Route table import-to-export announcement indirection to reduce pipe traffic

nest/proto.c

@@ -468,6 +468,7 @@ channel_start_import(struct channel *c)
 
   c->in_req = (struct rt_import_request) {
     .name = rn,
+    .list = proto_work_list(c->proto),
     .trace_routes = c->debug | c->proto->debug,
     .dump_req = channel_dump_import_req,
     .log_state_change = channel_import_log_state_change,
@@ -886,6 +887,7 @@ channel_setup_in_table(struct channel *c, int best)
   c->in_table = &cat->cat;
   c->in_table->push = (struct rt_import_request) {
     .name = cat->name,
+    .list = proto_work_list(c->proto),
     .trace_routes = c->debug | c->proto->debug,
     .dump_req = channel_in_push_dump_req,
     .log_state_change = channel_push_log_state_change,
@@ -928,6 +930,7 @@ channel_setup_out_table(struct channel *c)
   c->out_table = &cat->cat;
   c->out_table->push = (struct rt_import_request) {
     .name = cat->name,
+    .list = proto_work_list(c->proto),
     .trace_routes = c->debug | c->proto->debug,
     .dump_req = channel_out_push_dump_req,
     .log_state_change = channel_push_log_state_change,

nest/route.h

@@ -170,6 +170,7 @@ typedef struct rtable_private {
   struct hmap id_map;
   struct hostcache *hostcache;
   struct event *prune_event;		/* Event to prune abandoned routes */
+  struct event *announce_event;		/* Event to announce pending exports */
   struct event *ec_event;		/* Event to prune finished exports */
   struct event *hcu_event;		/* Event to update host cache */
   struct event *delete_event;		/* Event to delete the table */
@@ -191,8 +192,6 @@ typedef struct rtable_private {
   struct timer *settle_timer;		/* Settle time for notifications */
 
   list pending_exports;			/* List of packed struct rt_pending_export */
-  btime base_export_time;		/* When first pending export was announced */
-  struct timer *export_timer;
 
   struct rt_pending_export *first_export;	/* First export to announce */
   u64 next_export_seq;			/* The next export will have this ID */
@@ -221,7 +220,6 @@ struct rtable_config {
   byte sorted;				/* Routes of network are sorted according to rte_better() */
   btime min_settle_time;		/* Minimum settle time for notifications */
   btime max_settle_time;		/* Maximum settle time for notifications */
-  btime export_settle_time;		/* Delay before exports are announced */
   uint cork_limit;			/* Amount of routes to be pending on export to cork imports */
 };
 
@@ -309,6 +307,8 @@ struct rt_import_request {
   char *name;
   u8 trace_routes;
 
+  event_list *list;			/* Where to schedule import events */
+
   void (*dump_req)(struct rt_import_request *req);
   void (*log_state_change)(struct rt_import_request *req, u8 state);
   /* Preimport is called when the @new route is just-to-be inserted, replacing @old.
@@ -339,6 +339,7 @@ struct rt_import_hook {
   u8 stale_pruned;			/* Last prune finished when this value was set at stale_valid */
   u8 stale_pruning;			/* Last prune started when this value was set at stale_valid */
 
+  struct event *export_announce_event;	/* Event to run to announce new exports */
   struct event *stopped;		/* Event to run when import is stopped */
 };
 

nest/rt-table.c

@@ -1023,8 +1023,6 @@ rte_announce(rtable_private *tab, net *net, struct rte_storage *new, struct rte_
       rt_notify_hostcache(tab, net);
   }
 
-  rt_schedule_notify(tab);
-
   if (EMPTY_LIST(tab->exports) && EMPTY_LIST(tab->pending_exports))
   {
     /* No export hook and no pending exports to cleanup. We may free the route immediately. */
@@ -1105,10 +1103,7 @@ rte_announce(rtable_private *tab, net *net, struct rte_storage *new, struct rte_
   {
     ev_cork(&rt_cork);
     tab->cork_active = 1;
-    tm_start_in(tab->export_timer, 0, tab->loop);
   }
-  else if (!tm_active(tab->export_timer))
-    tm_start_in(tab->export_timer, tab->config->export_settle_time, tab->loop);
 }
 
 static struct rt_pending_export *
@@ -1158,11 +1153,13 @@ rt_send_export_event(struct rt_export_hook *hook)
 }
 
 static void
-rt_announce_exports(timer *tm)
+rt_announce_exports(void *data)
 {
-  rtable_private *tab = tm->data;
+  rtable_private *tab = data;
   ASSERT_DIE(birdloop_inside(tab->loop));
 
