net: Use a percpu_counter for orphan_count
Instead of using one atomic_t per protocol, use a percpu_counter
for "orphan_count", to reduce cache line contention on
heavy duty network servers.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index ea85c42..db225f9 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -40,8 +40,7 @@
EXPORT_SYMBOL_GPL(dccp_statistics);
-atomic_t dccp_orphan_count = ATOMIC_INIT(0);
-
+struct percpu_counter dccp_orphan_count;
EXPORT_SYMBOL_GPL(dccp_orphan_count);
struct inet_hashinfo dccp_hashinfo;
@@ -1000,7 +999,7 @@
state = sk->sk_state;
sock_hold(sk);
sock_orphan(sk);
- atomic_inc(sk->sk_prot->orphan_count);
+ percpu_counter_inc(sk->sk_prot->orphan_count);
/*
* It is the last release_sock in its life. It will remove backlog.
@@ -1064,18 +1063,21 @@
{
unsigned long goal;
int ehash_order, bhash_order, i;
- int rc = -ENOBUFS;
+ int rc;
BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
FIELD_SIZEOF(struct sk_buff, cb));
-
+ rc = percpu_counter_init(&dccp_orphan_count, 0);
+ if (rc)
+ goto out;
+ rc = -ENOBUFS;
inet_hashinfo_init(&dccp_hashinfo);
dccp_hashinfo.bind_bucket_cachep =
kmem_cache_create("dccp_bind_bucket",
sizeof(struct inet_bind_bucket), 0,
SLAB_HWCACHE_ALIGN, NULL);
if (!dccp_hashinfo.bind_bucket_cachep)
- goto out;
+ goto out_free_percpu;
/*
* Size and allocate the main established and bind bucket
@@ -1168,6 +1170,8 @@
out_free_bind_bucket_cachep:
kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
dccp_hashinfo.bind_bucket_cachep = NULL;
+out_free_percpu:
+ percpu_counter_destroy(&dccp_orphan_count);
goto out;
}