Re: [BUG] sched: clock wrap bug in 2.6.35-stable kills scheduling

[Peter Zijlstra <peterz@infradead.org>]

On Mon, 2012-06-25 at 11:45 +0200, Peter Zijlstra wrote:
> On Sun, 2012-06-24 at 19:32 +0200, Thomas Lange wrote:
> > Bug was introduced in 2.6.35.12 and is still present in linux-2.6.35.y HEAD.
> 
> Ok, so nobody cares about that.. what does something recent like 3.5-rc4
> do?
> 
> If that's fixed, find the patch that fixes it. If not, we'll have a
> look.


If anything, I think something like the below ought to cure things.

---
 kernel/sched/clock.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c
index c685e31..a1a128a 100644
--- a/kernel/sched/clock.c
+++ b/kernel/sched/clock.c
@@ -74,7 +74,7 @@
  */
 unsigned long long __attribute__((weak)) sched_clock(void)
 {
-	return (unsigned long long)(jiffies - INITIAL_JIFFIES)
+	return (unsigned long long)(get_jiffies_64() - INITIAL_JIFFIES)
 					* (NSEC_PER_SEC / HZ);
 }
 EXPORT_SYMBOL_GPL(sched_clock);