[RFC] [PATCH] powerpc: Add MSR_DE to MSR_KERNEL

[Joakim Tjernlund]

Benjamin Herrenschmidt <benh at kernel.crashing.org> wrote on 2012/06/02 23:21:16:
>
> On Sat, 2012-06-02 at 20:29 +0200, Joakim Tjernlund wrote:
> >
> > hmm, where does this go w.r.t the patch? Got the feeling that the
> > best thing is to just turn MSR:DE on and be done with it?
>
> Not unconditionally, we need to have a close look, that might be ok
> specifically for BookE 32-bit, it's certainly not ok for BookE 64-bit at
> this point.
>
> For now, I'm ok with a debug CONFIG_* option.
>
> Also do we know if MSR:DE has any performance impact on any CPU ? I know
> having DACs enabled has a major impact on some for example.

I just sent a new patch, named
  [PATCH] powerpc: Add MSR_DE to MSR_KERNEL
which will only add MSR_DE for booke under CONFIG_BDI_SWITCH