On Thu, Jul 11, 2013 at 12:07:21PM +0200, Borislav Petkov wrote: > On Thu, Jul 11, 2013 at 11:38:37AM +0200, Rolf Eike Beer wrote: > > Hi, > > > > I'm running 3.10.0 (from openSUSE packages) on an "Intel(R) Core(TM) > > i7-2600 > > CPU @ 3.40GHz". I got a hard lockup on one of my CPUs twice, once with > > backtrace (see attached image). Graphics is the builtin Intel, used with X > > 7.6 > > and KDE 4.10beta2 (basically current openSUSE 12.3+KDE). > > > > I'm not aware that I had done anything special, just "normal" desktop and > > development usage, but no heavy compile work at the moment the lockups > > happened. > > Hmm, I can see commit_creds() doing some rcu pointers assignment and rcu > calling into the scheduler which screams about a cpu runqueue of the > task we're about to reschedule not being locked. Let's add some more > people who should know better.
Ok, for the other people too lazy to bother finding the picture: http://marc.info/?l=linux-kernel&m=137353587012001&q=p3 So we bug at: kernel/sched/core.c:519 assert_raw_spin_locked(&task_rq(p)->lock); and get there through: resched_task() check_preempt_wakeup() check_preempt_curr() try_to_wake_up() autoremove_wake_function() __call_rcu_nocb_enqueue() __call_rcu() commit_creds() ____call_usermodehelper() ret_from_fork() That don't make much sense though. Since: try_to_wake_up() ttwu_queue() raw_spin_lock(&rq->lock) ttwu_do_activate() ttwu_do_wakeup() check_preempt_curr() check_preempt_wakeup() resched_task(rq->curr) assert_raw_spin_locked(task_rq(p)->lock) It would somehow mean that 'task_rq(rq->curr) != rq', that's completely bonkers, we do after all have rq->lock locked. I must also say that I've _never_ seen this bug before. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
