net: listening_hash get a spinlock per bucket

This patch prepares RCU migration of listening_hash table for
TCP/DCCP protocols.

listening_hash table being small (32 slots per protocol), we add
a spinlock for each slot, instead of a single rwlock for whole table.

This should reduce hold time of readers, and writers concurrency.

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 6 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index bdf784c422b5..8b63394ec24c 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -44,12 +44,7 @@ atomic_t dccp_orphan_count = ATOMIC_INIT(0);
 
 EXPORT_SYMBOL_GPL(dccp_orphan_count);
 
-struct inet_hashinfo __cacheline_aligned dccp_hashinfo = {
-        .lhash_lock     = RW_LOCK_UNLOCKED,
-        .lhash_users    = ATOMIC_INIT(0),
-        .lhash_wait = __WAIT_QUEUE_HEAD_INITIALIZER(dccp_hashinfo.lhash_wait),
-};
-
+struct inet_hashinfo dccp_hashinfo;
 EXPORT_SYMBOL_GPL(dccp_hashinfo);
 
 /* the maximum queue length for tx in packets. 0 is no limit */
@@ -1030,6 +1025,7 @@ static int __init dccp_init(void)
         BUILD_BUG_ON(sizeof(struct dccp_skb_cb) >
                      FIELD_SIZEOF(struct sk_buff, cb));
 
+        inet_hashinfo_init(&dccp_hashinfo);
         dccp_hashinfo.bind_bucket_cachep =
                 kmem_cache_create("dccp_bind_bucket",
                                   sizeof(struct inet_bind_bucket), 0,