Re: rtmutex assert failure (was [Patch] restore the RCU callback...)

["Robert Crocombe" <rcrocomb@gmail.com>]

On 8/25/06, Robert Crocombe <rcrocomb@gmail.com> wrote:
> Drat, this isn't quite true.  There was one attempt with 'make', and
> that produced the 1st BUG, but the latter three attempts were with
> 'make -j40': two were okay, and one produced the two BUGs.  Apologies.
>  I will make additional attempts with 'make' only.

Well, I was just doing that, and I got this:

----------- [cut here ] --------- [please bite here ] ---------
Kernel BUG at kernel/rtmutex.c:639
invalid opcode: 0000 [1] PREEMPT
CPU 0
Modules linked in: tg3
Pid: 7332, comm: ld Not tainted 2.6.17-rt8_UP_00 #3
RIP: 0010:[<ffffffff8025e89e>] <ffffffff8025e89e>{rt_lock_slowlock+209}
RSP: 0018:ffff8107ed70f9f8  EFLAGS: 00010246
RAX: ffff8107f2b13540 RBX: ffffffff804aa510 RCX: ffffffff804aacc0
RDX: ffff8107f2b13540 RSI: ffff8107ed70f9e8 RDI: ffffffff804aa510
RBP: ffff8107ed70fab8 R08: 0000000000000000 R09: ffff8107ed70f9f8
R10: 0000000000000002 R11: ffff8107fdcd8080 R12: ffff81001cbe3ad0
R13: 0000000000000000 R14: ffffffff8029a81b R15: 0000000000000001
FS:  00002b9a0c7e0d50(0000) GS:ffffffff805fe000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00000000005b9e5c CR3: 00000007eb86e000 CR4: 00000000000006e0
Process ld (pid: 7332, threadinfo ffff8107ed70e000, task ffff8107f2b13540)
Stack: 111111110000008c ffff8107ed70fa00 ffff8107ed70fa00 ffff8107ed70fa10
       ffff8107ed70fa10 0000000000000000 111111110000008c ffff8107ed70fa30
       ffff8107ed70fa30 ffff8107ed70fa40
Call Trace:
       <ffffffff8025f4b8>{rt_lock+13}
       <ffffffff8029a81b>{free_pages_bulk+42}
       <ffffffff8029abf7>{__free_pages_ok+438}
       <ffffffff8022c07e>{__free_pages+47}
       <ffffffff80233bb0>{free_pages+128}
       <ffffffff802580df>{free_task+26}
       <ffffffff80245b52>{__put_task_struct+182}
       <ffffffff8025d86e>{thread_return+163}
       <ffffffff8025e876>{rt_lock_slowlock+169}
       <ffffffff8025e0e3>{preempt_schedule_irq+78}
       <ffffffff80259fa6>{retint_kernel+38}
       <ffffffff80209d21>{get_page_from_freelist+204}
       <ffffffff80209ce0>{get_page_from_freelist+139}
       <ffffffff8020dee1>{__alloc_pages+116}
       <ffffffff8022180a>{anon_vma_prepare+44}
       <ffffffff80208468>{__handle_mm_fault+454}
       <ffffffff8028f188>{rt_mutex_slowtrylock+174}
       <ffffffff8020a705>{do_page_fault+1058}
       <ffffffff8025eaa6>{rt_lock_slowunlock+98}
       <ffffffff8025f4a9>{__lock_text_start+9}
       <ffffffff8025a2f1>{error_exit+0}
---------------------------
| preempt count: 00000003 ]
| 3-level deep critical section nesting:
----------------------------------------
.. [<ffffffff8025d303>] .... __schedule+0xb3/0x57b
.....[<ffffffff8025e0e3>] ..   ( <= preempt_schedule_irq+0x4e/0x84)
.. [<ffffffff8025e805>] .... rt_lock_slowlock+0x38/0x277
.....[<ffffffff8025f4b8>] ..   ( <= rt_lock+0xd/0xf)
.. [<ffffffff80263268>] .... oops_begin+0x1b/0x55
.....[<ffffffff802638ff>] ..   ( <= die+0x19/0x44)


Code: 0f 0b 68 71 7e 3f 80 c2 7f 02 65 48 8b 04 25 00 00 00 00 41
RIP <ffffffff8025e89e>{rt_lock_slowlock+209} RSP <ffff8107ed70f9f8>
 <6>note: ld[7332] exited with preempt_count 2

A later example did the same thing, then started "wigging out",
eventually declaring:

 <1>Fixing recursive fault but reboot is needed!

I have a full trace and sysrq-T for this as well.

-- 
Robert Crocombe
rcrocomb@gmail.com