[ovs-dev] [RFC 1/2] OVN: add meter support to trigger_event action

[Lorenzo Bianconi]

Introduce meter support to trigger_event action in order to not
overload pinctrl thread under heavy load

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi at redhat.com>
---
 include/ovn/actions.h |  1 +
 ovn/lib/actions.c     | 42 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/include/ovn/actions.h b/include/ovn/actions.h
index 63d3907d8..1f2ac2eb2 100644
--- a/include/ovn/actions.h
+++ b/include/ovn/actions.h
@@ -326,6 +326,7 @@ struct ovnact_controller_event {
     int event_type;   /* controller event type */
     struct ovnact_gen_option *options;
     size_t n_options;
+    char *meter;
 };
 
 /* Internal use by the helpers below. */
diff --git a/ovn/lib/actions.c b/ovn/lib/actions.c
index 4eacc44ed..2e321d82e 100644
--- a/ovn/lib/actions.c
+++ b/ovn/lib/actions.c
@@ -1273,6 +1273,9 @@ format_TRIGGER_EVENT(const struct ovnact_controller_event *event,
 {
     ds_put_format(s, "trigger_event(event = \"%s\"",
                   event_to_string(event->event_type));
+    if (event->meter) {
+        ds_put_format(s, ", meter = \"%s\"", event->meter);
+    }
     for (const struct ovnact_gen_option *o = event->options;
          o < &event->options[event->n_options]; o++) {
         ds_put_cstr(s, ", ");
@@ -1420,10 +1423,21 @@ encode_TRIGGER_EVENT(const struct ovnact_controller_event *event,
                      const struct ovnact_encode_params *ep OVS_UNUSED,
                      struct ofpbuf *ofpacts)
 {
+    uint32_t meter_id = NX_CTLR_NO_METER;
     size_t oc_offset;
 
+    if (event->meter) {
+        meter_id = ovn_extend_table_assign_id(ep->meter_table, event->meter,
+                                              ep->lflow_uuid);
+        if (meter_id == EXT_TABLE_ID_INVALID) {
+            VLOG_WARN("Unable to assign id for trigger meter: %s",
+                      event->meter);
+            return;
+        }
+    }
+
     oc_offset = encode_start_controller_op(ACTION_OPCODE_EVENT, false,
-                                           NX_CTLR_NO_METER, ofpacts);
+                                           meter_id, ofpacts);
     ovs_be32 ofs = htonl(event->event_type);
     ofpbuf_put(ofpacts, &ofs, sizeof ofs);
 
@@ -1738,11 +1752,27 @@ parse_trigger_event(struct action_context *ctx,
                                      sizeof *event->options);
         }
 
-        struct ovnact_gen_option *o = &event->options[event->n_options++];
-        memset(o, 0, sizeof *o);
-        parse_gen_opt(ctx, o,
-                      &ctx->pp->controller_event_opts->event_opts[event_type],
-                      event_to_string(event_type));
+        if (lexer_match_id(ctx->lexer, "meter")) {
+            if (!lexer_force_match(ctx->lexer, LEX_T_EQUALS)) {
+                return;
+            }
+            /* If multiple meters are given, use the most recent. */
+            if (ctx->lexer->token.type == LEX_T_STRING &&
+                strlen(ctx->lexer->token.s)) {
+                free(event->meter);
+                event->meter = xstrdup(ctx->lexer->token.s);
+            } else if (ctx->lexer->token.type != LEX_T_STRING) {
+                lexer_syntax_error(ctx->lexer, "expecting string");
+                return;
+            }
+            lexer_get(ctx->lexer);
+        } else {
+            struct ovnact_gen_option *o = &event->options[event->n_options++];
+            memset(o, 0, sizeof *o);
+            parse_gen_opt(ctx, o,
+                    &ctx->pp->controller_event_opts->event_opts[event_type],
+                    event_to_string(event_type));
+            }
         if (ctx->lexer->error) {
             return;
         }
-- 
2.21.0