Re: ftpd problems (probably kernel's fault)

[Andrew Doran <ad%netbsd.org@localhost>]

On Tue, Apr 29, 2008 at 02:46:03PM +0200, Julio M. Merino Vidal wrote:

> On Tue, Apr 29, 2008 at 9:14 AM, Julio M. Merino Vidal 
> <jmmv84%gmail.com@localhost> wrote:
> > On Mon, Apr 28, 2008 at 6:41 PM, Andrew Doran <ad%netbsd.org@localhost> 
> > wrote:
> >
> >  >  Ok, can you try with sys/socketvar.h 1.107? It should fix it.
> >
> >  With today's sources, I cannot even access the network.  I can ftp
> >  localhost but still have the same problems as before.  However, I
> >  can't access any remote machine; all the connections get stalled,
> >  sometimes during DNS resolution, sometimes after.
> 
> Bleh.  The network does work; it turned out that connectivity at the
> university broke at the exact same moment I was doing these tests (and
> returned when I switched to the old kernel).
> 
> With your change, the message:
> 
>     ftp: Can't send abort message: No buffer space available
> 
> is gone, but connections to the local ftpd still get stalled.

Can you see what ftpd is stalled on? Could you please get a backtrace from
it, and any other threads hanging in tstile or anything else that is
interesting?

You can get a kernel backtrace using ddb, or gdb. For gdb run the following

        ps -axs -o pid,lid,wchan,laddr,comm | grep -i whatever

Pick an interesting value of laddr.. Then

gdb /mykernel
target kvm /dev/mem
kvm proc $laddr
bt

Thanks,
Andrew