On Sunday, 11 March 2007 21:57, Milan Broz wrote: > Thomas Meyer napsal(a): > > Rafael J. Wysocki schrieb: > >> On Sunday, 11 March 2007 21:23, Milan Broz wrote: > >> > >>> Rafael J. Wysocki: > >>> > >>>> Ah, NO_HZ. Thomas Gleixner's address added to the Cc list. > >>>> > >>>> > >>>>> short printk trace > >>>>> > >>>>> enable_nonboot_cpus > >>>>> _cpu_up > >>>>> raw_notifier_callchain (CPU_UP_PREPARE) > >>>>> ... > >>>>> update_sched_domains > >>>>> detach_destroy_domains > >>>>> [waits here] --> synchronize_sched (==synchronize_rcu) > >>>>> > >>>> Well, I think the call to wait_for_completion() does not return, probably > >>>> because the task supposed to complete the completion is frozen at this > >>>> point. Can you please try to confirm that it gets stuck on > >>>> wait_for_completion() in synchronize_rcu()? > >>>> > >>> Yes, it's in wait_for_completion() in synchronize_rcu(). > >>> As noted in some previous mail, it will wake up after > >>> event - key press etc. > >>> > >>> Patch in http://lkml.org/lkml/2007/3/7/255 solves different problem. > >>> I added it to my quilt and applied anyway -> no change. > >>> > >> Does the problem go away if NO_HZ is unset? > >> > > > > i tried to boot with nohz=off, but the problem did persist. > > Hmmmm, both variants (nohz=off or recompiled kernel without NO_HZ) works for > me.
Definitely something strange is going on here. I think we need an advice from someone who knows the RCU internals. Andrew, could you please tell me whom I should ask? Rafael - 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/