Messages in this thread | | | Date | Mon, 26 May 2008 18:23:28 +0200 | From | Ingo Molnar <> | Subject | Re: [bug] stuck localhost TCP connections, v2.6.26-rc3+ |
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* Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> wrote:
> On Mon, 26 May 2008, Ingo Molnar wrote: > > > there's a hung distcc task on the system, waiting for socket action > > forever: > > > > [root@europe ~]# strace -fp 19578 > > Process 19578 attached - interrupt to quit > > select(5, NULL, [4], [4], {82, 90000} <unfinished ...> > > 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.
> > disturbing that task via strace did not change the state of the > > socket - and that's not unexpected as it's a select(). [TCP state > > might be affected if strace impacted a recvmsg or a sendmsg wait > > directly.] > > I fail to understand this paragraph due to excessive negation... :-)
i mean, sometimes a TCP connection can get 'unstuck' if you strace a task - that is because the TCP related syscall the task sits in gets interrupted. But in this case it's select() which doesnt explicitly take the socket, doesnt do any tcp_push_pending_frames() processing, etc. - it just its on the socket waitqueue AFAICS. And that's expected.
Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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