Hi all, I got the following spew while booting. My VM proceeded to hang and die.
[ 16.620530] ============================================= [ 16.621059] [ INFO: possible recursive locking detected ] [ 16.622024] 3.14.0-next-20140403-sasha-00019-g7474aa9-dirty #376 Not tainted [ 16.624145] --------------------------------------------- [ 16.625261] kworker/0:1/1069 is trying to acquire lock: [ 16.626300] ((&(&kobj->release)->work)){+.+.+.}, at: flush_work (kernel/workqueue.c:2880) [ 16.628258] [ 16.628258] but task is already holding lock: [ 16.629415] ((&(&kobj->release)->work)){+.+.+.}, at: process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 16.630106] [ 16.630106] other info that might help us debug this: [ 16.630106] Possible unsafe locking scenario: [ 16.630106] [ 16.630106] CPU0 [ 16.630106] ---- [ 16.630106] lock((&(&kobj->release)->work)); [ 16.630106] lock((&(&kobj->release)->work)); [ 16.630106] [ 16.630106] *** DEADLOCK *** [ 16.630106] [ 16.630106] May be due to missing lock nesting notation [ 16.630106] [ 16.630106] 2 locks held by kworker/0:1/1069: [ 16.630106] #0: ("events"){.+.+.+}, at: process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 16.630106] #1: ((&(&kobj->release)->work)){+.+.+.}, at: process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 16.630106] [ 16.630106] stack backtrace: [ 16.630106] CPU: 0 PID: 1069 Comm: kworker/0:1 Not tainted 3.14.0-next-20140403-sasha-00019-g7474aa9-dirty #376 [ 16.630106] Workqueue: events kobject_delayed_cleanup [ 16.630106] ffffffffb59d09d0 ffff88007c6a58d8 ffffffffb24bfb2f 0000000000000000 [ 16.630106] ffffffffb59d09d0 ffff88007c6a59d8 ffffffffaf1c4c8a ffff88007c5a3d98 [ 16.630106] ffff88007c5a3000 ffff880000000001 ffffffffaf1c0e18 ffff88007c5a3d60 [ 16.630106] Call Trace: [ 16.630106] dump_stack (lib/dump_stack.c:52) [ 16.630106] __lock_acquire (kernel/locking/lockdep.c:1740 kernel/locking/lockdep.c:1783 kernel/locking/lockdep.c:2115 kernel/locking/lockdep.c:3182) [ 16.630106] ? check_irq_usage (kernel/locking/lockdep.c:1638) [ 16.630106] ? __lock_acquire (kernel/locking/lockdep.c:3189) [ 16.630106] lock_acquire (arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602) [ 16.630106] ? flush_work (kernel/workqueue.c:2880) [ 16.630106] flush_work (kernel/workqueue.c:2884) [ 16.630106] ? flush_work (kernel/workqueue.c:2880) [ 16.630106] ? debug_smp_processor_id (lib/smp_processor_id.c:57) [ 16.630106] ? put_lock_stats.isra.12 (arch/x86/include/asm/preempt.h:98 kernel/locking/lockdep.c:254) [ 16.630106] ? try_to_grab_pending (kernel/workqueue.c:1260 kernel/workqueue.c:1259) [ 16.630106] ? __cancel_work_timer (arch/x86/include/asm/paravirt.h:809 (discriminator 2) kernel/workqueue.c:2913 (discriminator 2)) [ 16.630106] ? __this_cpu_preempt_check (lib/smp_processor_id.c:63) [ 16.630106] __cancel_work_timer (arch/x86/include/asm/bitops.h:313 kernel/workqueue.c:610 kernel/workqueue.c:644 kernel/workqueue.c:2916) [ 16.630106] cancel_work_sync (kernel/workqueue.c:2941) [ 16.630106] work_fixup_free (kernel/workqueue.c:479) [ 16.630106] __debug_check_no_obj_freed (lib/debugobjects.c:277 lib/debugobjects.c:700) [ 16.630106] debug_check_no_obj_freed (lib/debugobjects.c:726) [ 16.630106] kfree (mm/slub.c:2679 mm/slub.c:3401) [ 16.630106] ? rtc_device_release (drivers/rtc/class.c:35) [ 16.630106] rtc_device_release (drivers/rtc/class.c:35) [ 16.630106] device_release (drivers/base/core.c:246) [ 16.630106] kobject_delayed_cleanup (lib/kobject.c:629 lib/kobject.c:638) [ 16.630106] process_one_work (kernel/workqueue.c:2221 include/linux/jump_label.h:105 include/trace/events/workqueue.h:111 kernel/workqueue.c:2226) [ 16.630106] ? process_one_work (include/linux/workqueue.h:186 kernel/workqueue.c:611 kernel/workqueue.c:638 kernel/workqueue.c:2214) [ 16.630106] worker_thread (kernel/workqueue.c:2348) [ 16.630106] ? rescuer_thread (kernel/workqueue.c:2297) [ 16.630106] kthread (kernel/kthread.c:219) [ 16.630106] ? kthread_create_on_node (kernel/kthread.c:185) [ 16.630106] ret_from_fork (arch/x86/kernel/entry_64.S:555) [ 16.630106] ? kthread_create_on_node (kernel/kthread.c:185) Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/