Table prune routine doesn't walk over lists unless needed.

If no channel is flushing, table prune doesn't walk over routes in nets
and also doesn't walk over importing channel lists. This helps to
alleviate the memory caching burdens a lot.

3 files changed, 43 insertions, 24 deletions

diff --git a/nest/rt-attr.c b/nest/rt-attr.c
index b41e56c2..761ec0d9 100644
--- a/nest/rt-attr.c
+++ b/nest/rt-attr.c
@@ -568,6 +568,8 @@ static struct resclass ea_class_ref_class = {
 static void
 ea_class_init(void)
 {
+  ASSERT_DIE(ea_class_global == NULL);
+
   idm_init(&ea_class_idm, rta_pool, EA_CLASS_INITIAL_MAX);
   ea_class_global = mb_allocz(rta_pool,
       sizeof(*ea_class_global) * (ea_class_max = EA_CLASS_INITIAL_MAX));
diff --git a/nest/rt-table.c b/nest/rt-table.c
index f4ca9170..e712796b 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1515,6 +1515,7 @@ rt_export_hook(void *_data)
   }
 
   int used = 0;
+  int no_next = 0;
 
   /* Process the export */
   for (uint i=0; i<RT_EXPORT_BULK; i++)
@@ -1522,12 +1523,16 @@ rt_export_hook(void *_data)
     used += rte_export(c, c->rpe_next);
 
     if (!c->rpe_next)
+    {
+      no_next = 1;
       break;
+    }
   }
 
   if (used)
-    RT_LOCKED(tab, _)
-      rt_export_used(c->table, c->h.req->name, "finished export bulk");
+    RT_LOCKED(tab, t)
+      if (no_next || t->cork_active)
+	rt_export_used(c->table, c->h.req->name, no_next ? "finished export bulk" : "cork active");
 
   rt_send_export_event(&c->h);
 }
@@ -2058,10 +2063,11 @@ rt_stop_import(struct rt_import_request *req, void (*stopped)(struct rt_import_r
     rt_set_import_state(hook, TIS_STOP);
     hook->stopped = stopped;
 
+    /* Cancel table rr_counter */
     if (hook->stale_set != hook->stale_pruned)
-      tab->rr_counter -= (hook->stale_set - hook->stale_pruned - 1);
-    else
-      tab->rr_counter++;
+      tab->rr_counter -= (hook->stale_set - hook->stale_pruned);
+
+    tab->rr_counter++;
 
     hook->stale_set = hook->stale_pruned = hook->stale_pruning = hook->stale_valid = 0;
   }
@@ -2222,7 +2228,7 @@ rt_table_export_stop_locked(struct rt_export_hook *hh)
   switch (atomic_load_explicit(&hh->export_state, memory_order_relaxed))
   {
     case TES_HUNGRY:
-      rt_trace(tab, D_EVENTS, "Stopping export hook %s must wait for uncorking; %p", hook->h.req->name, hook->h.n.next);
+      rt_trace(tab, D_EVENTS, "Stopping export hook %s must wait for uncorking", hook->h.req->name);
       return 0;
     case TES_FEEDING:
       switch (hh->req->addr_mode)
@@ -2241,7 +2247,10 @@ rt_table_export_stop_locked(struct rt_export_hook *hh)
 	  fit_get(&tab->fib, &hook->feed_fit);
 	  break;
       }
+      break;
 
+    case TES_STOP:
+      bug("Tried to repeatedly stop the same export hook %s", hook->h.req->name);
   }
 
   rt_trace(tab, D_EVENTS, "Stopping export hook %s right now", hook->h.req->name);
@@ -2332,7 +2341,7 @@ rt_refresh_begin(struct rt_import_request *req)
            e->rte.stale_cycle = 0;
       }
     FIB_WALK_END;
-    tab->rr_counter -= (hook->stale_set - hook->stale_pruned - 1);
+    tab->rr_counter -= hook->stale_set - hook->stale_pruned;
     hook->stale_set = 1;
     hook->stale_valid = 0;
     hook->stale_pruned = 0;
@@ -2343,9 +2352,11 @@ rt_refresh_begin(struct rt_import_request *req)
     /* Let's reserve the stale_cycle zero value for always-invalid routes */
     hook->stale_set = 1;
     hook->stale_valid = 0;
-    tab->rr_counter++;
   }
 
+  /* The table must know that we're route-refreshing */
+  tab->rr_counter++;
+
   if (req->trace_routes & D_STATES)
     log(L_TRACE "%s: route refresh begin [%u]", req->name, hook->stale_set);
 
@@ -2371,6 +2382,7 @@ rt_refresh_end(struct rt_import_request *req)
     hook->stale_valid++;
     ASSERT_DIE(hook->stale_set == hook->stale_valid);
 
+    /* Here we can't kick the timer as we aren't in the table service loop */
     rt_schedule_prune(tab);
 
     if (req->trace_routes & D_STATES)
@@ -2853,7 +2865,7 @@ rt_setup(pool *pp, struct rtable_config *cf)
   }
 
