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/protocol.c b/net/sctp/protocol.c
index a8ca743..d5ea232 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -102,6 +102,8 @@
/* Set up the proc fs entry for the SCTP protocol. */
static __init int sctp_proc_init(void)
{
+ if (percpu_counter_init(&sctp_sockets_allocated, 0))
+ goto out_nomem;
#ifdef CONFIG_PROC_FS
if (!proc_net_sctp) {
struct proc_dir_entry *ent;
@@ -110,7 +112,7 @@
ent->owner = THIS_MODULE;
proc_net_sctp = ent;
} else
- goto out_nomem;
+ goto out_free_percpu;
}
if (sctp_snmp_proc_init())
@@ -135,6 +137,8 @@
proc_net_sctp = NULL;
remove_proc_entry("sctp", init_net.proc_net);
}
+out_free_percpu:
+ percpu_counter_destroy(&sctp_sockets_allocated);
out_nomem:
return -ENOMEM;
#else
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();