Hi, Yesterday I suddenly got an RCU stall on my machine. I don't know what really led to it, I just started getting "BUG: soft lockup" messages on all my terminals. Here's a small extract of what the logs show: [88989.550488] INFO: rcu_sched self-detected stall on CPU { 0} (t=5250 jiffies g=2697311 c=2697310 q=12358) [88989.550496] Task dump for CPU 0: [88989.550499] chrome R running task 0 2311 2241 0x00000108 [88989.550502] 0000000000000001 ffffffff81854ac0 ffffffff810c33a0 000000000029285f [88989.550505] ffff88031ea16500 ffffffff81854ac0 0000000000000000 ffffffff81907580 [88989.550508] ffffffff810c6501 ffff88030c7b9140 ffffffff81088d05 ffffffff81ac14c0 [88989.550510] Call Trace: [88989.550512] [] ? rcu_dump_cpu_stacks+0x80/0xb0 [88989.550522] [] ? rcu_check_callbacks+0x421/0x6e0 [88989.550525] [] ? notifier_call_chain+0x45/0x70 [88989.550528] [] ? timekeeping_update+0xf1/0x150 [88989.550531] [] ? tick_sched_handle.isra.15+0x60/0x60 [88989.550534] [] ? update_process_times+0x36/0x60 [88989.550537] [] ? tick_sched_handle.isra.15+0x60/0x60 [88989.550539] [] ? tick_sched_handle.isra.15+0x24/0x60 [88989.550542] [] ? tick_sched_handle.isra.15+0x60/0x60 [88989.550545] [] ? tick_sched_timer+0x3b/0x70 [88989.550547] [] ? __hrtimer_run_queues+0xd6/0x200 [88989.550551] [] ? read_tsc+0x5/0x10 [88989.550554] [] ? hrtimer_interrupt+0x9a/0x180 [88989.550558] [] ? smp_apic_timer_interrupt+0x39/0x50 [88989.550560] [] ? apic_timer_interrupt+0x6b/0x70 [88989.550563] [] ? del_timer+0x60/0x60 [88989.550565] [] ? del_timer_sync+0x44/0x50 [88989.550569] [] ? inet_csk_reqsk_queue_drop+0x60/0x1b0 [88989.550572] [] ? reqsk_timer_handler+0xef/0x280 [88989.550574] [] ? inet_csk_reqsk_queue_drop+0x1b0/0x1b0 [88989.550576] [] ? call_timer_fn+0x30/0xe0 [88989.550578] [] ? inet_csk_reqsk_queue_drop+0x1b0/0x1b0 [88989.550581] [] ? run_timer_softirq+0x163/0x280 [88989.550583] [] ? read_tsc+0x5/0x10 [88989.550586] [] ? __do_softirq+0xfe/0x250 [88989.550589] [] ? irq_exit+0x92/0xa0 [88989.550592] [] ? smp_apic_timer_interrupt+0x3e/0x50 [88989.550594] [] ? apic_timer_interrupt+0x6b/0x70 [88989.550595] [89008.593604] NMI watchdog: BUG: soft lockup - CPU#2 stuck for 22s! [swapper/2:0] The full log can be found here (there are lots of drm/i915 warnings too, but I think they're unrelated): http://pastebin.coelho.fi/265ebd1dcd443446.txt Has anyone else seen this? Or does anyone have a clue of what it might be? -- Cheers, Luca.{.n++%ݶw{.n+{G{ayʇڙ,jfhz_(階ݢj"mG?&~iOzv^m ?I