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authorEric Dumazet <dada1@cosmosbay.com>2007-11-07 02:40:20 -0800
committerDavid S. Miller <davem@sunset.davemloft.net>2007-11-07 04:15:11 -0800
commit230140cffa7feae90ad50bf259db1fa07674f3a7 (patch)
tree815472add31606423a508a17806b7884f0ab3e2e /net
parent[IPVS]: Synchronize closing of Connections (diff)
downloadlinux-dev-230140cffa7feae90ad50bf259db1fa07674f3a7.tar.xz
linux-dev-230140cffa7feae90ad50bf259db1fa07674f3a7.zip
[INET]: Remove per bucket rwlock in tcp/dccp ehash table.
As done two years ago on IP route cache table (commit 22c047ccbc68fa8f3fa57f0e8f906479a062c426) , we can avoid using one lock per hash bucket for the huge TCP/DCCP hash tables. On a typical x86_64 platform, this saves about 2MB or 4MB of ram, for litle performance differences. (we hit a different cache line for the rwlock, but then the bucket cache line have a better sharing factor among cpus, since we dirty it less often). For netstat or ss commands that want a full scan of hash table, we perform fewer memory accesses. Using a 'small' table of hashed rwlocks should be more than enough to provide correct SMP concurrency between different buckets, without using too much memory. Sizing of this table depends on num_possible_cpus() and various CONFIG settings. This patch provides some locking abstraction that may ease a future work using a different model for TCP/DCCP table. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/dccp/proto.c9
-rw-r--r--net/ipv4/inet_diag.c9
-rw-r--r--net/ipv4/inet_hashtables.c7
-rw-r--r--net/ipv4/inet_timewait_sock.c13
-rw-r--r--net/ipv4/tcp.c4
-rw-r--r--net/ipv4/tcp_ipv4.c11
-rw-r--r--net/ipv6/inet6_hashtables.c19
7 files changed, 41 insertions, 31 deletions
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index d84973928033..7a3bea9c28c1 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1072,11 +1072,13 @@ static int __init dccp_init(void)
}
for (i = 0; i < dccp_hashinfo.ehash_size; i++) {
- rwlock_init(&dccp_hashinfo.ehash[i].lock);
INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].chain);
INIT_HLIST_HEAD(&dccp_hashinfo.ehash[i].twchain);
}
+ if (inet_ehash_locks_alloc(&dccp_hashinfo))
+ goto out_free_dccp_ehash;
+
bhash_order = ehash_order;
do {
@@ -1091,7 +1093,7 @@ static int __init dccp_init(void)
if (!dccp_hashinfo.bhash) {
DCCP_CRIT("Failed to allocate DCCP bind hash table");
- goto out_free_dccp_ehash;
+ goto out_free_dccp_locks;
}
for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
@@ -1121,6 +1123,8 @@ out_free_dccp_mib:
out_free_dccp_bhash:
free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
dccp_hashinfo.bhash = NULL;
+out_free_dccp_locks:
+ inet_ehash_locks_free(&dccp_hashinfo);
out_free_dccp_ehash:
free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
dccp_hashinfo.ehash = NULL;
@@ -1139,6 +1143,7 @@ static void __exit dccp_fini(void)
free_pages((unsigned long)dccp_hashinfo.ehash,
get_order(dccp_hashinfo.ehash_size *
sizeof(struct inet_ehash_bucket)));
+ inet_ehash_locks_free(&dccp_hashinfo);
kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
dccp_ackvec_exit();
dccp_sysctl_exit();
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index dc429b6b0ba6..b0170732b5e9 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -747,13 +747,14 @@ skip_listen_ht:
for (i = s_i; i < hashinfo->ehash_size; i++) {
struct inet_ehash_bucket *head = &hashinfo->ehash[i];
+ rwlock_t *lock = inet_ehash_lockp(hashinfo, i);
struct sock *sk;
struct hlist_node *node;
