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* [BUG-REPORT][PREEMPT-RT] 2.6.33.1-rt11 triggers DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled),  in a 32-bit kvm session
@ 2010-03-26 12:02 John Kacur
  2010-03-26 19:01 ` Thomas Gleixner
  0 siblings, 1 reply; 3+ messages in thread
From: John Kacur @ 2010-03-26 12:02 UTC (permalink / raw)
  To: Thomas Gleixner; +Cc: LKML, RT

During boot-up of 2.6.33.1-rt11 in a 32-bit qemu-kvm machine,
The following warning is reliably (every time) triggered.

------------[ cut here ]------------
WARNING: at /home/jkacur/jk-2.6/kernel/fork.c:1065 copy_process+0x299/0x160f()
Hardware name:
Modules linked in:
Pid: 64, comm: khelper Not tainted 2.6.33.1-rt11 #1
Call Trace:
 [<c104961a>] warn_slowpath_common+0x83/0x9a
 [<c1049643>] warn_slowpath_null+0x12/0x15
 [<c1046f89>] copy_process+0x299/0x160f
 [<c1048711>] do_fork+0x235/0x4e2
 [<c107da08>] ? register_lock_class+0x17/0x22d
 [<c107e6dc>] ? mark_lock+0x1e/0x1c0
 [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
 [<c100ae09>] kernel_thread+0x79/0x81
 [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
 [<c100391c>] ? kernel_thread_helper+0x0/0x10
 [<c1064cc7>] __call_usermodehelper+0x75/0xa0
 [<c10673b6>] worker_thread+0x1f6/0x2fb
 [<c1067374>] ? worker_thread+0x1b4/0x2fb
 [<c1064c52>] ? __call_usermodehelper+0x0/0xa0
 [<c106a91e>] ? autoremove_wake_function+0x0/0x46
 [<c106a740>] kthread+0x6b/0x74
 [<c10671c0>] ? worker_thread+0x0/0x2fb
 [<c106a6d5>] ? kthread+0x0/0x74
 [<c106a6d5>] ? kthread+0x0/0x74
 [<c1003922>] kernel_thread_helper+0x6/0x10
---[ end trace a22d306b065d4a66 ]---

I am happy to provide more information to help debug this.

Thanks

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [BUG-REPORT][PREEMPT-RT] 2.6.33.1-rt11 triggers DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled), in a 32-bit kvm session
  2010-03-26 12:02 [BUG-REPORT][PREEMPT-RT] 2.6.33.1-rt11 triggers DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled), in a 32-bit kvm session John Kacur
@ 2010-03-26 19:01 ` Thomas Gleixner
  2010-03-27 22:56   ` John Kacur
  0 siblings, 1 reply; 3+ messages in thread
From: Thomas Gleixner @ 2010-03-26 19:01 UTC (permalink / raw)
  To: John Kacur; +Cc: LKML, RT

On Fri, 26 Mar 2010, John Kacur wrote:

> During boot-up of 2.6.33.1-rt11 in a 32-bit qemu-kvm machine,
> The following warning is reliably (every time) triggered.
> 
> ------------[ cut here ]------------
> WARNING: at /home/jkacur/jk-2.6/kernel/fork.c:1065 copy_process+0x299/0x160f()
> Hardware name:
> Modules linked in:
> Pid: 64, comm: khelper Not tainted 2.6.33.1-rt11 #1
> Call Trace:
>  [<c104961a>] warn_slowpath_common+0x83/0x9a
>  [<c1049643>] warn_slowpath_null+0x12/0x15
>  [<c1046f89>] copy_process+0x299/0x160f
>  [<c1048711>] do_fork+0x235/0x4e2
>  [<c107da08>] ? register_lock_class+0x17/0x22d
>  [<c107e6dc>] ? mark_lock+0x1e/0x1c0
>  [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
>  [<c100ae09>] kernel_thread+0x79/0x81
>  [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
>  [<c100391c>] ? kernel_thread_helper+0x0/0x10
>  [<c1064cc7>] __call_usermodehelper+0x75/0xa0
>  [<c10673b6>] worker_thread+0x1f6/0x2fb
>  [<c1067374>] ? worker_thread+0x1b4/0x2fb
>  [<c1064c52>] ? __call_usermodehelper+0x0/0xa0
>  [<c106a91e>] ? autoremove_wake_function+0x0/0x46
>  [<c106a740>] kthread+0x6b/0x74
>  [<c10671c0>] ? worker_thread+0x0/0x2fb
>  [<c106a6d5>] ? kthread+0x0/0x74
>  [<c106a6d5>] ? kthread+0x0/0x74
>  [<c1003922>] kernel_thread_helper+0x6/0x10
> ---[ end trace a22d306b065d4a66 ]---
> 
> I am happy to provide more information to help debug this.

Can you run the following patch please ?

