From bed1c0d42e166b62c9eedcd85062fc64512f50b2 Mon Sep 17 00:00:00 2001
From: Stefano Ceccherini <stefano.ceccherini@gmail.com>
Date: Mon, 21 Sep 2009 09:49:41 +0000
Subject: [PATCH] Sort timers by priority before initializing them, so we avoid
 initializing timers which we will never use.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@33218 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 src/system/kernel/arch/x86/arch_timer.c | 51 ++++++++++++++++---------
 1 file changed, 34 insertions(+), 17 deletions(-)

diff --git a/src/system/kernel/arch/x86/arch_timer.c b/src/system/kernel/arch/x86/arch_timer.c
index 4f43360317..035b7487bd 100644
--- a/src/system/kernel/arch/x86/arch_timer.c
+++ b/src/system/kernel/arch/x86/arch_timer.c
@@ -62,34 +62,51 @@ arch_timer_clear_hardware_timer(void)
 }
 
 
+static void
+sort_timers(timer_info *timers[], int numTimers)
+{
+	int size;
+	timer_info *tempPtr;
+	int max = 0;	
+	int i = 0;
+	
+	for (size = numTimers; size > 1; size--) {
+		for (i = 0; i < size; i++) {
+			if (timers[i]->get_priority() > timers[max]->get_priority())
+				max = i;
+		}
+		tempPtr = timers[max];
+		timers[max] = timers[size - 1];
+		timers[size - 1] = tempPtr;		
+	}
+#if 0
+	for (i = 0; i < numTimers; i++) {
+		dprintf("timer[%d]: prio %d\n", i, timers[i]->get_priority());
+	}
+#endif
+}
+
+
 int
 arch_init_timer(kernel_args *args)
 {
 	int i = 0;
-	int bestPriority = -1;
 	timer_info *timer = NULL;
-	cpu_status state = disable_interrupts();
+	cpu_status state;
+
+	sort_timers(sTimers, (sizeof(sTimers) / sizeof(sTimers[0])) - 1);
+
+	state = disable_interrupts();
 
 	for (i = 0; (timer = sTimers[i]) != NULL; i++) {
-		int priority = timer->get_priority();
-
-		if (priority < bestPriority) {
-			TRACE(("arch_init_timer: Skipping %s because there is a higher priority timer (%s) initialized.\n", timer->name, sTimer->name));
-			continue;
-		}
-
-		if (timer->init(args) != B_OK) {
+		if (timer->init(args) == B_OK) {
 			TRACE(("arch_init_timer: %s failed init. Skipping.\n", timer->name));
-			continue;
-		}
-
-		if (priority > bestPriority) {
-			bestPriority = priority;
-			sTimer = timer;
-			TRACE(("arch_init_timer: %s is now best timer module with prio %d.\n", timer->name, bestPriority));
+			break;
 		}
 	}
 
+	sTimer = timer;
+
 	if (sTimer != NULL) {
 		dprintf("arch_init_timer: using %s timer.\n", sTimer->name);
 	} else {