if (i > s_i)
s_num = 0;
- read_lock_bh(&head->lock);
+ read_lock_bh(lock);
num = 0;
sk_for_each(sk, node, &head->chain) {
struct inet_sock *inet = inet_sk(sk);
@@ -769,7 +770,7 @@ skip_listen_ht:
r->id.idiag_dport)
goto next_normal;
if (inet_csk_diag_dump(sk, skb, cb) < 0) {
- read_unlock_bh(&head->lock);
+ read_unlock_bh(lock);
goto done;
}
next_normal:
@@ -791,14 +792,14 @@ next_normal:
r->id.idiag_dport)
goto next_dying;
if (inet_twsk_diag_dump(tw, skb, cb) < 0) {
- read_unlock_bh(&head->lock);
+ read_unlock_bh(lock);
goto done;
}
next_dying:
++num;
}
}
- read_unlock_bh(&head->lock);
+ read_unlock_bh(lock);
}
done:
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 16eecc7046a3..67704da04fc4 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -204,12 +204,13 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row,
const __portpair ports = INET_COMBINED_PORTS(inet->dport, lport);
unsigned int hash = inet_ehashfn(daddr, lport, saddr, inet->dport);
struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
+ rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
struct sock *sk2;
const struct hlist_node *node;
struct inet_timewait_sock *tw;
prefetch(head->chain.first);
- write_lock(&head->lock);
+ write_lock(lock);
/* Check TIME-WAIT sockets first. */
sk_for_each(sk2, node, &head->twchain) {
@@ -239,7 +240,7 @@ unique:
BUG_TRAP(sk_unhashed(sk));
__sk_add_node(sk, &head->chain);
sock_prot_inc_use(sk->sk_prot);
- write_unlock(&head->lock);
+ write_unlock(lock);
if (twp) {
*twp = tw;
@@ -255,7 +256,7 @@ unique:
return 0;
not_unique:
- write_unlock(&head->lock);
+ write_unlock(lock);
return -EADDRNOTAVAIL;
}
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 4e189e28f306..a60b99e0ebdc 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. */
- struct inet_ehash_bucket *ehead = inet_ehash_bucket(hashinfo, tw->tw_hash);
+ rwlock_t *lock = inet_ehash_lockp(hashinfo, tw->tw_hash);
- write_lock(&ehead->lock);
+ write_lock(lock);
if (hlist_unhashed(&tw->tw_node)) {
- write_unlock(&ehead->lock);
+ write_unlock(lock);
return;
}
__hlist_del(&tw->tw_node);
sk_node_init(&tw->tw_node);
- write_unlock(&ehead->lock);
+ write_unlock(lock);
/* Disassociate with bind bucket. */
bhead = &hashinfo->bhash[inet_bhashfn(tw->tw_num, hashinfo->bhash_size)];
@@ -59,6 +59,7 @@ 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);
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
@@ -71,7 +72,7 @@ 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(&ehead->lock);
+ write_lock(lock);
/* Step 2: Remove SK from established hash. */
if (__sk_del_node_init(sk))
@@ -81,7 +82,7 @@ void __inet_twsk_hashdance(struct inet_timewait_sock *tw, struct sock *sk,
inet_twsk_add_node(tw, &ehead->twchain);
atomic_inc(&tw->tw_refcnt);
- write_unlock(&ehead->lock);
+ write_unlock(lock);
}
EXPORT_SYMBOL_GPL(__inet_twsk_hashdance);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c64072bb504b..8e65182f7af1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2456,11 +2456,11 @@ void __init tcp_init(void)
thash_entries ? 0 : 512 * 1024);
tcp_hashinfo.ehash_size = 1 << tcp_hashinfo.ehash_size;
for (i = 0; i < tcp_hashinfo.ehash_size; i++) {
- rwlock_init(&tcp_hashinfo.ehash[i].lock);
INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].chain);
INIT_HLIST_HEAD(&tcp_hashinfo.ehash[i].twchain);
}
-
+ if (inet_ehash_locks_alloc(&tcp_hashinfo))
+ panic("TCP: failed to alloc ehash_locks");
tcp_hashinfo.bhash =
alloc_large_system_hash("TCP bind",
sizeof(struct inet_bind_hashbucket),
