Re: [5/6] 2.6.21-rc2: known regressions

Thomas Gleixner
2007-03-06T00:19:53Z

On Mon, 2007-03-05 at 15:45 -0800, Linus Torvalds wrote:
>
> On Tue, 6 Mar 2007, Thomas Gleixner wrote:
> > >
> > > Subject : macbook pro suspend to ram broken (clockevents)
> > > References : http://lkml.org/lkml/2007/3/4/110
> > > Submitter : Soeren Sonnenburg <kernel@nn7.de>
> > > Caused-By : Thomas Gleixner <tglx@linutronix.de>
> > > commit e9e2cdb412412326c4827fc78ba27f410d837e6e
> > > Status : unknown
> >
> > I can reproduce this on my dual core VAIO. There are some issues:
>
> Yeah, I think I can too, on my dual-core Mac Mini.
>
> I'm not done with my bisection, but e9e2cdb4 is among the 28 commits left,
> so I'm pretty sure I'm hitting the same bug. I'll do a few more bootups to
> be 100% sure.

I just got the resume fix cleaned up. The suspend / resume thing was
dropped unintentionally during the -mm code reshuffling.

It still needs the broadcast fix though.

Does this make the problem go away ?

tglx

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 12b3efe..5567745 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -284,6 +284,42 @@ void tick_shutdown_broadcast(unsigned int *cpup)
spin_unlock_irqrestore(&tick_broadcast_lock, flags);
}

+void tick_suspend_broadcast(void)
+{
+ struct clock_event_device *bc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+ bc = tick_broadcast_device.evtdev;
+ if (bc && tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
+ clockevents_set_mode(bc, CLOCK_EVT_MODE_SHUTDOWN);
+
+ spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+}
+
+int tick_resume_broadcast(void)
+{
+ struct clock_event_device *bc;
+ unsigned long flags;
+ int broadcast = 0;
+
+ spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+ bc = tick_broadcast_device.evtdev;
+ if (bc) {
+ if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC &&
+ !cpus_empty(tick_broadcast_mask))
+ tick_broadcast_start_periodic(bc);
+
+ broadcast = cpu_isset(smp_processor_id(), tick_broadcast_mask);
+ }
+ spin_unlock_irqrestore(&tick_broadcast_lock, flags);
+
+ return broadcast;
+}
+
+
#ifdef CONFIG_TICK_ONESHOT

static cpumask_t tick_broadcast_oneshot_mask;
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 0986a2b..43ba1bd 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -298,6 +298,28 @@ static void tick_shutdown(unsigned int *cpup)
spin_unlock_irqrestore(&tick_device_lock, flags);
}

+static void tick_suspend_periodic(void)
+{
+ struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tick_device_lock, flags);
+ if (td->mode == TICKDEV_MODE_PERIODIC)
+ clockevents_set_mode(td->evtdev, CLOCK_EVT_MODE_SHUTDOWN);
+ spin_unlock_irqrestore(&tick_device_lock, flags);
+}
+
+static void tick_resume_periodic(void)
+{
+ struct tick_device *td = &__get_cpu_var(tick_cpu_device);
+ unsigned long flags;
+
+ spin_lock_irqsave(&tick_device_lock, flags);
+ if (td->mode == TICKDEV_MODE_PERIODIC)
+ tick_setup_periodic(td->evtdev, 0);
+ spin_unlock_irqrestore(&tick_device_lock, flags);
+}
+
/*
* Notification about clock event devices
*/
@@ -325,6 +347,16 @@ static int tick_notify(struct notifier_block *nb, unsigned long reason,
tick_shutdown(dev);
break;

+ case CLOCK_EVT_NOTIFY_SUSPEND:
+ tick_suspend_periodic();
+ tick_suspend_broadcast();
+ break;
+
+ case CLOCK_EVT_NOTIFY_RESUME:
+ if (!tick_resume_broadcast())
+ tick_resume_periodic();
+ break;
+
default:
break;
}
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 54861a0..75890ef 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -67,6 +67,8 @@ extern int tick_check_broadcast_device(struct clock_event_device *dev);
extern int tick_is_broadcast_device(struct clock_event_device *dev);
extern void tick_broadcast_on_off(unsigned long reason, int *oncpu);
extern void tick_shutdown_broadcast(unsigned int *cpup);
+extern void tick_suspend_broadcast(void);
+extern int tick_resume_broadcast(void);

extern void
tick_set_periodic_handler(struct clock_event_device *dev, int broadcast);
@@ -90,6 +92,8 @@ static inline int tick_device_uses_broadcast(struct clock_event_device *dev,
static inline void tick_do_periodic_broadcast(struct clock_event_device *d) { }
static inline void tick_broadcast_on_off(unsigned long reason, int *oncpu) { }
static inline void tick_shutdown_broadcast(unsigned int *cpup) { }
+static inline void tick_suspend_broadcast(void) { }
+static inline int tick_resume_broadcast(void) { return 0; }

/*
* Set the periodic handler in non broadcast mode
diff --git a/kernel/timer.c b/kernel/timer.c
index 6663a87..718437f 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -997,6 +997,9 @@ static int timekeeping_resume(struct sys_device *dev)
write_sequnlock_irqrestore(&xtime_lock, flags);

touch_softlockup_watchdog();
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
+
/* Resume hrtimers */
clock_was_set();

@@ -1011,6 +1014,9 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
timekeeping_suspended = 1;
timekeeping_suspend_time = read_persistent_clock();
write_sequnlock_irqrestore(&xtime_lock, flags);
+
+ clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
+
return 0;
}