controller: Reduce the time it takes to remove multiple ports.

Multichassis reprocessing could increase the time for processing
the removal of ports. The issue is we could actually process
multiple ports over and over if there did belong into single
datapath. To prevent that create set of ports that were already
reprocessed for the multichassis in the current I-P run and do
not reprocess them again. This greatly reduces the amount of
precessing during removal as shown below with the test that
removes 1000 ports in a single transaction.

Without:
physical_flow_output, handler for input runtime_data took 992ms

With:
physical_flow_output, handler for input runtime_data took 58ms

Reported-at: https://issues.redhat.com/browse/FDP-1012
Signed-off-by: Ales Musil <[email protected]>
Signed-off-by: Dumitru Ceara <[email protected]>
(cherry picked from commit f62e525)

controller/ovn-controller.c

@@ -4353,6 +4353,7 @@ static void init_physical_ctx(struct engine_node *node,
     p_ctx->if_mgr = ctrl_ctx->if_mgr;
 
     pflow_output_get_debug(node, &p_ctx->debug);
+    sset_init(&p_ctx->reprocessed_pbs);
 }
 
 static void
@@ -4362,6 +4363,7 @@ destroy_physical_ctx(struct physical_ctx *p_ctx)
         free((char *)(p_ctx->encap_ips[i]));
     }
     free(p_ctx->encap_ips);
+    sset_destroy(&p_ctx->reprocessed_pbs);
 }
 
 static void *

controller/physical.c

@@ -2438,6 +2438,11 @@ physical_multichassis_reprocess(const struct sbrec_port_binding *pb,
     const struct sbrec_port_binding *port;
     SBREC_PORT_BINDING_FOR_EACH_EQUAL (port, target,
                                        p_ctx->sbrec_port_binding_by_datapath) {
+        /* Ignore PBs that were already reprocessed. */
+        if (!sset_add(&p_ctx->reprocessed_pbs, port->logical_port)) {
+            continue;
+        }
+
         ofctrl_remove_flows(flow_table, &port->header_.uuid);
         physical_eval_port_binding(p_ctx, port, flow_table);
     }

controller/physical.h

@@ -70,6 +70,9 @@ struct physical_ctx {
     const char **encap_ips;
     struct physical_debug debug;
     bool always_tunnel;
+    /* Set of port binding names that have been already reprocessed during
+     * the I-P run. */
+    struct sset reprocessed_pbs;
 };
 
 void physical_register_ovs_idl(struct ovsdb_idl *);