[ 1963.297730] Kernel panic - not syncing: Timeout: Not all CPUs entered broadcast exception handler
[ 1963.297803] ===============================
[ 1963.297831] [ INFO: suspicious RCU usage. ]
[ 1963.297860] 4.2.0-rc2+ #47 Tainted: G        W   E  
[ 1963.297889] -------------------------------
[ 1963.297918] include/linux/rcupdate.h:849 rcu_read_lock() used illegally while idle!
[ 1963.297949] 
[ 1963.297949] other info that might help us debug this:
[ 1963.297949] 
[ 1963.297984] 
[ 1963.297984] RCU used illegally from idle CPU!
[ 1963.297984] rcu_scheduler_active = 1, debug_locks = 0
[ 1963.298019] RCU used illegally from extended quiescent state!
[ 1963.298047] 1 lock held by swapper/1/0:
[ 1963.298074]  #0:  (rcu_read_lock){......}, at: [<ffffffff810abd75>] atomic_notifier_call_chain+0x5/0x110
[ 1963.298229] 
[ 1963.298229] stack backtrace:
[ 1963.298260] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W   E   4.2.0-rc2+ #47
[ 1963.298292] Hardware name: Intel Corporation Skylake Client platform/Skylake Y LPDDR3 RVP3, BIOS SKLSE2R1.R00.B084.B00.1505120313 05/12/2015
[ 1963.298329]  0000000000000001 ffff88016e243f08 ffffffff8184a1bb 0000000000000011
[ 1963.298463]  ffff880168e70000 ffff88016e243f38 ffffffff810dc2d7 ffffffff81e1e1c0
[ 1963.298598]  0000000000000002 0000000000000000 ffff88016e248f58 ffff88016e243f78
[ 1963.298731] Call Trace:
[ 1963.298760]  <IRQ>  [<ffffffff8184a1bb>] dump_stack+0x4c/0x65
[ 1963.298825]  [<ffffffff810dc2d7>] lockdep_rcu_suspicious+0xe7/0x120
[ 1963.298860]  [<ffffffff810abe46>] atomic_notifier_call_chain+0xd6/0x110
[ 1963.298894]  [<ffffffff810abd75>] ? atomic_notifier_call_chain+0x5/0x110
[ 1963.298929]  [<ffffffff810da96d>] ? trace_hardirqs_off+0xd/0x10
[ 1963.298964]  [<ffffffff8102844f>] exit_idle+0x3f/0x50
[ 1963.298997]  [<ffffffff818574dc>] smp_apic_timer_interrupt+0x3c/0x60
[ 1963.299031]  [<ffffffff81855510>] apic_timer_interrupt+0x70/0x80
[ 1963.299063]  <EOI>  <#MC>