Expose the real maxmeminqueues via a GETINFO

That is, GETINFO limits/max-mem-in-queues

changes/bug11396

@@ -5,3 +5,7 @@
       the default was always 8 GB. You can still override the default by
       setting MaxMemInQueues yourself. Resolves ticket 11396.
 
+  o Minor features (controller):
+    - Because of the fix for ticket 11396, the real limit for memory
+      usage may no longer match the configured MaxMemInQueues value.
+      The real limit is now exposed via GETINFO limits/max-mem-in-queues.

src/or/control.c

@@ -1504,6 +1504,9 @@ getinfo_helper_misc(control_connection_t *conn, const char *question,
     int max_fds=-1;
     set_max_file_descriptors(0, &max_fds);
     tor_asprintf(answer, "%d", max_fds);
+  } else if (!strcmp(question, "limits/max-mem-in-queues")) {
+    tor_asprintf(answer, U64_FORMAT,
+                 U64_PRINTF_ARG(get_options()->MaxMemInQueues));
   } else if (!strcmp(question, "dir-usage")) {
     *answer = directory_dump_request_log();
   } else if (!strcmp(question, "fingerprint")) {
@@ -2184,6 +2187,7 @@ static const getinfo_item_t getinfo_items[] = {
   ITEM("process/user", misc,
        "Username under which the tor process is running."),
   ITEM("process/descriptor-limit", misc, "File descriptor limit."),
+  ITEM("limits/max-mem-in-queues", misc, "Actual limit on memory in queues"),
   ITEM("dir-usage", misc, "Breakdown of bytes transferred over DirPort."),
   PREFIX("desc-annotations/id/", dir, "Router annotations by hexdigest."),
   PREFIX("dir/server/", dir,"Router descriptors as retrieved from a DirPort."),