Re: [tip:sched/core] cpu: Remove incorrect BUG_ON

Peter Zijlstra
2010-11-23T17:15:53Z

On Tue, 2010-11-23 at 16:08 +0100, Oleg Nesterov wrote:
> > Ah,. uhm,. you mean, not do anything at all?
> >
> > Dunno, really, let me try and read the code there.
>
> Thanks. This is very minor of course, but it would be nice to
> undestand the reason. To me it looks unneeded, but I don't trust
> myself. (snippets from my previous email below).
>
>
I think because the call to __cpu_die (-> native_cpu_die) relies on the
remote cpu running the idle thread, and the CPU_DEAD notifier callback
wants to run with the guarantee the remote cpu is in fact dead as a
doornail.