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authorEric Dumazet <dada1@cosmosbay.com>2008-11-25 21:17:14 -0800
committerDavid S. Miller <davem@davemloft.net>2008-11-25 21:17:14 -0800
commitdd24c00191d5e4a1ae896aafe33c6b8095ab4bd1 (patch)
treee955c09e0b288e50c706b6ee409229d5a930c80c /net/ipv4/tcp.c
parent1748376b6626acf59c24e9592ac67b3fe2a0e026 (diff)
net: Use a percpu_counter for orphan_count
Instead of using one atomic_t per protocol, use a percpu_counter for "orphan_count", to reduce cache line contention on heavy duty network servers. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp.c')
-rw-r--r--net/ipv4/tcp.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e6fade9ebf6..01924340862 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -277,8 +277,7 @@
int sysctl_tcp_fin_timeout __read_mostly = TCP_FIN_TIMEOUT;
-atomic_t tcp_orphan_count = ATOMIC_INIT(0);
-
+struct percpu_counter tcp_orphan_count;
EXPORT_SYMBOL_GPL(tcp_orphan_count);
int sysctl_tcp_mem[3] __read_mostly;
@@ -1837,7 +1836,7 @@ adjudge_to_death:
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
- atomic_inc(sk->sk_prot->orphan_count);
+ percpu_counter_inc(sk->sk_prot->orphan_count);
/* It is the last release_sock in its life. It will remove backlog. */
release_sock(sk);
@@ -1888,9 +1887,11 @@ adjudge_to_death:
}
}
if (sk->sk_state != TCP_CLOSE) {
+ int orphan_count = percpu_counter_read_positive(
+ sk->sk_prot->orphan_count);
+
sk_mem_reclaim(sk);
- if (tcp_too_many_orphans(sk,
- atomic_read(sk->sk_prot->orphan_count))) {
+ if (tcp_too_many_orphans(sk, orphan_count)) {
if (net_ratelimit())
printk(KERN_INFO "TCP: too many of orphaned "
"sockets\n");
@@ -2689,6 +2690,7 @@ void __init tcp_init(void)
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
percpu_counter_init(&tcp_sockets_allocated, 0);
+ percpu_counter_init(&tcp_orphan_count, 0);
tcp_hashinfo.bind_bucket_cachep =
kmem_cache_create("tcp_bind_bucket",
sizeof(struct inet_bind_bucket), 0,