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| author | Eric Dumazet <dada1@cosmosbay.com> | 2008-11-25 21:17:14 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-11-25 21:17:14 -0800 |
| commit | dd24c00191d5e4a1ae896aafe33c6b8095ab4bd1 (patch) | |
| tree | e955c09e0b288e50c706b6ee409229d5a930c80c /net/ipv4/tcp.c | |
| parent | 1748376b6626acf59c24e9592ac67b3fe2a0e026 (diff) | |
| download | lwn-dd24c00191d5e4a1ae896aafe33c6b8095ab4bd1.tar.gz lwn-dd24c00191d5e4a1ae896aafe33c6b8095ab4bd1.zip | |
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.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e6fade9ebf62..019243408623 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, |