From e67116354084dcf587c03dccaeb18d8cee886c1b Mon Sep 17 00:00:00 2001
From: Andre Noll <maan@systemlinux.org>
Date: Wed, 16 Jun 2010 22:39:57 +0200
Subject: [PATCH] sched: Add debug mode.

This adds the compile-time switch SCHED_DEBUG to activate debug
mode for the scheduler. If activated, it measures the time spent in
each post_select() function and prints warning messages if this time
interval is too large.

This patch has no effect if SCHED_DEBUG is not set.
---
 sched.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/sched.c b/sched.c
index 62d45d52..f703890b 100644
--- a/sched.c
+++ b/sched.c
@@ -17,6 +17,7 @@
 #include "list.h"
 #include "sched.h"
 #include "string.h"
+#include "time.h"
 #include "error.h"
 
 static struct list_head pre_select_list, post_select_list;
@@ -68,13 +69,33 @@ static void sched_preselect(struct sched *s)
 	}
 }
 
+#define SCHED_DEBUG 0
+static inline void call_post_select(struct sched *s, struct task *t)
+{
+#ifndef SCHED_DEBUG
+	t->post_select(s, t);
+#else
+	struct timeval t1, t2, diff;
+	unsigned long pst;
+
+	gettimeofday(&t1, NULL);
+	t->post_select(s, t);
+	gettimeofday(&t2, NULL);
+	tv_diff(&t1, &t2, &diff);
+	pst = tv2ms(&diff);
+	if (pst > 50)
+		PARA_WARNING_LOG("%s: post_select time: %lums\n",
+			t->status, pst);
+#endif
+}
+
 static void sched_post_select(struct sched *s)
 {
 	struct task *t, *tmp;
 
 	list_for_each_entry_safe(t, tmp, &post_select_list, post_select_node) {
 		if (t->error >= 0)
-			t->post_select(s, t);
+			call_post_select(s, t);
 //		PARA_INFO_LOG("%s: %d\n", t->status, t->ret);
 		if (t->error >= 0)
 			continue;
-- 
2.39.2