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

Benjamin Herrenschmidt [off-list ref] wrote on 2012/06/02 23:21:16:

On Sat, 2012-06-02 at 20:29 +0200, Joakim Tjernlund wrote:

quoted

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