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/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))