Messages in this thread | | | Subject | Re: Suspend resume problem (WAS Re: [ANNOUNCE] 3.8.10-rt6) | From | Steven Rostedt <> | Date | Fri, 03 May 2013 11:31:02 -0400 |
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On Fri, 2013-05-03 at 11:59 +0200, Sebastian Andrzej Siewior wrote: > > > As the NMI dump only happens because of the time jump, which as you > > said, is -rt only, I wouldn't say that the NMI deadlock is a mainline > > bug. > > The reason for the NMI was a bug in the -RT tree but if something else > triggers that NMI we have a good chance to deadlock.
But only if the NMI does a printk(). The only reason NMIs do printks is when a bug is detected. But usually oops_in_progress() is called and also zap_locks() is suppose to help prevent these problems. But that doesn't always work.
> > What about a try_lock() and leave after 50 usecs of trying and not > getting it in the in_nmi() case?
I wouldn't try too hard to fix printks for NMIs. There's many things that can go wrong with NMIs doing a printk while another printk is active.
-- Steve
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