[PATCH] powerpc: secondary CPUs signal to master before setting active and online (fixes kernel BUG at kernel/smpboot.c:134!)

[Michael Ellerman]

On Tue, 2014-12-09 at 12:54 -0800, Linus Torvalds wrote:
> On Mon, Dec 8, 2014 at 3:58 PM, Anton Blanchard <anton at samba.org> wrote:
> > Hi Ingo,
> >
> >> At that point I thought the previous task_cpu() was somewhat ingrained
> >> in the scheduler and came up with the patch. If not, we could go on a
> >> hunt to see what else needs fixing.
> >
> > I had another look. The scheduled does indeed make assumptions about the
> > previous task_cpu, but we have a hammer to fix it up called
> > select_fallback_rq.
> >
> > I annotated select_fallback_rq, and did hit a case where the CPU was
> > not active. ppc64 patch below.
> 
> Anton, I'll assume I will get this through the usual powerpc pull requests?

Yeah I'll put it in my tree unless Anton objects.

cheers