bgpd: Optimizing route-map's processing of dependencies.

Say for eg., 256 prefix-list entries are pasted to VTYSH.
This results in BGP processing the events for several minutes.

BGPD starts a timer for 5 seconds when the first dependency configuraion
is received. On timer expiry, BGP process dependent route-maps.
After this processing, BGPD reads the configurations received in the
next 5 seconds and then re-processes the route-maps from the beginning.
This cyclic re-processing consumes time and CPU cycles.

Instead of starting a timer when the first configuration is received,
everytime a configuration is received, the existing timer is reset.
This would mean that all the configurations are read first before the timer
expires. This eliminates the cyclic re-processing.

Signed-off-by: NaveenThanikachalam nthanikachal@vmware.com

diff --git a/bgpd/bgp_routemap.c b/bgpd/bgp_routemap.c
index 5ffc416dc5237e6db23ac8857b013740d8b7cdf4..7f1a9b71c137f6ba1b63426890785eb448c7bec8 100644 (file)
--- a/bgpd/bgp_routemap.c
+++ b/bgpd/bgp_routemap.c
@@ -3406,31 +3406,34 @@ int bgp_route_map_update_timer(struct thread *thread)
 
 static void bgp_route_map_mark_update(const char *rmap_name)
 {
-       if (bm->t_rmap_update == NULL) {
-               struct listnode *node, *nnode;
-               struct bgp *bgp;
-
-               /* rmap_update_timer of 0 means don't do route updates */
-               if (bm->rmap_update_timer) {
-                       bm->t_rmap_update = NULL;
-                       thread_add_timer(bm->master, bgp_route_map_update_timer,
-                                        NULL, bm->rmap_update_timer,
-                                        &bm->t_rmap_update);
-
-                       /* Signal the groups that a route-map update event has
-                        * started */
-                       for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp))
-                               update_group_policy_update(bgp,
-                                                          BGP_POLICY_ROUTE_MAP,
-                                                          rmap_name, 1, 1);
-               } else {
-                       for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp))
-                               bgp_route_map_process_update(bgp, rmap_name, 0);
+       struct listnode *node, *nnode;
+       struct bgp *bgp;
+
+       /* If new update is received before the current timer timed out,
+        * turn it off and start a new timer.
+        */
+       if (bm->t_rmap_update != NULL)
+               THREAD_OFF(bm->t_rmap_update);
+
+       /* rmap_update_timer of 0 means don't do route updates */
+       if (bm->rmap_update_timer) {
+               thread_add_timer(bm->master, bgp_route_map_update_timer,
+                                NULL, bm->rmap_update_timer,
+                                &bm->t_rmap_update);
+
+               /* Signal the groups that a route-map update event has
+                * started */
+               for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp))
+                       update_group_policy_update(bgp,
+                                                  BGP_POLICY_ROUTE_MAP,
+                                                  rmap_name, 1, 1);
+       } else {
+               for (ALL_LIST_ELEMENTS(bm->bgp, node, nnode, bgp))
+                       bgp_route_map_process_update(bgp, rmap_name, 0);
 #if ENABLE_BGP_VNC
-                       zlog_debug("%s: calling vnc_routemap_update", __func__);
-                       vnc_routemap_update(bgp, __func__);
+               zlog_debug("%s: calling vnc_routemap_update", __func__);
+               vnc_routemap_update(bgp, __func__);
 #endif
-               }
        }
 }