Re: Re: [V2 PATCH 1/3] x86/panic: Fix re-entrance problem due to panic on NMI

Michal Hocko
2015-08-04T08:56:59Z

On Fri 31-07-15 11:23:00, 河合英宏 / KAWAI，HIDEHIRO wrote:
> > From: Michal Hocko [mailto:mhocko@kernel.org]
[...]
> > I am saying that watchdog_overflow_callback might trigger on more CPUs
> > and panic from NMI context as well. So this is not reduced to the NMI
> > button sends NMI to more CPUs.
>
> I understand. So, I have to also modify watchdog_overflow_callback
> to call nmi_panic().

yes.

[...]
> > > There is a timeout of 1000ms in nmi_shootdown_cpus(), so I don't know
> > > why CPU 130 waits so long. I'll try to consider for a while.
> >
> > Yes, I do not understand the timing here either and the fact that the
> > log is a complete mess in the important parts doesn't help a wee bit.
>
> I'm interested in where "kernel panic -not syncing: " is.
> It may give us a clue.

This one is lost in the mangled text:
[ 167.843771] U<0>[ 167.843771] hhuh. NMI received for unkn<0><0>[ 167.843765] Uh[ 16NM843774I own rea reived for unknow<0 r 16n 2d 765] Uhhuh. CPU recei11. <0known reason 7. on770] Ker<[ - not rn NMI:nic - not contt sing

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--
Michal Hocko
SUSE Labs