+  rt_schedule_notify(tab);
+
   struct rt_export_hook *c; node *n;
   WALK_LIST2(c, n, tab->exports, n)
   {
@@ -1173,6 +1170,26 @@ rt_announce_exports(timer *tm)
   }
 }
 
+static void
+rt_import_announce_exports(void *data)
+{
+  struct rt_import_hook *hook = data;
+  RT_LOCKED(hook->table, tab)
+  {
+    if (hook->import_state == TIS_CLEARED)
+    {
+      rfree(hook->export_announce_event);
+
+      ev_send(hook->stopped->list, hook->stopped);
+      rem_node(&hook->n);
+      mb_free(hook);
+      rt_unlock_table(tab);
+    }
+    else
+      ev_send_loop(tab->loop, tab->announce_event);
+  }
+}
+
 static struct rt_pending_export *
 rt_last_export(rtable_private *tab)
 {
@@ -1471,6 +1488,8 @@ rte_recalculate(rtable_private *table, struct rt_import_hook *c, net *net, rte *
   rte_announce(table, net, new_stored, old_stored,
       net->routes, old_best_stored);
 
+  ev_send(req->list, c->export_announce_event);
+
   if (!net->routes &&
       (table->gc_counter++ >= table->config->gc_max_ops) &&
       (table->gc_time + table->config->gc_min_time <= current_time()))
@@ -1709,6 +1728,8 @@ rt_request_import(rtable *t, struct rt_import_request *req)
   hook->req = req;
   hook->table = t;
 
+  hook->export_announce_event = ev_new_init(tab->rp, rt_import_announce_exports, hook);
+
   if (!hook->stale_set)
     hook->stale_set = hook->stale_valid = hook->stale_pruning = hook->stale_pruned = 1;
 
@@ -1727,11 +1748,12 @@ rt_stop_import(struct rt_import_request *req, event *stopped)
   struct rt_import_hook *hook = req->hook;
 
   RT_LOCK(hook->table);
+
   rt_schedule_prune(RT_PRIV(hook->table));
 
   rt_set_import_state(hook, TIS_STOP);
-
   hook->stopped = stopped;
+
   RT_UNLOCK(hook->table);
 }
 
@@ -2158,6 +2180,7 @@ rt_setup(pool *pp, struct rtable_config *cf)
 
   t->loop = birdloop_new(p, DOMAIN_ORDER(rtable), nb);
 
+  t->announce_event = ev_new_init(p, rt_announce_exports, t);
   t->ec_event = ev_new_init(p, rt_export_cleanup, t);
   t->prune_event = ev_new_init(p, rt_prune_table, t);
   t->hcu_event = ev_new_init(p, rt_update_hostcache, t);
@@ -2166,7 +2189,6 @@ rt_setup(pool *pp, struct rtable_config *cf)
   t->nhu_event->cork = &rt_cork;
   t->prune_event->cork = &rt_cork;
 
-  t->export_timer = tm_new_init(p, rt_announce_exports, t, 0, 0);
   t->last_rt_change = t->gc_time = current_time();
   t->next_export_seq = 1;
 
@@ -2472,15 +2494,11 @@ done:;
       if (!first_export || (first_export->seq >= ih->flush_seq))
       {
 	ih->import_state = TIS_CLEARED;
-	ev_send(ih->stopped->list, ih->stopped);
+	ev_send(ih->req->list, ih->export_announce_event);
-	rem_node(&ih->n);
-	mb_free(ih);
-	rt_unlock_table(tab);
       }
 
-
+  if (EMPTY_LIST(tab->pending_exports) && ev_active(tab->announce_event))
-  if (EMPTY_LIST(tab->pending_exports) && tm_active(tab->export_timer))
+    ev_postpone(tab->announce_event);
-    tm_stop(tab->export_timer);
 
   /* If reduced to at most one export block pending */
   if (tab->cork_active &&
@@ -2753,6 +2771,8 @@ rt_next_hop_update(void *data)
   if (atomic_fetch_and_explicit(&tab->nhu_state, NHU_SCHEDULED, memory_order_acq_rel) != NHU_RUNNING)
     ev_send_loop(tab->loop, tab->nhu_event);
 
+  ev_send_loop(tab->loop, tab->announce_event);
+
   rt_unlock_table(tab);
 }
 
@@ -2809,6 +2829,7 @@ rt_loop_stopped(void *data)
   r->loop = NULL;
   r->prune_event->list = r->ec_event->list = NULL;
   r->nhu_event->list = r->hcu_event->list = NULL;
+  r->announce_event->list = NULL;
   ev_send(r->delete_event->list, r->delete_event);
 }