[patch 26/29] softlockup: use cpu_clock() instead of sched_clock()

[Greg Kroah-Hartman <gregkh@suse.de>]

2.6.23-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: Ingo Molnar <mingo@elte.hu>

patch a3b13c23f186ecb57204580cc1f2dbe9c284953a in mainline.

sched_clock() is not a reliable time-source, use cpu_clock() instead.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 kernel/softlockup.c |   10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

--- a/kernel/softlockup.c
+++ b/kernel/softlockup.c
@@ -43,14 +43,16 @@ static struct notifier_block panic_block
  * resolution, and we don't need to waste time with a big divide when
  * 2^30ns == 1.074s.
  */
-static unsigned long get_timestamp(void)
+static unsigned long get_timestamp(int this_cpu)
 {
-	return sched_clock() >> 30;  /* 2^30 ~= 10^9 */
+	return cpu_clock(this_cpu) >> 30;  /* 2^30 ~= 10^9 */
 }
 
 void touch_softlockup_watchdog(void)
 {
-	__raw_get_cpu_var(touch_timestamp) = get_timestamp();
+	int this_cpu = raw_smp_processor_id();
+
+	__raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu);
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -96,7 +98,7 @@ void softlockup_tick(void)
 		return;
 	}
 
-	now = get_timestamp();
+	now = get_timestamp(this_cpu);
 
 	/* Wake up the high-prio watchdog task every second: */
 	if (now > (touch_timestamp + 1))

-- 
-
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