From fdcc8aa953a1123a289791dd192090651036d593 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sun, 8 Nov 2009 10:17:05 +0000
Subject: [PATCH] udp: add a counter into udp_hslot
Adds a counter in udp_hslot to keep an accurate count
of sockets present in chain.
This will permit to upcoming UDP lookup algo to chose
the shortest chain when secondary hash is added.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/udp.h | 8 ++++++++
net/ipv4/udp.c | 3 +++
2 files changed, 11 insertions(+)
diff --git a/include/net/udp.h b/include/net/udp.h
index 22aa2e7eb1d7..9167281e47dc 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -50,8 +50,16 @@ struct udp_skb_cb {
};
#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
+/**
+ * struct udp_hslot - UDP hash slot
+ *
+ * @head: head of list of sockets
+ * @count: number of sockets in 'head' list
+ * @lock: spinlock protecting changes to head/count
+ */
struct udp_hslot {
struct hlist_nulls_head head;
+ int count;
spinlock_t lock;
} __attribute__((aligned(2 * sizeof(long))));
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index d5e75e976513..ffc837643a04 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -218,6 +218,7 @@ int udp_lib_get_port(struct sock *sk, unsigned short snum,
sk->sk_hash = snum;
if (sk_unhashed(sk)) {
sk_nulls_add_node_rcu(sk, &hslot->head);
+ hslot->count++;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
error = 0;
@@ -1053,6 +1054,7 @@ void udp_lib_unhash(struct sock *sk)
spin_lock_bh(&hslot->lock);
if (sk_nulls_del_node_init_rcu(sk)) {
+ hslot->count--;
inet_sk(sk)->inet_num = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
}
@@ -1862,6 +1864,7 @@ void __init udp_table_init(struct udp_table *table, const char *name)
}
for (i = 0; i <= table->mask; i++) {
INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
+ table->hash[i].count = 0;
spin_lock_init(&table->hash[i].lock);
}
}
--
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