On 05/12/2014 12:28 PM, Jan Kara wrote: > On Wed 07-05-14 22:03:08, Sasha Levin wrote: >> > Hi all, >> > >> > While fuzzing with trinity inside a KVM tools guest running the latest -next >> > kernel I've stumbled on the following spew: > Thanks for report. So the problem seems to be maginally valid but I'm not > 100% sure whom to blame :). So printk() code calls up() which calls > try_to_wake_up() under console_sem.lock spinlock. That function can take > rq->lock which is all expected. > > The next part of the chain is that during CPU initialization we call > __sched_fork() with rq->lock which calls into hrtimer_init() which can > allocate memory which creates a dependency rq->lock => zone.lock.rlock. > > And memory management code calls printk() which zone.lock.rlock held which > closes the loop. Now I suspect the second link in the chain can happen only > while CPU is booting and might even happen only if some debug options are > enabled. But I don't really know scheduler code well enough. Steven? I've cc'ed Peter and Ingo who may be able to answer that, as it still happens on -next. Thanks, Sasha -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>