Re: frequent softlockups with 3.10rc6.

From: Steven Rostedt
Date: Wed Jun 26 2013 - 15:52:21 EST


On Wed, 2013-06-26 at 01:23 -0400, Dave Jones wrote:
> On Tue, Jun 25, 2013 at 12:23:34PM -0400, Steven Rostedt wrote:
>
> > Now, what we can try to do as well, is to add a trigger to disable
> > tracing, which should (I need to check the code) stop tracing on printk.
> > To do so:
> >
> > # echo printk:traceoff > /sys/kernel/debug/tracing/set_ftrace_filter
> >
> > This will add a trigger to the printk function that when called, will
> > disable tracing. If it is hit before you get your trace, you can just
> > re-enable tracing with:
> >
> > # echo 1 > /sys/kernel/debug/tracing/tracing_on
> >
> > Hmm, no it needs a fix to make this work. I applied a patch below that
> > should do this correctly (and will put this into my 3.11 queue).
> >
> > If you run the test again with this change and with the above filter, it
> > should stop the trace before overwriting the first dump, as it should
> > ignore the printk output.
>
> I think something isn't right with this patch.
> After 10 hours, I hit the bug again, but...
>
> (01:21:28:root@binary:tracing)# cat trace
> # tracer: preemptirqsoff
> #
> (01:21:30:root@binary:tracing)#
>

Did you apply the patch I added to my last email. It should have prevent
that form happening :-/

-- Steve


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/