2.6.24 regression: reference count leak in PPPoE

2.6.24 regression: reference count leak in PPPoE

[Andi Kleen]

My workstation running 2.6.24-rc8 just hung during shutdown with an endless 
(or rather I didn't wait more than a few minutes) loop of 

unregister_netdev: waiting for ppp-device to become free. Usage count = 1

ppp-device was an active PPPoE device.

No more information currently.

-Andi

Re: 2.6.24 regression: reference count leak in PPPoE

[Ingo Molnar]

* Andi Kleen <ak@suse.de> wrote:

> My workstation running 2.6.24-rc8 just hung during shutdown with an 
> endless (or rather I didn't wait more than a few minutes) loop of
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count 
> = 1
> 
> ppp-device was an active PPPoE device.
> 
> No more information currently.

i've seen such problems (locked up box with endless loop of usage count 
== 1) with pppoe in the past, and it seemed to be related to dynamic 
IPs. (i saw that well before 2.6.24 - reported it once to davem)

It seems to have stopped when i stopped using ipsec and started using 
vpnc. (but no firm info - this was sporadic - happened every few months 
or so) Are you using ipsec and dynamic IPs by any chance?

	Ingo

Re: 2.6.24 regression: reference count leak in PPPoE

[Andi Kleen]

> It seems to have stopped when i stopped using ipsec and started using
> vpnc.

Kernel ipsec was active yes. However I normally don't see it although
it is often active, that was the first time I think

(except long ago) 

> (but no firm info - this was sporadic - happened every few months 
> or so) Are you using ipsec and dynamic IPs by any chance?

and the ISP uses dynamic IPs.

-Andi

Re: 2.6.24 regression: reference count leak in PPPoE

[David Miller]

From: Ingo Molnar <mingo@elte.hu>
Date: Sun, 20 Jan 2008 21:01:09 +0100

> 
> * Andi Kleen <ak@suse.de> wrote:
> 
> > My workstation running 2.6.24-rc8 just hung during shutdown with an 
> > endless (or rather I didn't wait more than a few minutes) loop of
> > 
> > unregister_netdev: waiting for ppp-device to become free. Usage count 
> > = 1
> > 
> > ppp-device was an active PPPoE device.
> > 
> > No more information currently.
> 
> i've seen such problems (locked up box with endless loop of usage count 
> == 1) with pppoe in the past, and it seemed to be related to dynamic 
> IPs. (i saw that well before 2.6.24 - reported it once to davem)

No, this is a different bug Andi is seeing and it was
recently introduced:

	http://bugzilla.kernel.org/show_bug.cgi?id=9778

Re: 2.6.24 regression: reference count leak in PPPoE

[nigel]

Hi.

Quoting Ingo Molnar <mingo@elte.hu>:

>
> * Andi Kleen <ak@suse.de> wrote:
>
>> My workstation running 2.6.24-rc8 just hung during shutdown with an
>> endless (or rather I didn't wait more than a few minutes) loop of
>>
>> unregister_netdev: waiting for ppp-device to become free. Usage count
>> = 1
>>
>> ppp-device was an active PPPoE device.
>>
>> No more information currently.
>
> i've seen such problems (locked up box with endless loop of usage count
> == 1) with pppoe in the past, and it seemed to be related to dynamic
> IPs. (i saw that well before 2.6.24 - reported it once to davem)
>
> It seems to have stopped when i stopped using ipsec and started using
> vpnc. (but no firm info - this was sporadic - happened every few months
> or so) Are you using ipsec and dynamic IPs by any chance?

This isn't PPPoE specific. It has also been seen with e1000, madwifi  
and an intel based card. It was introduced by a Jan 10 commit post rc7  
(sorry, don't have the details right now - my laptop died yesterday).  
A bugzilla has already been opened.

Nigel

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Re: 2.6.24 regression: reference count leak in PPPoE

[Daniel Lezcano]

Andi Kleen wrote:
> My workstation running 2.6.24-rc8 just hung during shutdown with an endless 
> (or rather I didn't wait more than a few minutes) loop of 
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count = 1
> 
> ppp-device was an active PPPoE device.
> 
> No more information currently.
> 
> -Andi
> --
> To unsubscribe from this list: send the line "unsubscribe netdev" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 

I think this bug has been identified.

[Bug 9778] New: unregister_netdevice: waiting for [device] to become free

Thanks.
   -- Daniel

Re: 2.6.24 regression: reference count leak in PPPoE

[Frans Pop]

Andi Kleen wrote:
> My workstation running 2.6.24-rc8 just hung during shutdown with an
> endless (or rather I didn't wait more than a few minutes) loop of
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count = 1

Same as http://lkml.org/lkml/2008/1/20/27? See also follow-up to that.

Cheers,
FJP

Re: 2.6.24 regression: reference count leak in PPPoE

[Malte Schröder]

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On Sun, 20 Jan 2008 20:53:30 +0100
Andi Kleen <ak@suse.de> wrote:

> 
> My workstation running 2.6.24-rc8 just hung during shutdown with an endless 
> (or rather I didn't wait more than a few minutes) loop of 
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count = 1
> 
> ppp-device was an active PPPoE device.
> 
> No more information currently.

Now that you mention it, this happened to me too this morning. My
system stops the ppp interface (pppoe) and starts it again (my provider
shuts down the link every 24 hours, I want that to happen during the
night, so I do a ifdown ppp0).




-- 
---------------------------------------
Malte Schröder
MalteSch@gmx.de
ICQ# 68121508
---------------------------------------


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Re: 2.6.24 regression: reference count leak in PPPoE

[Pavel Machek]

Hi!

> My workstation running 2.6.24-rc8 just hung during shutdown with an endless 
> (or rather I didn't wait more than a few minutes) loop of 
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count = 1
> 
> ppp-device was an active PPPoE device.
> 
> No more information currently.

Actually, I'm getting something similar:

usb 2-2: USB disconnect, address 23
PM: Removing info for No Bus:usbdev2.23_ep83
usb0: unregister 'cdc_ether' usb-0000:00:1d.0-2, CDC Ethernet Device
PM: Removing info for No Bus:usb0
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
unregister_netdevice: waiting for usb0 to become free. Usage count = 1
PM: Removing info for usb:2-2:1.0
PM: Removing info for No Bus:usbdev2.23_ep81
PM: Removing info for No Bus:usbdev2.23_ep02

The unregister_netdevice made it onto console, that means pretty
severe log level. Happened while playing with openmoko connected with
USB cable.
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: 2.6.24 regression: reference count leak in PPPoE

[David Miller]

From: Andi Kleen <ak@suse.de>
Date: Sun, 20 Jan 2008 20:53:30 +0100

> 
> My workstation running 2.6.24-rc8 just hung during shutdown with an endless 
> (or rather I didn't wait more than a few minutes) loop of 
> 
> unregister_netdev: waiting for ppp-device to become free. Usage count = 1
> 
> ppp-device was an active PPPoE device.
> 
> No more information currently.

http://bugzilla.kernel.org/show_bug.cgi?id=9778