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authorEric Dumazet <eric.dumazet@gmail.com>2009-11-08 13:17:58 +0300
committerDavid S. Miller <davem@davemloft.net>2009-11-09 07:53:06 +0300
commit512615b6b843ff3ff5ad583f34c39b3f302f5f26 (patch)
tree7420705a314bc691bc478225148935dc67f71904 /include/net/udp.h
parentd4cada4ae1c012815f95fa507eb86a0ae9d607d7 (diff)
downloadlinux-512615b6b843ff3ff5ad583f34c39b3f302f5f26.tar.xz
udp: secondary hash on (local port, local address)
Extends udp_table to contain a secondary hash table. socket anchor for this second hash is free, because UDP doesnt use skc_bind_node : We define an union to hold both skc_bind_node & a new hlist_nulls_node udp_portaddr_node udp_lib_get_port() inserts sockets into second hash chain (additional cost of one atomic op) udp_lib_unhash() deletes socket from second hash chain (additional cost of one atomic op) Note : No spinlock lockdep annotation is needed, because lock for the secondary hash chain is always get after lock for primary hash chain. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/udp.h')
-rw-r--r--include/net/udp.h22
1 files changed, 20 insertions, 2 deletions
diff --git a/include/net/udp.h b/include/net/udp.h
index 9167281e47dc..af41850f742a 100644
--- a/include/net/udp.h
+++ b/include/net/udp.h
@@ -63,10 +63,19 @@ struct udp_hslot {
spinlock_t lock;
} __attribute__((aligned(2 * sizeof(long))));
+/**
+ * struct udp_table - UDP table
+ *
+ * @hash: hash table, sockets are hashed on (local port)
+ * @hash2: hash table, sockets are hashed on (local port, local address)
+ * @mask: number of slots in hash tables, minus 1
+ * @log: log2(number of slots in hash table)
+ */
struct udp_table {
struct udp_hslot *hash;
- unsigned int mask;
- unsigned int log;
+ struct udp_hslot *hash2;
+ unsigned int mask;
+ unsigned int log;
};
extern struct udp_table udp_table;
extern void udp_table_init(struct udp_table *, const char *);
@@ -75,6 +84,15 @@ static inline struct udp_hslot *udp_hashslot(struct udp_table *table,
{
return &table->hash[udp_hashfn(net, num, table->mask)];
}
+/*
+ * For secondary hash, net_hash_mix() is performed before calling
+ * udp_hashslot2(), this explains difference with udp_hashslot()
+ */
+static inline struct udp_hslot *udp_hashslot2(struct udp_table *table,
+ unsigned int hash)
+{
+ return &table->hash2[hash & table->mask];
+}
/* Note: this must match 'valbool' in sock_setsockopt */
#define UDP_CSUM_NOXMIT 1