Re: [patch] Real-Time Preemption, -RT-2.6.12-rc1-V0.7.43-00

Steven Rostedt
2005-04-02T22:12:58Z

On Sat, 2005-04-02 at 15:44 -0500, Steven Rostedt wrote:
> On Sat, 2005-04-02 at 22:35 +0200, Ingo Molnar wrote:

> > >
> > > FYI
> > >
> > > For kicks I ran this on 2.6.11-rc2-RT-V0.7.36-02 (I still had it as a
> > > Grub option), and the system just locked up hard. I just was curious
> > > if this was from a different change. But at least in the latest it
> > > shows output, and not just a hard lockup.
> > >
> > > Oh, the bug report was running kernel 2.6.12-rc1-RT-V0.7.43-06.
> >
> > ok, so it's not the recent NFS changes.
> >
>
> I may need to take this back. I forgot to open the serial, so it wasn't
> accepting input. So it would just appear dead. And the console was
> fighting against the RT tasks, so it too would seem to be dead. I've
> reran the test on the latest, but this time I didn't have the NFS
> mounted, and it's still running.
>

I tried the 2.6.12-rc1-RT-V0.7.43-06 kernel again, and I still have the
serial, to do sysrq. The console is using X which locks (even all the
ctrl-alt-X functions) and the ssh session that I run the test stops
after the processes try to grab the locks. It doesn't reply to ping. But
the sysrq from the serial shows constantly:

s test3_rt: 2269 [cf304690, 89] (not blocked)
s test3_rt: 2270 [cf304050, 88] (not blocked)
s test3_rt: 2271 [cef86cb0, 87] (not blocked)
s test3_rt: 2272 [cef86670, 86] (not blocked)
R test3_rt: 2273 [cf28a050, 85] (not blocked)

So it seems that it's in a deadlock somewhere. Since the 43-06 gets much
further, this seems to be another problem. I'm not going to look at this
problem anymore, since it doesn't show up in the lastest.

I'll run a few more tests to see if I can narrow things down on 43-06.

-- Steve