tcp_memory_pressure and tcp_socket currently share a cache line with tcp_memory_allocated, tcp_sockets_allocated. (Very hot cache line) It makes sense to declare these variables as __read_mostly, to avoid false sharing on SMP.
ffffffff8081d9c0 B tcp_orphan_count ffffffff8081d9c4 B tcp_memory_allocated ffffffff8081d9c8 B tcp_sockets_allocated ffffffff8081d9cc B tcp_memory_pressure ffffffff8081d9d0 b tcp_md5sig_users ffffffff8081d9d8 b tcp_md5sig_pool ffffffff8081d9e0 b warntime.31570 ffffffff8081d9e8 b tcp_socket Signed-off-by: Eric Dumazet <[EMAIL PROTECTED]> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 18a09a7..bb9d91a 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -297,7 +297,7 @@ EXPORT_SYMBOL(tcp_sockets_allocated); * All the sk_stream_mem_schedule() is of this nature: accounting * is strict, actions are advisory and have some latency. */ -int tcp_memory_pressure; +int tcp_memory_pressure __read_mostly; EXPORT_SYMBOL(tcp_memory_pressure); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index a4c46ee..25aec3e 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -88,7 +88,7 @@ int sysctl_tcp_low_latency __read_mostly #define ICMP_MIN_LENGTH 8 /* Socket used for sending RSTs */ -static struct socket *tcp_socket; +static struct socket *tcp_socket __read_mostly; void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb); - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