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index e9127cdced20..e566f3c67677 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2049,8 +2049,9 @@ static void *established_get_first(struct seq_file *seq)
struct sock *sk;
struct hlist_node *node;
struct inet_timewait_sock *tw;
+ rwlock_t *lock = inet_ehash_lockp(&tcp_hashinfo, st->bucket);
- read_lock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
+ read_lock_bh(lock);
sk_for_each(sk, node, &tcp_hashinfo.ehash[st->bucket].chain) {
if (sk->sk_family != st->family) {
continue;
@@ -2067,7 +2068,7 @@ static void *established_get_first(struct seq_file *seq)
rc = tw;
goto out;
}
- read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
+ read_unlock_bh(lock);
st->state = TCP_SEQ_STATE_ESTABLISHED;
}
out:
@@ -2094,11 +2095,11 @@ get_tw:
cur = tw;
goto out;
}
- read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
+ 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(&tcp_hashinfo.ehash[st->bucket].lock);
+ read_lock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
sk = sk_head(&tcp_hashinfo.ehash[st->bucket].chain);
} else {
cur = NULL;
@@ -2206,7 +2207,7 @@ static void tcp_seq_stop(struct seq_file *seq, void *v)
case TCP_SEQ_STATE_TIME_WAIT:
case TCP_SEQ_STATE_ESTABLISHED:
if (v)
- read_unlock_bh(&tcp_hashinfo.ehash[st->bucket].lock);
+ read_unlock_bh(inet_ehash_lockp(&tcp_hashinfo, st->bucket));
break;
}
}
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index d6f1026f1943..adc73adadfae 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -37,9 +37,8 @@ void __inet6_hash(struct inet_hashinfo *hashinfo,
} else {
unsigned int hash;
sk->sk_hash = hash = inet6_sk_ehashfn(sk);
- hash &= (hashinfo->ehash_size - 1);
- list = &hashinfo->ehash[hash].chain;
- lock = &hashinfo->ehash[hash].lock;
+ list = &inet_ehash_bucket(hashinfo, hash)->chain;
+ lock = inet_ehash_lockp(hashinfo, hash);
write_lock(lock);
}
@@ -70,9 +69,10 @@ struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
*/
unsigned int hash = inet6_ehashfn(daddr, hnum, saddr, sport);
struct inet_ehash_bucket *head = inet_ehash_bucket(hashinfo, hash);
+ rwlock_t *lock = inet_ehash_lockp(hashinfo, hash);
prefetch(head->chain.first);
- read_lock(&head->lock);
+ read_lock(lock);
sk_for_each(sk, node, &head->chain) {
/* For IPV6 do the cheaper port and family tests first. */
if (INET6_MATCH(sk, hash, saddr, daddr, ports, dif))
@@ -92,12 +92,12 @@ struct sock *__inet6_lookup_established(struct inet_hashinfo *hashinfo,
goto hit;
}
}
- read_unlock(&head->lock);
+ read_unlock(lock);
return NULL;
hit:
sock_hold(sk);
- read_unlock(&head->lock);
+ read_unlock(lock);
return sk;
}
EXPORT_SYMBOL(__inet6_lookup_established);
@@ -175,12 +175,13 @@ static int __inet6_check_established(struct inet_timewait_death_row *death_row,
const unsigned int hash = inet6_ehashfn(daddr, lport, saddr,
inet->dport);
struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
+ rwlock_t *lock = inet_ehash_lockp(hinfo, hash);
struct sock *sk2;
const struct hlist_node *node;
struct inet_timewait_sock *tw;
prefetch(head->chain.first);
- write_lock(&head->lock);
+ write_lock(lock);
/* Check TIME-WAIT sockets first. */
sk_for_each(sk2, node, &head->twchain) {
@@ -216,7 +217,7 @@ unique:
__sk_add_node(sk, &head->chain);
sk->sk_hash = hash;
sock_prot_inc_use(sk->sk_prot);
- write_unlock(&head->lock);
+ write_unlock(lock);
if (twp != NULL) {
*twp = tw;
@@ -231,7 +232,7 @@ unique:
return 0;
not_unique:
- write_unlock(&head->lock);
+ write_unlock(lock);
return -EADDRNOTAVAIL;
}