tipc: add option to suppress PUBLISH events for pre-existing publications

Currently, when a user is subscribing for binding table publications,
he will receive a PUBLISH event for all already existing matching items
in the binding table.

However, a group socket making a subscriptions doesn't need this initial
status update from the binding table, because it has already scanned it
during the join operation. Worse, the multiplicatory effect of issuing
mutual events for dozens or hundreds group members within a short time
frame put a heavy load on the topology server, with the end result that
scale out operations on a big group tend to take much longer than needed.

We now add a new filter option, TIPC_SUB_NO_STATUS, for topology server
subscriptions, so that this initial avalanche of events is suppressed.
This change, along with the previous commit, significantly improves the
range and speed of group scale out operations.

We keep the new option internal for the tipc driver, at least for now.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/tipc/name_table.h b/net/tipc/name_table.h
index 71926e429446..73a148c85c15 100644
--- a/net/tipc/name_table.h
+++ b/net/tipc/name_table.h
@@ -121,7 +121,7 @@ struct publication *tipc_nametbl_insert_publ(struct net *net, u32 type,
 struct publication *tipc_nametbl_remove_publ(struct net *net, u32 type,
 					     u32 lower, u32 node, u32 ref,
 					     u32 key);
-void tipc_nametbl_subscribe(struct tipc_subscription *s);
+void tipc_nametbl_subscribe(struct tipc_subscription *s, bool status);
 void tipc_nametbl_unsubscribe(struct tipc_subscription *s);
 int tipc_nametbl_init(struct net *net);
 void tipc_nametbl_stop(struct net *net);