On Fri, 2014-01-17 at 18:14 +0100, Sebastian Andrzej Siewior wrote: 

* Mike Galbraith | 2013-12-25 18:37:37 [+0100]:

quoted

On Tue, 2013-12-24 at 23:55 -0800, Paul E. McKenney wrote: 

quoted

On Wed, Dec 25, 2013 at 04:07:34AM +0100, Mike Galbraith wrote:

Having sufficiently recovered from turkey overdose to be able to slither
upstairs (bump bump bump) to check on the box, commenting..

# timers-do-not-raise-softirq-unconditionally.patch
# rtmutex-use-a-trylock-for-waiter-lock-in-trylock.patch

..those two out does seem to have stabilized the thing.

timers-do-not-raise-softirq-unconditionally.patch is on its way out.

rtmutex-use-a-trylock-for-waiter-lock-in-trylock.patch confues me.
Didn't you report once that your box deadlocks without this patch? Now
your 64way box on the other hand does not work with it?

If 'do not raise' is applied, 'use a trylock' won't save you.  If 'do
not raise' is not applied, _and_ you wisely do not try to turn on very
expensive nohz_full, things work fine without 'use a trylock'.

-Mike