Messages in this thread | | | Date | Fri, 03 May 2013 11:59:32 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: Suspend resume problem (WAS Re: [ANNOUNCE] 3.8.10-rt6) |
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On 04/30/2013 08:08 PM, Steven Rostedt wrote: >> This NMI releated deadlock is a problem which should also trigger >> mainline, right? > > Well, yeah, as sending out a NMI stack dump is sorta the last resort, > and is dangerous to do printks from NMI context.
So we did bad and we upgrade to bad and dangerous.
>> >> Now, the time jump on the other hand is the real issue here and is >> RT-only. It looks like we get a big number of timer updates via >> tick_do_update_jiffies64() because according to ktime_get() that much >> time really passed by. > > 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.
What about a try_lock() and leave after 50 usecs of trying and not getting it in the in_nmi() case?
> -- Steve
Sebastian
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