ospf: Convert MAX_AGE LSA list to tree
Store the MaxAge LSA list in a tree instead of a linked list for efficient access.
Walking the list can be quite inefficient in some large systems and under certain tests.
ospfd maintains the list of LSA's that have been MaxAge'd out in a separate
linked list for removal by a remover/walker thread. When a new LSA is to be
installed, the old LSA is ejected and when it is ejected, the MaxAge LSA list
is traversed to ensure that the old LSA is also removed from this list if it
exists on this list.
When a large number (> 5K) MaxAge LSAs are bombarding the system, walking this
list takes a significant time causing timers to fire and actions to be taken
such as expiring neighbors due to expiry of DeadInterval (especially when timer
is really low, <= 12s), creating a spiral of instability.
By making this MaxAge LSA list be a tree, this problem is mitigated.
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Reviewed-by: Ayan Banerjee <ayan@cumulusnetworks.com>
Reviewed-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Reviewed-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
diff --git a/ospfd/ospfd.h b/ospfd/ospfd.h
index dfaef1d..cc27f66 100644
--- a/ospfd/ospfd.h
+++ b/ospfd/ospfd.h
@@ -248,7 +248,7 @@
/* Time stamps. */
struct timeval ts_spf; /* SPF calculation time stamp. */
- struct list *maxage_lsa; /* List of MaxAge LSA for deletion. */
+ struct route_table *maxage_lsa; /* List of MaxAge LSA for deletion. */
int redistribute; /* Num of redistributed protocols. */
/* Threads. */