net: Use a percpu_counter for sockets_allocated
Instead of using one atomic_t per protocol, use a percpu_counter
for "sockets_allocated", to reduce cache line contention on
heavy duty network servers.
Note : We revert commit (248969ae31e1b3276fc4399d67ce29a5d81e6fd9
net: af_unix can make unix_nr_socks visbile in /proc),
since it is not anymore used after sock_prot_inuse_add() addition
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index ba81fe3..a2de5858 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -114,7 +114,7 @@
static int sctp_memory_pressure;
static atomic_t sctp_memory_allocated;
-static atomic_t sctp_sockets_allocated;
+struct percpu_counter sctp_sockets_allocated;
static void sctp_enter_memory_pressure(struct sock *sk)
{
@@ -3613,7 +3613,7 @@
sp->hmac = NULL;
SCTP_DBG_OBJCNT_INC(sock);
- atomic_inc(&sctp_sockets_allocated);
+ percpu_counter_inc(&sctp_sockets_allocated);
local_bh_disable();
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
@@ -3632,7 +3632,7 @@
/* Release our hold on the endpoint. */
ep = sctp_sk(sk)->ep;
sctp_endpoint_free(ep);
- atomic_dec(&sctp_sockets_allocated);
+ percpu_counter_dec(&sctp_sockets_allocated);
local_bh_disable();
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
local_bh_enable();
