no longer create drift tasks for sub-tasks.

src/scheduler.c

@@ -176,13 +176,6 @@ static void scheduler_splittask(struct task *t, struct scheduler *s) {
           /* Depend on local sorts on this cell. */
           if (ci->sorts != NULL) scheduler_addunlock(s, ci->sorts, t);
 
-          /* Add a drift task to this cell. */
-          lock_lock(&ci->lock);
-          if (ci->drift == NULL)
-            ci->drift = scheduler_addtask(s, task_type_drift, task_subtype_none,
-                                          0, 0, ci, NULL, 0);
-          lock_unlock_blind(&ci->lock);
-
           /* Otherwise, make tasks explicitly. */
         } else {
 
@@ -253,18 +246,6 @@ static void scheduler_splittask(struct task *t, struct scheduler *s) {
           if (ci->sorts != NULL) scheduler_addunlock(s, ci->sorts, t);
           if (cj->sorts != NULL) scheduler_addunlock(s, cj->sorts, t);
 
-          /* Add a drift task to the cells, if needed. */
-          lock_lock(&ci->lock);
-          if (ci->drift == NULL)
-            ci->drift = scheduler_addtask(s, task_type_drift, task_subtype_none,
-                                          0, 0, ci, NULL, 0);
-          lock_unlock_blind(&ci->lock);
-          lock_lock(&cj->lock);
-          if (cj->drift == NULL)
-            cj->drift = scheduler_addtask(s, task_type_drift, task_subtype_none,
-                                          0, 0, cj, NULL, 0);
-          lock_unlock_blind(&cj->lock);
-
           /* Otherwise, split it. */
         } else {