[Sheepdog] [PATCH 1/4] sheep: reduce the size of join message

[Liu Yuan]

On 10/20/2011 07:33 PM, MORITA Kazutaka wrote:

> Signed-off-by: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
> ---
>  sheep/group.c |   51 ++++++++++++++++++++++++++++++++++-----------------
>  1 files changed, 34 insertions(+), 17 deletions(-)
> 
> diff --git a/sheep/group.c b/sheep/group.c
> index 7e4531d..04fec41 100644
> --- a/sheep/group.c
> +++ b/sheep/group.c
> @@ -49,8 +49,8 @@ struct join_message {
>  	uint8_t inc_epoch; /* set non-zero when we increment epoch of all nodes */
>  	uint8_t pad[3];
>  	union {
> -		struct sheepdog_node_list_entry nodes[SD_MAX_NODES];
> -		struct sheepdog_node_list_entry leave_nodes[SD_MAX_NODES];
> +		struct sheepdog_node_list_entry nodes[0];
> +		struct sheepdog_node_list_entry leave_nodes[0];

>  	};
>  };
>  
> @@ -74,7 +74,7 @@ struct work_join {
>  	size_t member_list_entries;
>  	struct sheepdog_node_list_entry joined;
>  
> -	struct join_message jm;
> +	struct join_message *jm;
>  };
>  
>  struct work_leave {
> @@ -100,6 +100,13 @@ struct work_leave {
>  
>  static int cpg_event_running;
>  
> +static size_t get_join_message_size(struct join_message *jm)
> +{
> +	/* jm->nr_nodes is always larger than jm->nr_leave_nodes, so
> +	 * it is safe to use jm->nr_nodes. */
> +	return sizeof(*jm) + jm->nr_nodes * sizeof(jm->nodes[0]);
> +}
> +
>  static int get_node_idx(struct sheepdog_node_list_entry *ent,
>  			struct sheepdog_node_list_entry *entries, int nr_nodes)
>  {
> @@ -863,7 +870,7 @@ static int check_majority(struct sheepdog_node_list_entry *nodes, int nr_nodes)
>  static void __sd_join(struct cpg_event *cevent)
>  {
>  	struct work_join *w = container_of(cevent, struct work_join, cev);
> -	struct join_message *msg = &w->jm;
> +	struct join_message *msg = w->jm;
>  	int i;
>  
>  	if (msg->cluster_status != SD_STATUS_OK)
> @@ -953,23 +960,29 @@ static enum cluster_join_result sd_check_join_cb(
>  
>  static int send_join_request(struct sheepdog_node_list_entry *ent)
>  {
> -	struct join_message msg;
> +	struct join_message *msg;
>  	int nr_entries, ret;
>  
> -	memset(&msg, 0, sizeof(msg));
> -	msg.header.proto_ver = SD_SHEEP_PROTO_VER;
> -	msg.header.msg_length = sizeof(msg);
> -	msg.header.from = *ent;
> +	msg = zalloc(sizeof(*msg) * SD_MAX_NODES * sizeof(msg->nodes[0]));


zalloc(sizeof(*msg) + ...) ?

Yuan