   /* Start the service thread */
-  t->loop = birdloop_new(p, DOMAIN_ORDER(service), mb_sprintf(p, "Routing tahle %s", t->name));
+  t->loop = birdloop_new(p, DOMAIN_ORDER(service), mb_sprintf(p, "Routing table %s", t->name));
   birdloop_enter(t->loop);
   birdloop_flag_set_handler(t->loop, &t->fh);
   birdloop_leave(t->loop);
@@ -3021,27 +3033,27 @@ again:
     }
   }
 
-  uint flushed_channels = 0;
-
   /* Close flushed channels */
   WALK_LIST2_DELSAFE(ih, n, x, tab->imports, n)
     if (ih->import_state == TIS_FLUSHING)
     {
+      DBG("flushing %s %s rr %u", ih->req->name, tab->name, tab->rr_counter);
       ih->flush_seq = tab->exporter.next_seq;
       rt_set_import_state(ih, TIS_WAITING);
-      flushed_channels++;
       tab->rr_counter--;
+      tab->wait_counter++;
     }
     else if (ih->stale_pruning != ih->stale_pruned)
     {
-      tab->rr_counter -= (ih->stale_pruned - ih->stale_pruning);
+      DBG("pruning %s %s rr %u set %u valid %u pruning %u pruned %u", ih->req->name, tab->name, tab->rr_counter, ih->stale_set, ih->stale_valid, ih->stale_pruning, ih->stale_pruned);
+      tab->rr_counter -= (ih->stale_pruning - ih->stale_pruned);
       ih->stale_pruned = ih->stale_pruning;
       if (ih->req->trace_routes & D_STATES)
 	log(L_TRACE "%s: table prune after refresh end [%u]", ih->req->name, ih->stale_pruned);
     }
 
   /* In some cases, we may want to directly proceed to export cleanup */
-  if (EMPTY_LIST(tab->exporter.e.hooks) && flushed_channels)
+  if (EMPTY_LIST(tab->exporter.e.hooks) && tab->wait_counter)
     rt_export_cleanup(tab);
 }
 
@@ -3202,13 +3214,15 @@ rt_export_cleanup(struct rtable_private *tab)
 
 done:;
   struct rt_import_hook *ih; node *x;
-  WALK_LIST2_DELSAFE(ih, n, x, tab->imports, n)
-    if (ih->import_state == TIS_WAITING)
-      if (!first || (first->seq >= ih->flush_seq))
-      {
-	ih->import_state = TIS_CLEARED;
-	ev_send(ih->req->list, &ih->announce_event);
-      }
+  if (tab->wait_counter)
+    WALK_LIST2_DELSAFE(ih, n, x, tab->imports, n)
+      if (ih->import_state == TIS_WAITING)
+	if (!first || (first->seq >= ih->flush_seq))
+	{
+	  ih->import_state = TIS_CLEARED;
+	  tab->wait_counter--;
+	  ev_send(ih->req->list, &ih->announce_event);
+	}
 
   if ((tab->gc_counter += want_prune) >= tab->config->gc_threshold)
     rt_kick_prune_timer(tab);
@@ -3287,7 +3301,7 @@ rt_unlock_trie(struct rtable_private *tab, struct f_trie *trie)
       if (tab->trie && (tab->trie->prefix_count > (2 * tab->fib.entries)))
       {
 	tab->prune_trie = 1;
-	rt_schedule_prune(tab);
+	rt_kick_prune_timer(tab);
       }
     }
   }
@@ -3940,8 +3954,8 @@ rt_new_table(struct symbol *s, uint addr_type)
   c->addr_type = addr_type;
   c->gc_threshold = 1000;
   c->gc_period = (uint) -1;	/* set in rt_postconfig() */
-  c->cork_threshold.low = 128;
-  c->cork_threshold.high = 512;
+  c->cork_threshold.low = 1024;
+  c->cork_threshold.high = 8192;
   c->export_settle = (struct settle_config) {
     .min = 1 MS,
     .max = 100 MS,
@@ -4042,6 +4056,7 @@ rt_check_cork_high(struct rtable_private *tab)
   {
     tab->cork_active = 1;
     rt_cork_acquire();
+    rt_export_used(&tab->exporter, tab->name, "corked");
 
     rt_trace(tab, D_STATES, "Corked");
   }
diff --git a/nest/rt.h b/nest/rt.h
index 6ee2ce9b..cceb5edf 100644
--- a/nest/rt.h
+++ b/nest/rt.h
@@ -141,8 +141,10 @@ struct rtable_private {
   uint rr_counter;			/* Number of currently running route refreshes,
 					   in fact sum of (stale_set - stale_pruned) over all importers
 					   + one for each TIS_FLUSHING importer */
+  uint wait_counter;			/* Number of imports in TIS_WAITING state */
   byte prune_state;			/* Table prune state, 1 -> scheduled, 2-> running */
   byte prune_trie;			/* Prune prefix trie during next table prune */
+  byte imports_flushing;		/* Some imports are being flushed right now */
   byte nhu_state;			/* Next Hop Update state */
   byte nhu_corked;			/* Next Hop Update is corked with this state */
   byte export_used;			/* Pending Export pruning is scheduled */