On Sat, Jul 07, 2007 at 05:10:54PM +0200, Patrick McHardy wrote: > On Sat, 7 Jul 2007, Ranko Zivojnovic wrote: > > >>On Fri, 2007-07-06 at 16:21 +0200, Patrick McHardy wrote: > >>>There is at least one ABBA deadlock, est_timer does: > >>> > >>>read_lock(&est_lock) > >>>spin_lock(e->stats_lock) (which is dev->queue_lock) > >>> > >>>and qdisc_destroy calls htb_destroy under dev->queue_lock, which > >>>calls htb_destroy_class, then gen_kill_estimator and this > >>>write_locks est_lock. > >>> > >>>I can't see the problem above though, the qdisc_run path only takes > >>>dev->queue_lock. Please enable lockdep and post the output if any. > >> > > > >I've got both code paths this time. It shows exactly the ABBA deadlock > >you describe above. The details are below. > > > Thanks. I'm still wondering whats causing the other lockup > you're seeing. > > >Maybe the appropriate way to fix this would to call gen_kill_estimator, > >with the appropriate lock order, before the call to qdisc_destroy, so > >when dev->queue_lock is taken for qdisc_destroy - the structure is > >already off the list. > > > Probably easier to just kill est_lock and use rcu lists. > I'm currently travelling, I'll look into it tomorrow. >
Congratulations to both of you! Ranko, it looks like you have some licence to kill! (I hope bugs only...) Cheers, Jarek P. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
