2.6.24-rc8 ppp regression

2.6.24-rc8 ppp regression

[maximilian attems]

when killing a wvdial usb modem session:

Jan 22 23:23:03 dual pppd[7941]: Terminating on signal 15
Jan 22 23:23:03 dual pppd[7941]: Connect time 92.2 minutes.
Jan 22 23:23:03 dual pppd[7941]: Sent 1322316 bytes, received 8587156 bytes.
Jan 22 23:23:03 dual pppd[7941]: Connection terminated.
Jan 22 23:23:05 dual kernel: usb 3-2: USB disconnect, address 5
Jan 22 23:23:05 dual kernel: option 3-2:1.0: device disconnected
Jan 22 23:23:05 dual kernel: option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
Jan 22 23:23:05 dual kernel: option 3-2:1.1: device disconnected
Jan 22 23:23:13 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1
Jan 22 23:23:44 dual last message repeated 3 times
Jan 22 23:23:54 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1


2.6.24-rc7 works fine, not yet bisected, will do later in the evening.

-- 
maks

Re: 2.6.24-rc8 ppp regression

[Ben Hutchings]

maximilian attems wrote:
> 
> when killing a wvdial usb modem session:
> 
> Jan 22 23:23:03 dual pppd[7941]: Terminating on signal 15
> Jan 22 23:23:03 dual pppd[7941]: Connect time 92.2 minutes.
> Jan 22 23:23:03 dual pppd[7941]: Sent 1322316 bytes, received 8587156 bytes.
> Jan 22 23:23:03 dual pppd[7941]: Connection terminated.
> Jan 22 23:23:05 dual kernel: usb 3-2: USB disconnect, address 5
> Jan 22 23:23:05 dual kernel: option 3-2:1.0: device disconnected
> Jan 22 23:23:05 dual kernel: option1 ttyUSB1: GSM modem (1-port) converter now disconnected from ttyUSB1
> Jan 22 23:23:05 dual kernel: option 3-2:1.1: device disconnected
> Jan 22 23:23:13 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1
> Jan 22 23:23:44 dual last message repeated 3 times
> Jan 22 23:23:54 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1

This is a known bug which doesn't just affect PPP:
<http://bugzilla.kernel.org/show_bug.cgi?id=9778>.

Ben.

-- 
Ben Hutchings, Senior Software Engineer, Solarflare Communications
Not speaking for my employer; that's the marketing department's job.

Re: 2.6.24-rc8 ppp regression

[David Miller]

From: maximilian attems <max@stro.at>
Date: Wed, 23 Jan 2008 10:35:09 +0100

> Jan 22 23:23:54 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1

Already fixed by:

[NEIGH]: Revert 'Fix race between neigh_parms_release and neightbl_fill_parms'

Commit 9cd40029423701c376391da59d2c6469672b4bed (Fix race between
neigh_parms_release and neightbl_fill_parms) introduced device
reference counting regressions for several people, see:

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

for example.

Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index cc8a2f1..29b8ee4 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1316,6 +1316,8 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
 			*p = parms->next;
 			parms->dead = 1;
 			write_unlock_bh(&tbl->lock);
+			if (parms->dev)
+				dev_put(parms->dev);
 			call_rcu(&parms->rcu_head, neigh_rcu_free_parms);
 			return;
 		}
@@ -1326,8 +1328,6 @@ void neigh_parms_release(struct neigh_table *tbl, struct neigh_parms *parms)
 
 void neigh_parms_destroy(struct neigh_parms *parms)
 {
-	if (parms->dev)
-		dev_put(parms->dev);
 	kfree(parms);
 }
 

Re: 2.6.24-rc8 ppp regression

[maximilian attems]

On Wed, Jan 23, 2008 at 02:58:54AM -0800, David Miller wrote:
> From: maximilian attems <max@stro.at>
> Date: Wed, 23 Jan 2008 10:35:09 +0100
> 
> > Jan 22 23:23:54 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1
> 
> Already fixed by:
> 

thanks.

-- 
maks

Re: 2.6.24-rc8 ppp regression

[Evgeniy Polyakov]

On Wed, Jan 23, 2008 at 10:35:09AM +0100, maximilian attems (max@stro.at) wrote:
> Jan 22 23:23:13 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1
> Jan 22 23:23:44 dual last message repeated 3 times
> Jan 22 23:23:54 dual kernel: unregister_netdevice: waiting for ppp0 to become free. Usage count = 1
> 
> 2.6.24-rc7 works fine, not yet bisected, will do later in the evening.

Fix (revert) is in Dave's tree already.

-- 
	Evgeniy Polyakov