Re: better oopsing when frozen

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 27 Jul 2011 00:24:11 +0200
"Rafael J. Wysocki" <rjw@sisk.pl> wrote:

> > Hi Rafael,
> > 
> > I had a problem with the kernel stopping the machine forever because I got an
> > oops while tasks were frozen. It seems to me that we should thaw when this
> > happens. How about this approach?
> 
> Well, we do something like this already for the OOM killer (see
> oom_killer_disable() and friends), so I think it would be better to
> simply extend/modify that mechanism instead of adding a new one
> doing almost exactly the same thing.
> 
> I have no complaints about adding thaw_in_oops(), though, so long as
> Andrew thinks it makes sense.

mm...  The patch as proposed is very simple, direct, explicit.  I
suspect that trying to embed this operation within some other one would
end up producing a less clear result.  Sometimes we do exceptional and
weird things, and leaving the code exceptional and weird-looking is
better than hiding it in some framework, if you follow what I mean.

It does need some code comments to explain to people what it's doing
and more importantly why it's doing it.  Also, something which doesn't
break the build when CONFIG_FREEZER=n would be nice.