Re: [PATCH v5 00/45] CPU hotplug: stop_machine()-free CPU hotplug

From: Thomas Gleixner
Date: Mon Feb 18 2013 - 05:54:38 EST

On Mon, 18 Feb 2013, Srivatsa S. Bhat wrote:
> Lockup observed while running this patchset, with CPU_IDLE and INTEL_IDLE turned
> on in the .config:
> smpboot: CPU 1 is now offline
> Kernel panic - not syncing: Watchdog detected hard LOCKUP on cpu 11
> Pid: 0, comm: swapper/11 Not tainted 3.8.0-rc7+stpmch13-1 #8
> Call Trace:
> [<ffffffff812aba1e>] do_raw_spin_lock+0x7e/0x150
> [<ffffffff815a64c1>] _raw_spin_lock_irqsave+0x61/0x70
> [<ffffffff810c0758>] ? clockevents_notify+0x28/0x150
> [<ffffffff815a6d37>] ? _raw_spin_unlock_irqrestore+0x77/0x80
> [<ffffffff810c0758>] clockevents_notify+0x28/0x150
> [<ffffffff8130459f>] intel_idle+0xaf/0xe0
> [<ffffffff81472ee0>] ? disable_cpuidle+0x20/0x20
> [<ffffffff81472ef9>] cpuidle_enter+0x19/0x20
> [<ffffffff814734c1>] cpuidle_wrap_enter+0x41/0xa0
> [<ffffffff81473530>] cpuidle_enter_tk+0x10/0x20
> [<ffffffff81472f17>] cpuidle_enter_state+0x17/0x50
> [<ffffffff81473899>] cpuidle_idle_call+0xd9/0x290
> [<ffffffff810203d5>] cpu_idle+0xe5/0x140
> [<ffffffff8159c603>] start_secondary+0xdd/0xdf

> BUG: spinlock lockup suspected on CPU#2, migration/2/19
> lock: clockevents_lock+0x0/0x40, .magic: dead4ead, .owner: swapper/8/0, .owner_cpu: 8

Unfortunately there is no back trace for cpu8. That's probably caused
by the watchdog -> panic setting.

So we have no idea why cpu2 and 11 get stuck on the clockevents_lock
and without that information it's impossible to decode.



To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at