ppp in D+ state

ppp in D+ state

[Michele Mencacci]

Hello there,
I don't know since when, ( before I had 2.6.16 and now I'm passed to
2.6.22.3), but now pppd while is running, it stops, or better it's live,
but I can't send or receive....and if I kill it, it hangs-up the modem,
but it remain live in D+state and I can only reboot the linux box  :(
Instead with 2.6.16 it works fine...well sometime it stops but I can
kill and restart, but less often than 2.6.22.
It appears to be random.....any hints?
greetings

                Mike

Re: ppp in D+ state

[Zygo Blaxell]

In article <46EC9B4B.80809@poste.it>,
Michele Mencacci  <shire@inwind.it> wrote:
>Hello there,
>I don't know since when, ( before I had 2.6.16 and now I'm passed to
>2.6.22.3), but now pppd while is running, it stops, or better it's live,
>but I can't send or receive....and if I kill it, it hangs-up the modem,
>but it remain live in D+state and I can only reboot the linux box  :(
>Instead with 2.6.16 it works fine...well sometime it stops but I can
>kill and restart, but less often than 2.6.22.
>It appears to be random.....any hints?

For what it's worth I see this too (2.6.22.1).

pppd goes into D state, and so does 'ifconfig' and several other
programs that try to use ioctl calls to enumerate network interfaces.
Eventually every process on the system is in D state and I have to reboot
to get anything to work.

I have two ADSL PPPoE feeds.  The second feed continues to work after the
first goes down, except that if the second feed goes down too, its pppd
process gets into the same state.  Actually all attempts to bring any
network interface up or down have the same result:  the process trying to
do this ends up in D state.

Sometimes, though not always, there is a kernel log message which complains
that the ppp interface has reference count = 1.

I've also used 2.6.16.19, 2.6.16.42, and 2.6.18.8, which don't have this
problem, but they did have other bugs which crash the whole machine.

At least with this bug, my system is able to reboot itself if it gets
stuck.  Ah, progress.  ;-)

-- 
Zygo Blaxell (Laptop) <zblaxell@feedme.hungrycats.org>
GPG = B203 9402 B0E7 0F20 3B74  B13C DFBC C916 4395 FD03

Re: ppp in D+ state

[Christopher Fowler]

I had this same problem but my solution may not be a good one.  I had a
server that worked flawlessly for 2 years. It only had 512m of memory
and we decided to upgrade.  I added 2 GB to make a total of 2.5GB.  This
system ran 2.6.5 kernel with FC2.  After the upgrade I saw this problem.
We use vtun and run pppd that way so after about 3 days I would see at
least a 100 pppd processes like this.  Kill -9 did not work and load
average was at 100+.  The system become non-responsive.  I could not log
in.  Luckily I invested in intelligent power strips that saved me a trip
to the data center.  To fix this problem I would issue an off then on
command to the strip for that outlet.  I thought it might have been a
memory issue but I downloaded the 2.6.10 kernel upgrade for FC2,
compiled it and my problem went away.  I'm not sure what was causing
this issue but it only started when I went from 512m to 2.5G of ram.

On Thu, 2007-09-20 at 02:07 -0400, Zygo Blaxell wrote:
> In article <46EC9B4B.80809@poste.it>,
> Michele Mencacci  <shire@inwind.it> wrote:
> >Hello there,
> >I don't know since when, ( before I had 2.6.16 and now I'm passed to
> >2.6.22.3), but now pppd while is running, it stops, or better it's live,
> >but I can't send or receive....and if I kill it, it hangs-up the modem,
> >but it remain live in D+state and I can only reboot the linux box  :(
> >Instead with 2.6.16 it works fine...well sometime it stops but I can
> >kill and restart, but less often than 2.6.22.
> >It appears to be random.....any hints?
> 
> For what it's worth I see this too (2.6.22.1).
> 
> pppd goes into D state, and so does 'ifconfig' and several other
> programs that try to use ioctl calls to enumerate network interfaces.
> Eventually every process on the system is in D state and I have to reboot
> to get anything to work.
> 
> I have two ADSL PPPoE feeds.  The second feed continues to work after the
> first goes down, except that if the second feed goes down too, its pppd
> process gets into the same state.  Actually all attempts to bring any
> network interface up or down have the same result:  the process trying to
> do this ends up in D state.
> 
> Sometimes, though not always, there is a kernel log message which complains
> that the ppp interface has reference count = 1.
> 
> I've also used 2.6.16.19, 2.6.16.42, and 2.6.18.8, which don't have this
> problem, but they did have other bugs which crash the whole machine.
> 
> At least with this bug, my system is able to reboot itself if it gets
> stuck.  Ah, progress.  ;-)
>