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/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index 2379750..bbb7742 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -138,6 +138,7 @@
unsigned int sctp_poll(struct file *file, struct socket *sock,
poll_table *wait);
void sctp_sock_rfree(struct sk_buff *skb);
+extern struct percpu_counter sctp_sockets_allocated;
/*
* sctp/primitive.c
diff --git a/include/net/sock.h b/include/net/sock.h
index 00cd486..a2a3890 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -649,7 +649,7 @@
/* Memory pressure */
void (*enter_memory_pressure)(struct sock *sk);
atomic_t *memory_allocated; /* Current allocated memory. */
- atomic_t *sockets_allocated; /* Current number of sockets. */
+ struct percpu_counter *sockets_allocated; /* Current number of sockets. */
/*
* Pressure flag: try to collapse.
* Technical note: it is used by multiple contexts non atomically.
diff --git a/include/net/tcp.h b/include/net/tcp.h
index e8ae90a..cbca3b8 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -238,7 +238,7 @@
extern int sysctl_tcp_max_ssthresh;
extern atomic_t tcp_memory_allocated;
-extern atomic_t tcp_sockets_allocated;
+extern struct percpu_counter tcp_sockets_allocated;
extern int tcp_memory_pressure;
/*
diff --git a/net/core/sock.c b/net/core/sock.c
index a4e840e..7a081b6 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1071,7 +1071,7 @@
newsk->sk_sleep = NULL;
if (newsk->sk_prot->sockets_allocated)
- atomic_inc(newsk->sk_prot->sockets_allocated);
+ percpu_counter_inc(newsk->sk_prot->sockets_allocated);
}
out:
return newsk;
@@ -1463,8 +1463,12 @@
}
if (prot->memory_pressure) {
- if (!*prot->memory_pressure ||
- prot->sysctl_mem[2] > atomic_read(prot->sockets_allocated) *
+ int alloc;
+
+ if (!*prot->memory_pressure)
+ return 1;
+ alloc = percpu_counter_read_positive(prot->sockets_allocated);
+ if (prot->sysctl_mem[2] > alloc *
sk_mem_pages(sk->sk_wmem_queued +
atomic_read(&sk->sk_rmem_alloc) +
sk->sk_forward_alloc))
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 731789b..4944b47 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -55,7 +55,8 @@
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),
- tcp_death_row.tw_count, atomic_read(&tcp_sockets_allocated),
+ tcp_death_row.tw_count,
+ (int)percpu_counter_sum_positive(&tcp_sockets_allocated),
atomic_read(&tcp_memory_allocated));
seq_printf(seq, "UDP: inuse %d mem %d\n",
sock_prot_inuse_get(net, &udp_prot),
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 044224a..e6fade9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -290,9 +290,12 @@
EXPORT_SYMBOL(sysctl_tcp_wmem);
atomic_t tcp_memory_allocated; /* Current allocated memory. */
-atomic_t tcp_sockets_allocated; /* Current number of TCP sockets. */
-
EXPORT_SYMBOL(tcp_memory_allocated);
+
+/*
+ * Current number of TCP sockets.
+ */
+struct percpu_counter tcp_sockets_allocated;
EXPORT_SYMBOL(tcp_sockets_allocated);
/*
@@ -2685,6 +2688,7 @@
BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
+ percpu_counter_init(&tcp_sockets_allocated, 0);
tcp_hashinfo.bind_bucket_cachep =
kmem_cache_create("tcp_bind_bucket",
sizeof(struct inet_bind_bucket), 0,
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index cab2458..26b9030 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1797,7 +1797,7 @@
sk->sk_sndbuf = sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
- atomic_inc(&tcp_sockets_allocated);
+ percpu_counter_inc(&tcp_sockets_allocated);
return 0;
}
@@ -1845,7 +1845,7 @@
sk->sk_sndmsg_page = NULL;
}
- atomic_dec(&tcp_sockets_allocated);
+ percpu_counter_dec(&tcp_sockets_allocated);
}
EXPORT_SYMBOL(tcp_v4_destroy_sock);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index f259c96..8702b06 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1830,7 +1830,7 @@
sk->sk_sndbuf = sysctl_tcp_wmem[1];
sk->sk_rcvbuf = sysctl_tcp_rmem[1];
- atomic_inc(&tcp_sockets_allocated);
+ percpu_counter_inc(&tcp_sockets_allocated);
return 0;
}
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();
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 3a35a6e..5aaf23e 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -571,7 +571,6 @@
static struct proto unix_proto = {
.name = "UNIX",
.owner = THIS_MODULE,
- .sockets_allocated = &unix_nr_socks,
.obj_size = sizeof(struct unix_sock),
};