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>
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 05af807..1ccdbba 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -561,7 +561,7 @@
sk_refcnt_debug_release(sk);
- atomic_dec(sk->sk_prot->orphan_count);
+ percpu_counter_dec(sk->sk_prot->orphan_count);
sock_put(sk);
}
@@ -641,7 +641,7 @@
sock_orphan(child);
- atomic_inc(sk->sk_prot->orphan_count);
+ percpu_counter_inc(sk->sk_prot->orphan_count);
inet_csk_destroy_sock(child);
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 4944b47..614958b 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -54,7 +54,7 @@
socket_seq_show(seq);
seq_printf(seq, "TCP: inuse %d orphan %d tw %d alloc %d mem %d\n",
sock_prot_inuse_get(net, &tcp_prot),
- atomic_read(&tcp_orphan_count),
+ (int)percpu_counter_sum_positive(&tcp_orphan_count),
tcp_death_row.tw_count,
(int)percpu_counter_sum_positive(&tcp_sockets_allocated),
atomic_read(&tcp_memory_allocated));
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index e6fade9..0192434 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 @@
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 @@
}
}
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 @@
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,
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 3df339e..cc4e6d2 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -65,7 +65,7 @@
static int tcp_out_of_resources(struct sock *sk, int do_reset)
{
struct tcp_sock *tp = tcp_sk(sk);
- int orphans = atomic_read(&tcp_orphan_count);
+ int orphans = percpu_counter_read_positive(&tcp_orphan_count);
/* If peer does not open window for long time, or did not transmit
* anything for long time, penalize it. */