From: Vladimir B. Savkin <hidden> Date: 2004-08-13 08:05:09
On Thu, Aug 12, 2004 at 08:18:28PM +0100, Nuno Silva wrote:
Hi!
With 2.6.8-rc4-bk1 I get "Aug 12 17:33:10 puma kernel:
unregister_netdevice: waiting for ppp0 to become free. Usage count = 1"
in the logs after pppd exit.
Also, the box won't reboot and print that message forever in the
console. sysrq-U && sysrq-R did it :-)
The last version I tried was 2.6.8-rc2-bk11 and, wrt this prob, is
running fine. So, the problem is in that window and the changelog for
rc4 mentions something about ppp:
http://kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.8-rc4
If someone requires more information or tests feel free to ask!
I saw this too, with 2.6.7-rc3-mm1.
I have discovered that it happens because of idle TCP socket
holds a reference to a network device.
After killing associated process, device was freed immediately.
~
:wq
With best regards,
Vladimir Savkin.
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Vladimir B. Savkin wrote:
| On Thu, Aug 12, 2004 at 08:18:28PM +0100, Nuno Silva wrote:
|
|>Hi!
|>
|>With 2.6.8-rc4-bk1 I get "Aug 12 17:33:10 puma kernel:
|>unregister_netdevice: waiting for ppp0 to become free. Usage count = 1"
|>in the logs after pppd exit.
|>
|>Also, the box won't reboot and print that message forever in the
|>console. sysrq-U && sysrq-R did it :-)
|>
|>The last version I tried was 2.6.8-rc2-bk11 and, wrt this prob, is
|>running fine. So, the problem is in that window and the changelog for
|>rc4 mentions something about ppp:
|>http://kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.8-rc4
|>
|>If someone requires more information or tests feel free to ask!
|
|
| I saw this too, with 2.6.7-rc3-mm1.
| I have discovered that it happens because of idle TCP socket
| holds a reference to a network device.
| After killing associated process, device was freed immediately.
|
I waited for 5 mins before sysrq-U && sysrq-R.
Anyway, if I 'killall pppd' and then issue 'ifconfig -a' the ifconfig
command will hang.
This didn't happen with 2.6.8-rc2-bk11 (the one I'm running now), so
something changed... I'm I the only one with ppp/pppd/pppoe who tried
2.6.8-rc4-bk1? :-) Any success reports?
Regards,
Nuno Silva
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Vladimir B. Savkin wrote:
| On Thu, Aug 12, 2004 at 08:18:28PM +0100, Nuno Silva wrote:
|
|>Hi!
|>
|>With 2.6.8-rc4-bk1 I get "Aug 12 17:33:10 puma kernel:
|>unregister_netdevice: waiting for ppp0 to become free. Usage count = 1"
|>in the logs after pppd exit.
|>
|>Also, the box won't reboot and print that message forever in the
|>console. sysrq-U && sysrq-R did it :-)
|>
|>The last version I tried was 2.6.8-rc2-bk11 and, wrt this prob, is
|>running fine. So, the problem is in that window and the changelog for
|>rc4 mentions something about ppp:
|>http://kernel.org/pub/linux/kernel/v2.6/testing/ChangeLog-2.6.8-rc4
|>
|>If someone requires more information or tests feel free to ask!
|
|
| I saw this too, with 2.6.7-rc3-mm1.
| I have discovered that it happens because of idle TCP socket
| holds a reference to a network device.
| After killing associated process, device was freed immediately.
|
I waited for 5 mins before sysrq-U && sysrq-R.
Anyway, if I 'killall pppd' and then issue 'ifconfig -a' the ifconfig
command will hang.
This didn't happen with 2.6.8-rc2-bk11 (the one I'm running now), so
something changed... I'm I the only one with ppp/pppd/pppoe who tried
2.6.8-rc4-bk1? :-) Any success reports?
OK, I just tested again and the problem persists. However this time I
had some spare moments so I rebooted a few times to isolate the problem.