Thanks,

	tglx
---

diff --git a/kernel/fork.c b/kernel/fork.c
index 340cbc8..b63e8f5 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1062,7 +1062,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 	rt_mutex_init_task(p);
 
 #ifdef CONFIG_PROVE_LOCKING
-	DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
+	//DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
+	if (!p->hardirqs_enabled)
+		print_irqtrace_events(p);
 	DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
 #endif
 	retval = -EAGAIN;

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [BUG-REPORT][PREEMPT-RT] 2.6.33.1-rt11 triggers  DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled), in a 32-bit kvm session
  2010-03-26 19:01 ` Thomas Gleixner
@ 2010-03-27 22:56   ` John Kacur
  0 siblings, 0 replies; 3+ messages in thread
From: John Kacur @ 2010-03-27 22:56 UTC (permalink / raw)
  To: Thomas Gleixner; +Cc: LKML, RT

On Fri, Mar 26, 2010 at 8:01 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Fri, 26 Mar 2010, John Kacur wrote:
>
>> During boot-up of 2.6.33.1-rt11 in a 32-bit qemu-kvm machine,
>> The following warning is reliably (every time) triggered.
>>
>> ------------[ cut here ]------------
>> WARNING: at /home/jkacur/jk-2.6/kernel/fork.c:1065 copy_process+0x299/0x160f()
>> Hardware name:
>> Modules linked in:
>> Pid: 64, comm: khelper Not tainted 2.6.33.1-rt11 #1
>> Call Trace:
>>  [<c104961a>] warn_slowpath_common+0x83/0x9a
>>  [<c1049643>] warn_slowpath_null+0x12/0x15
>>  [<c1046f89>] copy_process+0x299/0x160f
>>  [<c1048711>] do_fork+0x235/0x4e2
>>  [<c107da08>] ? register_lock_class+0x17/0x22d
>>  [<c107e6dc>] ? mark_lock+0x1e/0x1c0
>>  [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
>>  [<c100ae09>] kernel_thread+0x79/0x81
>>  [<c1064a2f>] ? ____call_usermodehelper+0x0/0x138
>>  [<c100391c>] ? kernel_thread_helper+0x0/0x10
>>  [<c1064cc7>] __call_usermodehelper+0x75/0xa0
>>  [<c10673b6>] worker_thread+0x1f6/0x2fb
>>  [<c1067374>] ? worker_thread+0x1b4/0x2fb
>>  [<c1064c52>] ? __call_usermodehelper+0x0/0xa0
>>  [<c106a91e>] ? autoremove_wake_function+0x0/0x46
>>  [<c106a740>] kthread+0x6b/0x74
>>  [<c10671c0>] ? worker_thread+0x0/0x2fb
>>  [<c106a6d5>] ? kthread+0x0/0x74
>>  [<c106a6d5>] ? kthread+0x0/0x74
>>  [<c1003922>] kernel_thread_helper+0x6/0x10
>> ---[ end trace a22d306b065d4a66 ]---
>>
>> I am happy to provide more information to help debug this.
>
> Can you run the following patch please ?
>
> Thanks,
>
>        tglx
> ---
>
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 340cbc8..b63e8f5 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1062,7 +1062,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
>        rt_mutex_init_task(p);
>
>  #ifdef CONFIG_PROVE_LOCKING
> -       DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
> +       //DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
> +       if (!p->hardirqs_enabled)
> +               print_irqtrace_events(p);
>        DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
>  #endif
>        retval = -EAGAIN;
> --

With the above patch I got the following.

8139cp: 10/100 PCI Ethernet driver v1.3 (Mar 22, 2004)
ACPI: PCI Interrupt Link [LNKC] enabled at IRQ 10
8139cp 0000:00:03.0: PCI INT A -> Link[LNKC] -> GSI 10 (level, high) -> IRQ 10
eth0: RTL-8139C+ at 0xf886c000, 52:54:00:3c:11:54, IRQ 10
8139cp 0000:00:03.0: setting latency timer to 64
irq event stamp: 5988
hardirqs last  enabled at (5987): [<c13e4696>]
_raw_spin_unlock_irqrestore+0x49/0x8f
hardirqs last disabled at (5988): [<c13e4ce3>] call_function_interrupt+0x2f/0x3c
softirqs last  enabled at (0): [<c10470a6>] copy_process+0x3b6/0x15ad
softirqs last disabled at (0): [<(null)>] (null)
8139too Fast Ethernet driver 0.9.28
irq event stamp: 10638
hardirqs last  enabled at (10637): [<c13e4696>]
_raw_spin_unlock_irqrestore+0x49/0x8f
hardirqs last disabled at (10638): [<c13e4feb>] apic_timer_interrupt+0x2f/0x3c
softirqs last  enabled at (0): [<c10470a6>] copy_process+0x3b6/0x15ad
softirqs last disabled at (0): [<(null)>] (null)
irq event stamp: 2914
hardirqs last  enabled at (2913): [<c13e4696>]
_raw_spin_unlock_irqrestore+0x49/0x8f
hardirqs last disabled at (2914): [<c13e4feb>] apic_timer_interrupt+0x2f/0x3c
softirqs last  enabled at (0): [<c10470a6>] copy_process+0x3b6/0x15ad
softirqs last disabled at (0): [<(null)>] (null)


and then

irq event stamp: 36510
hardirqs last  enabled at (36509): [<c13e4696>]
_raw_spin_unlock_irqrestore+0x49/0x8f
hardirqs last disabled at (36510): [<c13e4feb>] apic_timer_interrupt+0x2f/0x3c
softirqs last  enabled at (0): [<c10470a6>] copy_process+0x3b6/0x15ad
softirqs last disabled at (0): [<(null)>] (null)
eth0: no IPv6 routers present
irq event stamp: 103682
hardirqs last  enabled at (103681): [<c13e4696>]
_raw_spin_unlock_irqrestore+0x49/0x8f
hardirqs last disabled at (103682): [<c13e4feb>] apic_timer_interrupt+0x2f/0x3c
softirqs last  enabled at (0): [<c10470a6>] copy_process+0x3b6/0x15ad
softirqs last disabled at (0): [<(null)>] (null)

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2010-03-27 22:56 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2010-03-26 12:02 [BUG-REPORT][PREEMPT-RT] 2.6.33.1-rt11 triggers DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled), in a 32-bit kvm session John Kacur
2010-03-26 19:01 ` Thomas Gleixner
2010-03-27 22:56   ` John Kacur

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