llc: use a device based hash table to speed up multicast delivery
This patch adds a per SAP device based hash table to solve the
multicast delivery scalability issue when we have large number of
interfaces and a large number of sockets bound to the same SAP.
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/llc.h b/include/net/llc.h
index 1559cf1..dbef591 100644
--- a/include/net/llc.h
+++ b/include/net/llc.h
@@ -32,6 +32,9 @@
#define LLC_SAP_STATE_INACTIVE 1
#define LLC_SAP_STATE_ACTIVE 2
+#define LLC_SK_DEV_HASH_BITS 6
+#define LLC_SK_DEV_HASH_ENTRIES (1<<LLC_SK_DEV_HASH_BITS)
+
/**
* struct llc_sap - Defines the SAP component
*
@@ -56,8 +59,16 @@
struct list_head node;
spinlock_t sk_lock;
struct hlist_nulls_head sk_list;
+ struct hlist_head sk_dev_hash[LLC_SK_DEV_HASH_ENTRIES];
};
+static inline
+struct hlist_head *llc_sk_dev_hash(struct llc_sap *sap, int ifindex)
+{
+ return &sap->sk_dev_hash[ifindex % LLC_SK_DEV_HASH_ENTRIES];
+}
+
+
#define LLC_DEST_INVALID 0 /* Invalid LLC PDU type */
#define LLC_DEST_SAP 1 /* Type 1 goes here */
#define LLC_DEST_CONN 2 /* Type 2 goes here */
diff --git a/include/net/llc_conn.h b/include/net/llc_conn.h
index fe982fd..2f97d8d 100644
--- a/include/net/llc_conn.h
+++ b/include/net/llc_conn.h
@@ -77,6 +77,7 @@
received and caused sending FRMR.
Used for resending FRMR */
u32 cmsg_flags;
+ struct hlist_node dev_hash_node;
};
static inline struct llc_sock *llc_sk(const struct sock *sk)
diff --git a/net/llc/llc_conn.c b/net/llc/llc_conn.c
index 77bb381..10cdfe2 100644
--- a/net/llc/llc_conn.c
+++ b/net/llc/llc_conn.c
@@ -682,10 +682,15 @@
*/
void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
{
+ struct llc_sock *llc = llc_sk(sk);
+ struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
+
llc_sap_hold(sap);
- spin_lock_bh(&sap->sk_lock);
llc_sk(sk)->sap = sap;
+
+ spin_lock_bh(&sap->sk_lock);
sk_nulls_add_node_rcu(sk, &sap->sk_list);
+ hlist_add_head(&llc->dev_hash_node, dev_hb);
spin_unlock_bh(&sap->sk_lock);
}
@@ -699,8 +704,11 @@
*/
void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
{
+ struct llc_sock *llc = llc_sk(sk);
+
spin_lock_bh(&sap->sk_lock);
sk_nulls_del_node_init_rcu(sk);
+ hlist_del(&llc->dev_hash_node);
spin_unlock_bh(&sap->sk_lock);
llc_sap_put(sap);
}
diff --git a/net/llc/llc_sap.c b/net/llc/llc_sap.c
index 94790e6..94cb706 100644
--- a/net/llc/llc_sap.c
+++ b/net/llc/llc_sap.c
@@ -387,10 +387,14 @@
{
int i = 0, count = 256 / sizeof(struct sock *);
struct sock *sk, *stack[count];
- struct hlist_nulls_node *node;
+ struct hlist_node *node;
+ struct llc_sock *llc;
+ struct hlist_head *dev_hb = llc_sk_dev_hash(sap, skb->dev->ifindex);
spin_lock_bh(&sap->sk_lock);
- sk_nulls_for_each_rcu(sk, node, &sap->sk_list) {
+ hlist_for_each_entry(llc, node, dev_hb, dev_hash_node) {
+
+ sk = &llc->sk;
if (!llc_mcast_match(sap, laddr, skb, sk))
continue;