The problem is in the QoS code. If I start ppp whithout the
/etc/ppp/ip-up.d/wshaper script everything is fine. If I try the
wshaper.htb it's also fine. So, I'd say that the problem is in the CBQ
section. This time I waited for 1 hour and got hundreds of
"unregister_netdevice: waiting for ppp0 to become free. Usage count = 1"
in the console/syslog. pppd eats 99% CPU. ifconfig freezes. Even reboot
isn't possible without sysrq's help.
This problem was introduced between 2.6.8-rc2-bk11 and 2.6.8-rc4-bk1 and
always happens. Right now I'm testing with 2.6.8.1 with a patch from Mr.
Miller -- "cacheline-align qdisc data in qdisc_create()" (attached).
If someone needs more details feel free to ask!
Regards,
Nuno Silva
From: David S. Miller <hidden> Date: 2004-08-22 05:25:41
On Sun, 22 Aug 2004 03:13:55 +0100
Nuno Silva [off-list ref] wrote:
This problem was introduced between 2.6.8-rc2-bk11 and 2.6.8-rc4-bk1 and
always happens. Right now I'm testing with 2.6.8.1 with a patch from Mr.
Miller -- "cacheline-align qdisc data in qdisc_create()" (attached).
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David S. Miller wrote:
| On Sun, 22 Aug 2004 03:13:55 +0100
| Nuno Silva [off-list ref] wrote:
|
|
|>This problem was introduced between 2.6.8-rc2-bk11 and 2.6.8-rc4-bk1 and
|>always happens. Right now I'm testing with 2.6.8.1 with a patch from Mr.
|>Miller -- "cacheline-align qdisc data in qdisc_create()" (attached).
|
|
| Does that patch fix the problem?
|
Hi!
No, but that patch is necessary for me to use QoS at all, or the kernel
oopses.
I was refering to that patch for you to know that's not the same
problem. Sorry for not being 100% clear.
If you want to freeze your networking :-) you can do this:
remove pppd (or adjust the ppp0 interface name later)
# killall pppd
# sleep 10
make a fony connection to 1.1.1.2 using /dev/null
#pppd /dev/null connect /bin/true persist demand 1.1.1.1:1.1.1.2
# sleep 1
add a CBQ root to ppp0 (or ppp1, if you didn't killall and have another
running)
# tc qdisc add dev ppp0 root handle 1: cbq avpkt 1000 bandwidth 10mbit
ping the fony remote:
# ping 1.1.1.2
kill pppd
#killall pppd
Now check dmesg, you should get "unregister_netdevice: waiting for ppp0
to become free. Usage count = 1"
Another remark: In single user mode pppd died and system load is 0. In
initlevel 3, pppd eats all my CPU... Don't know why.
Right now I'm testing 2.6.8.1-ck3 (because of that can't-burn-cdrom
thing and other stuff) so the attached /proc/config.gz is somewhat
non-vanilla, but this happens with 2.6.8-rc4-bk1[*] and above.
[*] this version is "bad" and 2.6.8-rc2-bk11 is "good". Didn't test with
rc3...
As you can see in the .config I'm using the OLD POLICER.
As always, please request more info if you need it! :-)
Regards,
Nuno Silva
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From: Herbert Xu <herbert@gondor.apana.org.au> Date: 2004-08-22 08:15:07
Nuno Silva [off-list ref] wrote:
The problem is in the QoS code. If I start ppp whithout the
OK, this appears to be due to the changeset titled
[PKT_SCHED]: Refcount qdisc->dev for __qdisc_destroy rcu-callback
It adds a reference to dev.
I don't see any code that cleans up that reference when the dev goes
down. So someone needs to add that similar to the code in net/core/dst.c.
Patrick, could you please have a look at this?
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} [off-list ref]
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
From: Patrick McHardy <hidden> Date: 2004-08-22 12:41:03
Herbert Xu wrote:
Nuno Silva [off-list ref] wrote:
quoted
The problem is in the QoS code. If I start ppp whithout the
OK, this appears to be due to the changeset titled
[PKT_SCHED]: Refcount qdisc->dev for __qdisc_destroy rcu-callback
It adds a reference to dev.
I don't see any code that cleans up that reference when the dev goes
down. So someone needs to add that similar to the code in net/core/dst.c.
Patrick, could you please have a look at this?
