[TCP]: tcp_memory_pressure and tcp_socket are__read_mostly candidates

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 <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2007-03-27 13:58:31 -07:00 committed by David S. Miller
parent 73417f617a
commit 4103f8cd5c
2 changed files with 2 additions and 2 deletions

View file

@ -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);

View file

@ -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);