Messages in this thread | | | Date | Mon, 26 May 2008 20:08:37 +0300 (EEST) | From | "Ilpo Järvinen" <> | Subject | Re: [bug] stuck localhost TCP connections, v2.6.26-rc3+ |
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On Mon, 26 May 2008, Ingo Molnar wrote:
> > * Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> wrote: > > > > > Hmm, readfds is NULL isn't it?!? Are you sure you straced the > > > > right process? > > > > > > yes, i'm stracing the task that is hung unexpectedly. > > > > But that wasn't the receiving process? (I didn't quickly find into > > which direction distcc ports go, so I couldn't confirm this). If you > > still have that situation at hand, could you check which is the > > receiving process (e.g., using netstat -p, the end which has Recv-Q is > > the right one) and where it's stuck? > > it wasnt the receiving process. There's no receiving process - which is > weird: > > Active Internet connections (w/o servers) > Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name > tcp 0 207232 europe:37198 europe:distcc ESTABLISHED 19578/distcc > tcp 0 0 europe:ssh dione:36284 ESTABLISHED - > tcp 0 0 europe:ssh e2:45910 ESTABLISHED - > tcp 72283 0 europe:distcc europe:37198 ESTABLISHED -
Just to be sure (please forgive me if you find this nearly an insult :-)), did you have enough rights to find out the pid (ie., if that process not owned by you then you need superuser privs for that)?
> i just gave it as a general example of why sometimes stracing a task can > 'disturb' the observed system and can kick the TCP state machine out of > a stall. I did not say it's occuring here.
Yeah, I understood that earlier. Similarly, I just wanted to point out the end where the problem lies :-).
> > ...It may still be that the receiving process is stuck due to the > > non-net related changes you have there. > > the socket does not seem to be owned. It should have closed down? > Refcounting issue?
It's well possible that e.g., net namespaces have some bug in handling of orphaned tcp.
> find below the sysrq-t dump.
...I'll have a look into that as well (though with such I'm on a more unfamiliar territory, so it will take a moment).
-- i. | |