The reference is dropped in __qdisc_destroy. The problem lies in the CBQ
qdisc, it doesn't destroy the root-class and leaks the inner qdisc. These
two patches for 2.4 and 2.6 fix the problem.
Regards
Patrick
From: David S. Miller <hidden> Date: 2004-08-23 04:49:22
On Sun, 22 Aug 2004 14:39:57 +0200
Patrick McHardy [off-list ref] wrote:
Herbert Xu wrote:
quoted
Nuno Silva [off-list ref] wrote:
quoted
The problem is in the QoS code. If I start ppp whithout the
OK, this appears to be due to the changeset titled
[PKT_SCHED]: Refcount qdisc->dev for __qdisc_destroy rcu-callback
It adds a reference to dev.
I don't see any code that cleans up that reference when the dev goes
down. So someone needs to add that similar to the code in net/core/dst.c.
Patrick, could you please have a look at this?
The reference is dropped in __qdisc_destroy. The problem lies in the CBQ
qdisc, it doesn't destroy the root-class and leaks the inner qdisc. These
two patches for 2.4 and 2.6 fix the problem.
Awesome, good detective work guys.
Patch applied, thanks.
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Patrick McHardy wrote:
| Herbert Xu wrote:
|
|> Nuno Silva [off-list ref] wrote:
|>
|>
|>> The problem is in the QoS code. If I start ppp whithout the
|>
|>
|> OK, this appears to be due to the changeset titled
|>
|> [PKT_SCHED]: Refcount qdisc->dev for __qdisc_destroy rcu-callback
|>
|> It adds a reference to dev.
|>
|> I don't see any code that cleans up that reference when the dev goes
|> down. So someone needs to add that similar to the code in
|> net/core/dst.c.
|>
|> Patrick, could you please have a look at this?
|>
|>
| The reference is dropped in __qdisc_destroy. The problem lies in the CBQ
| qdisc, it doesn't destroy the root-class and leaks the inner qdisc. These
| two patches for 2.4 and 2.6 fix the problem.
Hi!
Just to give some feedback: IT WORKS! Thanks!
Didn't try with 2.4, but it works very well with 2.6.8.1.
Thanks again,
Nuno Silva
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From: David S. Miller <redacted>
Date: Sun, Aug 22, 2004 at 09:47:46PM -0700
On Sun, 22 Aug 2004 14:39:57 +0200
Patrick McHardy [off-list ref] wrote:
quoted
Herbert Xu wrote:
quoted
Nuno Silva [off-list ref] wrote:
OK, this appears to be due to the changeset titled
[PKT_SCHED]: Refcount qdisc->dev for __qdisc_destroy rcu-callback
It adds a reference to dev.
I don't see any code that cleans up that reference when the dev goes
down. So someone needs to add that similar to the code in net/core/dst.c.
Patrick, could you please have a look at this?
The reference is dropped in __qdisc_destroy. The problem lies in the CBQ
qdisc, it doesn't destroy the root-class and leaks the inner qdisc. These
two patches for 2.4 and 2.6 fix the problem.
Awesome, good detective work guys.
Patch applied, thanks.
I get the same error with 2.6.9-rc1-mm1, but now for my ipv6-over-ipv4
tunnel.
unregister_netdevice: waiting for xs6all to become free
etc. when trying to reboot or shutdown. Usage count = 1
I'm pretty sure I didn't see this in 2.6.8.1 nor in 2.6.8.1-mm1.
This is a plain ipv6-over-ipv4 tunnel like this:
/etc/network/interfaces:
auto xs6all
iface xs6all inet6 v4tunnel
endpoint xxx.xxx.xxx.xxx
up ip route add 2000::0/3 via xxx:xxx:xxx:xxx:xxx:xxx
address xxx:xxx:xxx:xxx:xxx:xxx
netmask 64
up ip tunnel change xs6all ttl 64
I'm running Debian Unstable with all the latest updates as of today.
Thanks for any hints,
Jurriaan
--
"At least she's on our side," said Lindholm.
Corbie looked at him. "Investigators aren't on anybody's side."
Simon R Green - Hellworld
Debian (Unstable) GNU/Linux 2.6.9-rc1 2x6078 bogomips load 0.46