[MINOR] disable useless hint in wake_expired_tasks

wake_expired_tasks() used a hint to avoid scanning the tree in most cases,
but it looks like the hint is more expensive than reaching the first node
in the tree. Disable it for now.

diff --git a/src/task.c b/src/task.c
index 8d9d10c..6190670 100644 (file)
--- a/src/task.c
+++ b/src/task.c
@@ -88,9 +88,12 @@ void wake_expired_tasks(struct timeval *next)
        struct task *task;
        void *data;
 
+#ifdef WAKE_HINT_CHECK_FIRST
        /*
         * Hint: tasks are *rarely* expired. So we can try to optimize
-        * by not scanning the tree at all in most cases.
+        * by not scanning the tree at all in most cases. However, this
+        * code costs 160 more bytes which do not look much useful because
+        * the performance win is not obvious.
         */
 
        if (likely(timer_wq.data != NULL)) {
@@ -100,16 +103,15 @@ void wake_expired_tasks(struct timeval *next)
                        return;
                }
        }
-
        /* OK we lose. Let's scan the tree then. */
-       tv_eternity(next);
+#endif
 
        tree64_foreach(&timer_wq, data, stack, slen) {
                task = LIST_ELEM(data, struct task *, qlist);
 
                if (tv_isgt(&task->expire, &now)) {
                        *next = task->expire;
-                       break;
+                       return;
                }
 
                /*
@@ -124,6 +126,7 @@ void wake_expired_tasks(struct timeval *next)
                        task->state = TASK_RUNNING;
                }
        }
+       tv_eternity(next);
        return;
 }