| Date | Fri, 20 Feb 2015 19:56:17 -0500 (EST) | From | Nicolas Pitre <> | Subject | Re: [PATCH 27/35] sched/idle: Use explicit broadcast oneshot control function |
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On Mon, 16 Feb 2015, Peter Zijlstra wrote:
> From: Thomas Gleixner <tglx@linutronix.de> > > Replace the clockevents_notify() call with an explicit function call. > > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This patch makes my test system hang solid after letting it sit idle for 5 to 15 minutes. Reverting it and this issue goes away.
The explicit function call is not an equivalent replacement. In clockevents_notify() the clockevents_lock is held across the call to tick_broadcast_enter() or tick_broadcast_exit(). This patch drops the locking.
> --- > kernel/sched/idle.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > Index: linux/kernel/sched/idle.c > =================================================================== > --- linux.orig/kernel/sched/idle.c > +++ linux/kernel/sched/idle.c > @@ -143,8 +143,7 @@ use_default: > * is used from another cpu as a broadcast timer, this call may > * fail if it is not available > */ > - if (broadcast && > - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu)) > + if (broadcast && tick_broadcast_enter()) > goto use_default; > > /* Take note of the planned idle state. */ > @@ -161,7 +160,7 @@ use_default: > idle_set_state(this_rq(), NULL); > > if (broadcast) > - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); > + tick_broadcast_exit(); > > /* > * Give the governor an opportunity to reflect on the outcome > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > >
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