On Sat, 19 Mar 2016, Jiri Kosina wrote:
> > It was Jiri who made this mess by replacing WARN(), which has a very
> > distinct format, with this custom stuff.
>
> Right, this was in 55537871e ("kernel/watchdog.c: perform all-CPU
> backtrace in case of hard lockup").
>
> To be really honest, I don't really have 100% reliable explanation why I
> did it this way; I *think* it was because otherwise, in case WARN is
> preserved, we'll either
>
> - have different output format for current (warning) CPU and all the
> others (trigger_allbutself_cpu_backtrace())
>
> or
>
> - have duplicated backtrace for current CPU, one coming from WARN and one
> coming from the all-cpu backtrace
>
> > I think we should go back to the WARN() thing.
>
> I don't really have strong opinion on this, but someone should pick the
> poison from the two options above; I tried in the mentioned commit, but
> apparently not to general satisfaction :)
Hmm, or we can actually make the whole thing behave the way that was
introduced by 55537871e only in case of
sysctl_hardlockup_all_cpu_backtrace being set, and use WARN() otherwise.
I'll send out a patch for this during / after the weekend if noone else
beats me to do it.
--
Jiri Kosina
SUSE Labs
