The Power9 host booting problem with OpenBMC kernel 5.7.x

[Artem Senichev]

On Tue, Aug 11, 2020 at 06:12:30AM +0000, Joel Stanley wrote:
> On Mon, 10 Aug 2020 at 18:48, Alexander A. Filippov
> <a.filippov at yadro.com> wrote:
> >
> > Since the kernel in OpenBMC was updated to 5.7.x we have a problem with the P9
> > hosts booting.
> > On host with one Power9 CPU the failure happens during the Petitboot is trying
> > to initialize the network and it leads to host restarts.
> > On host with two Power9 CPU the same failure happens during OS booting. It
> > increases boot time, but at the end the host OS is completely started.
> 
> Oh no. I have spent some time testing the 5.7 tree primarily on
> Tacoma, our ast2600/p9 platform. We saw some strange systemd failures,
> where services such as udevd and journald would be killed by systemd's
> watchdog functionality. I did some preliminary debugging but didn't
> find a root cause.
> 
> I'll fire up a romulus and see if it reproduces.
> 
> My guess is it's something to do with the timekeeping, irq or rcu
> code. All areas of complexity!
> 

We had similar behaviour in P8 when tried to use ColdFire FSI:
https://github.com/openbmc/openbmc/issues/3433

In this issue, htop shows 100% load of one CPU on the host and it is not an OS
task. Looks like FSI doesn't stop working and fully loads one core.

-- 
Regards,
Artem Senichev
Software Engineer, YADRO.