* Mathieu Desnoyers (mathieu.desnoyers@efficios.com) wrote:

* Sasha Levin (levinsasha928@gmail.com) wrote:
[...]

quoted

@@ -158,34 +159,21 @@ static int dlm_allow_conn;
 static struct workqueue_struct *recv_workqueue;
 static struct workqueue_struct *send_workqueue;
 
-static struct hlist_head connection_hash[CONN_HASH_SIZE];
+static struct hlist_head connection_hash[CONN_HASH_BITS];
 static DEFINE_MUTEX(connections_lock);
 static struct kmem_cache *con_cache;
 
 static void process_recv_sockets(struct work_struct *work);
 static void process_send_sockets(struct work_struct *work);
 
-
-/* This is deliberately very simple because most clusters have simple
-   sequential nodeids, so we should be able to go straight to a connection
-   struct in the array */
-static inline int nodeid_hash(int nodeid)
-{
-	return nodeid & (CONN_HASH_SIZE-1);
-}

There is one thing I dislike about this change: you remove a useful
comment. It's good to be informed of the reason why a direct mapping
"value -> hash" without any dispersion function is preferred here.

And now that I come to think of it: you're changing the behavior : you
will now use a dispersion function on the key, which goes against the
intent expressed in this comment.

It might be good to change hash_add(), hash_add_rcu(),
hash_for_each_possible*() key parameter for a "hash" parameter, and let
the caller provide the hash value computed by the function they like as
parameter, rather than enforcing hash_32/hash_64.

Thoughts ?

Thanks,

Mathieu

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com

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