Re: [lkp] [x86/hpet] a28b41ab00: RIP: 0010:[<ffffffff84884ef2>] [<ffffffff84884ef2>] __lock_acquire+0xce/0x649

[Sebastian Andrzej Siewior]

* kernel test robot | 2016-07-14 10:53:20 [+0800]:

>FYI, we noticed the following commit:
>
>https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git tmp.smp/hotplug
>commit a28b41ab00dc93b9b16deda9d9b4b26601444f6d ("x86/hpet: Convert to hotplug state machine")

This is gone in the meantime. I have head
ecd8081f6fb9032c41e5c38885f06836da6ab455 of WIP.hotplug. The commit in
question is in as 48d7f6c71578 ("x86/hpet: Convert to hotplug state
machine").

>in testcase: boot
>
>on test machine: 2 threads qemu-system-x86_64 -enable-kvm -cpu Nehalem with 320M memory
>
>caused below changes:
â

>[    1.659021] Unpacking initramfs...
>[    1.696928] workqueue: round-robin CPU selection forced, expect performance impact
>[    1.702995] general protection fault: 0000 [#1]
>[    1.704143] Modules linked in:
>[    1.704950] CPU: 0 PID: 1 Comm: swapper Not tainted 4.7.0-rc7-00193-ga28b41a #1
>[    1.709158] task: ffff880012052000 ti: ffff880012054000 task.ti: ffff880012054000
>[    1.713142] RIP: 0010:[<ffffffff84884ef2>]  [<ffffffff84884ef2>] __lock_acquire+0xce/0x649

The tree I mentioned boots, I get pass this point and am in
|[   64.481048] rcu-torture: Reader Pipe:  2 0 0 0 0 0 0 0 0 0 0

so you might have tested a stale version of the patch queue.

Sebastian