Re: 2.6.14-rc4-rt7

[Rui Nuno Capela <rncbc@rncbc.org>]

Steven Rostedt wrote:
> On Thu, 2005-10-27 at 09:01 +0100, Rui Nuno Capela wrote:
>
>
> > Don't really know if its consistent, but it does occur on several times, 
> > on only on boot.
>
>
> Rui,
>
> Have you tried the last patch that I sent John?  It may just be a race
> condition in the checking that causes a false positive.  My last patch
> fixes that.
>
> -- Steve

So far so good.

Tks.
--
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

--- linux-2.6.14-rc5-rt7.0/kernel/time/timeofday.c	2005-10-26 16:57:03.000000000 -0400
+++ linux-2.6.14-rc5-rt7.1/kernel/time/timeofday.c	2005-10-26 22:10:32.000000000 -0400
@@ -232,6 +232,12 @@
 	unsigned long seq;
 	ktime_t prev, now;
 	nsec_t mc, prev_st, curr_st;
+	unsigned long flags;
+
+	raw_local_irq_save(flags);
+	prev = per_cpu(prev_mono_time, cpu);
+	prev_st = per_cpu(prev_system_time, cpu);
+	raw_local_irq_restore(flags);
 
 	/* atomically read __get_monotonic_clock_ns() */
 	do {
@@ -242,11 +248,7 @@
 	} while (read_seqretry(&system_time_lock, seq));
 
 	ns_to_timespec(ts, mc);
-
 	now = timespec_to_ktime(*ts);
-	prev = per_cpu(prev_mono_time, cpu);
-
-	prev_st = per_cpu(prev_system_time, cpu);
 	curr_st = system_time;
 
 	if (ktime_cmp(now, <, prev)) {
@@ -264,8 +266,12 @@
 		ktime_to_timespec(ts, prev);
 		return;
 	}
+
+	raw_local_irq_save(flags);
 	per_cpu(prev_mono_time, cpu) = now;
 	per_cpu(prev_system_time, cpu) = system_time;
+	raw_local_irq_restore(flags);
+
 	put_cpu();
 }