kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Konrad Rzeszutek Wilk]

Hey Greg,

With or without your previous patch (the one that added an cpu_device_release
function) I am getting this in 3.3-rc2.  I did not get this in 3.2.

I added some extra printks to make sure that the handle_vcpu_hotplug_event
code actually did call 'arch_unregister_cpu' which is certainly looks
to be doing.

I hadn't done a bisection yet, but was wondering if this is related
to the previous issues with the sysdev. Or kobject getting more observant.


[   34.984105] Disabling CPU3 present 
[   34.984801] arch_unregister_cpu: CPU 3

sh-4.1# 
sh-4.1# 
sh-4.1# [   42.297542] Contemplating CPU 0 which should be online
[   42.298447] Enabling CPU0 present online
[   42.299229] Contemplating CPU 1 which should be online
[   42.300001] Enabling CPU1 present online
[   42.300783] Contemplating CPU 2 which should be online
[   42.301558] Enabling CPU2 present online
[   42.302387] Contemplating CPU 3 which should be online
[   42.303198] Enabling CPU3  
[   42.303895] arch_register_cpu: CPU 3
[   42.304188] kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.
[   42.304188] Pid: 30, comm: xenwatch Tainted: G           O 3.3.0-rc2-00008-g4b64969 #1
[   42.304188] Call Trace:
[   42.304188]  [<ffffffff812ce4d9>] kobject_init+0x89/0xa0
[   42.304188]  [<ffffffff813ca917>] device_initialize+0x27/0x90
[   42.304188]  [<ffffffff813cbbc1>] device_register+0x11/0x20
[   42.304188]  [<ffffffff815f2210>] register_cpu+0x52/0xb6
[   42.304188]  [<ffffffff815d66c0>] arch_register_cpu+0x60/0x70
[   42.304188]  [<ffffffff8136b095>] handle_vcpu_hotplug_event+0x175/0x180
[   42.304188]  [<ffffffff81367140>] xenwatch_thread+0xb0/0x180
[   42.304188]  [<ffffffff810a7ec0>] ? wake_up_bit+0x40/0x40
[   42.304188]  [<ffffffff81367090>] ? split+0xf0/0xf0
[   42.304188]  [<ffffffff810a77e6>] kthread+0x96/0xa0
[   42.304188]  [<ffffffff815fec24>] kernel_thread_helper+0x4/0x10
[   42.304188]  [<ffffffff815f6b40>] ? retint_restore_args+0x5/0x6
[   42.304188]  [<ffffffff815fec20>] ? gs_change+0x13/0x13

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Greg KH]

On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> Hey Greg,
> 
> With or without your previous patch (the one that added an cpu_device_release
> function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> 
> I added some extra printks to make sure that the handle_vcpu_hotplug_event
> code actually did call 'arch_unregister_cpu' which is certainly looks
> to be doing.
> 
> I hadn't done a bisection yet, but was wondering if this is related
> to the previous issues with the sysdev. Or kobject getting more observant.

No, it's related to the previous issue, let me knock up a patch to fix
this as well...

thanks,

greg k-h

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Greg KH]

On Fri, Feb 03, 2012 at 01:39:49PM -0800, Greg KH wrote:
> On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> > Hey Greg,
> > 
> > With or without your previous patch (the one that added an cpu_device_release
> > function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> > 
> > I added some extra printks to make sure that the handle_vcpu_hotplug_event
> > code actually did call 'arch_unregister_cpu' which is certainly looks
> > to be doing.
> > 
> > I hadn't done a bisection yet, but was wondering if this is related
> > to the previous issues with the sysdev. Or kobject getting more observant.
> 
> No, it's related to the previous issue, let me knock up a patch to fix
> this as well...

Does this patch solve the problem for you?

thanks,

greg k-h

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index 23f2c4c..4dabf50 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -240,6 +240,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
 	int error;
 
 	cpu->node_id = cpu_to_node(num);
+	memset(&cpu->dev, 0x00, sizeof(struct device));
 	cpu->dev.id = num;
 	cpu->dev.bus = &cpu_subsys;
 	cpu->dev.release = cpu_device_release;

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Konrad Rzeszutek Wilk]

On Fri, Feb 03, 2012 at 01:42:35PM -0800, Greg KH wrote:
> On Fri, Feb 03, 2012 at 01:39:49PM -0800, Greg KH wrote:
> > On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> > > Hey Greg,
> > > 
> > > With or without your previous patch (the one that added an cpu_device_release
> > > function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> > > 
> > > I added some extra printks to make sure that the handle_vcpu_hotplug_event
> > > code actually did call 'arch_unregister_cpu' which is certainly looks
> > > to be doing.
> > > 
> > > I hadn't done a bisection yet, but was wondering if this is related
> > > to the previous issues with the sysdev. Or kobject getting more observant.
> > 
> > No, it's related to the previous issue, let me knock up a patch to fix
> > this as well...
> 
> Does this patch solve the problem for you?

Yeah, no warnings. But neither is the CPU coming back up :-(

Thought that might be related to something else  - let me double check
with 3.2 whether there are some race-conditions that I might be hitting.

