Re: frequent lockups in 3.18rc4

From: Thomas Gleixner
Date: Fri Nov 14 2014 - 19:36:51 EST


On Fri, 14 Nov 2014, Dave Jones wrote:

> On Fri, Nov 14, 2014 at 11:55:30PM +0100, Thomas Gleixner wrote:
>
> > So this looks more like a smp function call fuckup.
> >
> > I assume Dave is running that stuff on KVM. So it might be worth while
> > to look at the IPI magic there.
>
> no, bare metal.

Ok, but that does not change the fact that we are stuck in
smp_function_call land.

Enabling softlockup_all_cpu_backtrace will probably not help much as
we will end up waiting for csd_lock again :(

Is the machine still accesible when this happens? If yes, we might
enable a few trace points and functions and read out the trace
buffer. If not, we could just panic the machine and dump the trace
buffer over serial.

Sigh

tglx
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