From: Andre Noll <maan@systemlinux.org>
Date: Thu, 21 Jul 2011 17:39:03 +0000 (+0200)
Subject: sched: Kill unnecessary check in sched_pre_select().
X-Git-Tag: v0.4.8~11^2~1
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=7544e25415144894b58e48ab17de21a693ea00c7;ds=sidebyside

sched: Kill unnecessary check in sched_pre_select().

The only two callers of sched_shutdown() call this function
from post_select context, so we may safely remove the check
whether the pre_select list is empty.

Add a comment to sched_shutdown() which mentions that this
function must be called from post_select.
---

diff --git a/sched.c b/sched.c
index 8648811d..7b5ca63d 100644
--- a/sched.c
+++ b/sched.c
@@ -52,18 +52,8 @@ static void sched_preselect(struct sched *s)
 	list_for_each_entry_safe(t, tmp, &pre_select_list, pre_select_node) {
 		if (t->pre_select)
 			t->pre_select(s, t);
-//		PARA_INFO_LOG("%s \n", t->status);
-		if (t->error >= 0)
-			continue;
-		/*
-		 * We have to check whether the list is empty because the call
-		 * to ->pre_select() might have called sched_shutdown(). In
-		 * this case t has been unregistered already, so we must not
-		 * unregister it again.
-		 */
-		if (list_empty(&pre_select_list))
-			return;
-		unregister_task(t);
+		if (t->error < 0)
+			unregister_task(t);
 	}
 }
 
@@ -97,7 +87,12 @@ static void sched_post_select(struct sched *s)
 //		PARA_INFO_LOG("%s: %d\n", t->status, t->ret);
 		if (t->error >= 0)
 			continue;
-		/* nec., see sched_preselect() */
+		/*
+		 * We have to check whether the list is empty because the call
+		 * to ->post_select() might have called sched_shutdown(). In
+		 * this case t has been unregistered already, so we must not
+		 * unregister it again.
+		 */
 		if (list_empty(&post_select_list))
 			return;
 		unregister_task(t);
@@ -197,7 +192,8 @@ void register_task(struct task *t)
  * Unregister all tasks.
  *
  * This will cause \a schedule() to return immediately because both the
- * \a pre_select_list and the \a post_select_list are empty.
+ * \a pre_select_list and the \a post_select_list are empty. This function
+ * must be called from the post_select (rather than the pre_select) method.
  */
 void sched_shutdown(void)
 {