On Thu, Apr 20, 2017 at 07:56:22PM +0200, Thomas Gleixner wrote: > On Thu, 20 Apr 2017, Frederic Weisbecker wrote: > > > So far we have run into too much troubles with the optimization path > > that skips reprogramming the clock on IRQ exit when the expiration > > deadline hasn't changed. If by accident the cached deadline happens to > > be out of sync with the hardware deadline, the buggy result and its > > cause are hard to investigate. So lets detect and warn about the issue > > early. > > > > Signed-off-by: Frederic Weisbecker <[email protected]> > > Cc: Tim Wright <[email protected]> > > Cc: Pavel Machek <[email protected]> > > Cc: James Hartsock <[email protected]> > > Cc: Peter Zijlstra <[email protected]> > > Cc: Rik van Riel <[email protected]> > > Cc: Thomas Gleixner <[email protected]> > > Cc: Ingo Molnar <[email protected]> > > --- > > kernel/time/tick-sched.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c > > index 502b320..eb1366e 100644 > > --- a/kernel/time/tick-sched.c > > +++ b/kernel/time/tick-sched.c > > @@ -783,8 +783,10 @@ static ktime_t tick_nohz_stop_sched_tick(struct > > tick_sched *ts, > > tick = expires; > > > > /* Skip reprogram of event if its not changed */ > > - if (ts->tick_stopped && (expires == ts->next_tick)) > > + if (ts->tick_stopped && (expires == ts->next_tick)) { > > + WARN_ON_ONCE(dev->next_event > ts->next_tick); > > What about handling it proper ? dev->next_event might be KTIME_MAX, > i.e. no more event for the next 500+ years.
I thought I handled this case, what I'm I missing? > Thanks, > > tglx
