On 07/25/2011 03:20 PM, Darren Hart wrote:

On 07/24/2011 09:12 AM, Thomas Gleixner wrote:

quoted

On Sun, 24 Jul 2011, Maarten Lankhorst wrote:

...

quoted

quoted

Also not sure where this one came from:
[   37.456688] BUG: spinlock bad magic on CPU#3, threaded-ml/1619
[   37.456690]  lock: ffff8801fdc74d50, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
[   37.456692] Pid: 1619, comm: threaded-ml Tainted: G         C  3.0.0-rt3-patser+ #39
[   37.456693] Call Trace:
[   37.456697]  [<ffffffff81607a78>] spin_bug+0xa0/0xa8
[   37.456699]  [<ffffffff8132b412>] do_raw_spin_lock+0xa2/0x170
[   37.456702]  [<ffffffff8104a201>] ? get_parent_ip+0x11/0x50
[   37.456704]  [<ffffffff8160d783>] _raw_spin_lock+0x23/0x30
[   37.456706]  [<ffffffff810931ce>] rt_mutex_start_proxy_lock+0x2e/0xd0
[   37.456708]  [<ffffffff8109093a>] futex_requeue+0x47a/0x850
[   37.456710]  [<ffffffff8109138e>] do_futex+0xae/0xb00
[   37.456712]  [<ffffffff81157dcd>] ? fget_light+0x6d/0x110
[   37.456714]  [<ffffffff810b77b7>] ? audit_syscall_entry+0x2e7/0x310
[   37.456715]  [<ffffffff814c9375>] ? sys_recvmsg+0x75/0x90
[   37.456717]  [<ffffffff810923e6>] compat_sys_futex+0xf6/0x190
[   37.456719]  [<ffffffff8100e864>] ? syscall_trace_enter+0x184/0x210
[   37.456721]  [<ffffffff816158b3>] ia32_do_call+0x13/0x13

Urrgh, that's not a good one. Darren, can you please have a look at that?

Will do.

Maarten, what are you running when you hit this?
rt_mutex_start_proxy_lock() is only called by the requeue_pi code and
there is no libc support for that yet, so I'm surprised to see that in
the stack trace (unless you're running my futextest suite).

I've run a couple iterations of functional/run.sh from futextest which
exercises the requeue_pi code with no errors. I also wrote a new test to
improperly use the requeue_pi path, and the kernel properly detects the
abuse and kicks the user back with -EINVAL.

Could you try running futextest on your system to see if you can
reproduce the above? Specifically the functional/run.sh script (no need
to run the performance bits).

http://git.kernel.org/?p=linux/kernel/git/dvhart/futextest.git;a=summary

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel