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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
