have the lookup keys at the same offsets, we can use a generic and faster lookup. It turns out TIME_WAIT and ESTABLISHED sockets already have common lookup fields for IPv4. [ INET_TW_MATCH() is no longer needed ] I'll provide a follow-up to factorize IPv6 lookup as well, to remove INET6_TW_MATCH() This way, SYN_RECV pseudo sockets will be supported the same. A new sock_gen_put() helper is added, doing either a sock_put() or inet_twsk_put() [ and will support SYN_RECV later ]. Note this helper should only be called in real slow path, when rcu lookup found a socket that was moved to another identity (freed/reused immediately), but could eventually be used in other contexts, like sock_edemux() Before patch : dmesg | grep "TCP established" TCP established hash table entries: 524288 (order: 11, 8388608 bytes) After patch : TCP established hash table entries: 524288 (order: 10, 4194304 bytes) Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
1 files changed, 2 insertions, 3 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 6e5617b9f9db..be4b161802e8 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3137,10 +3137,9 @@ void __init tcp_init(void)
thash_entries ? 0 : 512 * 1024);
- for (i = 0; i <= tcp_hashinfo.ehash_mask; i++) {
+ for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
- INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].twchain, i);
- }
if (inet_ehash_locks_alloc(&tcp_hashinfo))
panic("TCP: failed to alloc ehash_locks");
tcp_hashinfo.bhash =