> 
> thanks,
> 
> greg k-h
> 
> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
> index 23f2c4c..4dabf50 100644
> --- a/drivers/base/cpu.c
> +++ b/drivers/base/cpu.c
> @@ -240,6 +240,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
>  	int error;
>  
>  	cpu->node_id = cpu_to_node(num);
> +	memset(&cpu->dev, 0x00, sizeof(struct device));
>  	cpu->dev.id = num;
>  	cpu->dev.bus = &cpu_subsys;
>  	cpu->dev.release = cpu_device_release;

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Greg KH]

On Mon, Feb 06, 2012 at 01:20:40PM -0500, Konrad Rzeszutek Wilk wrote:
> On Fri, Feb 03, 2012 at 01:42:35PM -0800, Greg KH wrote:
> > On Fri, Feb 03, 2012 at 01:39:49PM -0800, Greg KH wrote:
> > > On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> > > > Hey Greg,
> > > > 
> > > > With or without your previous patch (the one that added an cpu_device_release
> > > > function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> > > > 
> > > > I added some extra printks to make sure that the handle_vcpu_hotplug_event
> > > > code actually did call 'arch_unregister_cpu' which is certainly looks
> > > > to be doing.
> > > > 
> > > > I hadn't done a bisection yet, but was wondering if this is related
> > > > to the previous issues with the sysdev. Or kobject getting more observant.
> > > 
> > > No, it's related to the previous issue, let me knock up a patch to fix
> > > this as well...
> > 
> > Does this patch solve the problem for you?
> 
> Yeah, no warnings. But neither is the CPU coming back up :-(

Very wierd.

> Thought that might be related to something else  - let me double check
> with 3.2 whether there are some race-conditions that I might be hitting.

Ok, I'll wait to queue this up until you get back to me.

greg k-h

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Konrad Rzeszutek Wilk]

On Mon, Feb 06, 2012 at 10:29:56AM -0800, Greg KH wrote:
> On Mon, Feb 06, 2012 at 01:20:40PM -0500, Konrad Rzeszutek Wilk wrote:
> > On Fri, Feb 03, 2012 at 01:42:35PM -0800, Greg KH wrote:
> > > On Fri, Feb 03, 2012 at 01:39:49PM -0800, Greg KH wrote:
> > > > On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> > > > > Hey Greg,
> > > > > 
> > > > > With or without your previous patch (the one that added an cpu_device_release
> > > > > function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> > > > > 
> > > > > I added some extra printks to make sure that the handle_vcpu_hotplug_event
> > > > > code actually did call 'arch_unregister_cpu' which is certainly looks
> > > > > to be doing.
> > > > > 
> > > > > I hadn't done a bisection yet, but was wondering if this is related
> > > > > to the previous issues with the sysdev. Or kobject getting more observant.
> > > > 
> > > > No, it's related to the previous issue, let me knock up a patch to fix
> > > > this as well...
> > > 
> > > Does this patch solve the problem for you?
> > 
> > Yeah, no warnings. But neither is the CPU coming back up :-(
> 
> Very wierd.

Found the culprit and have a patch for it. But it does not affect baremetal and
it was in the drivers/xen/cpu_hotplug.c code - so 

> 
> > Thought that might be related to something else  - let me double check
> > with 3.2 whether there are some race-conditions that I might be hitting.
> 
> Ok, I'll wait to queue this up until you get back to me.

.. you can go ahead and queue it up with my Tested-by tag. Thanks!

Re: kobject (ffff88003ffbb4b8): tried to init an initialized object, something is seriously wrong.

[Greg KH]

On Tue, Feb 07, 2012 at 07:35:37PM -0500, Konrad Rzeszutek Wilk wrote:
> On Mon, Feb 06, 2012 at 10:29:56AM -0800, Greg KH wrote:
> > On Mon, Feb 06, 2012 at 01:20:40PM -0500, Konrad Rzeszutek Wilk wrote:
> > > On Fri, Feb 03, 2012 at 01:42:35PM -0800, Greg KH wrote:
> > > > On Fri, Feb 03, 2012 at 01:39:49PM -0800, Greg KH wrote:
> > > > > On Fri, Feb 03, 2012 at 03:59:53PM -0500, Konrad Rzeszutek Wilk wrote:
> > > > > > Hey Greg,
> > > > > > 
> > > > > > With or without your previous patch (the one that added an cpu_device_release
> > > > > > function) I am getting this in 3.3-rc2.  I did not get this in 3.2.
> > > > > > 
> > > > > > I added some extra printks to make sure that the handle_vcpu_hotplug_event
> > > > > > code actually did call 'arch_unregister_cpu' which is certainly looks
> > > > > > to be doing.
> > > > > > 
> > > > > > I hadn't done a bisection yet, but was wondering if this is related
> > > > > > to the previous issues with the sysdev. Or kobject getting more observant.
> > > > > 
> > > > > No, it's related to the previous issue, let me knock up a patch to fix
> > > > > this as well...
> > > > 
> > > > Does this patch solve the problem for you?
> > > 
> > > Yeah, no warnings. But neither is the CPU coming back up :-(
> > 
> > Very wierd.
> 
> Found the culprit and have a patch for it. But it does not affect baremetal and
> it was in the drivers/xen/cpu_hotplug.c code - so 
> 
> > 
> > > Thought that might be related to something else  - let me double check
> > > with 3.2 whether there are some race-conditions that I might be hitting.
> > 
> > Ok, I'll wait to queue this up until you get back to me.
> 
> .. you can go ahead and queue it up with my Tested-by tag. Thanks!

Great, will do.