Messages in this thread | | | Date | Fri, 1 Aug 2014 15:21:20 +0200 | From | Andi Kleen <> | Subject | Re: [PATCH 2/3] x86 perf: Protect LBR msrs accessing against potential #GP |
| |
> > NAK! > > > > I already said this isn't going to ever happen. > > > > Both PT and LBR are arbitrated through the kernel, therefore we can (and > > must) deny PT when there's existing LBR usage and vice versa. > > > > We will not hijack resources like this full stop end of story. > > > > Fuck hardware/BIOS, they should _NOT_ be touching this. > > > > The 3 people in the world with access to an x86 hardware debugger had > > better be competent and know WTF they're doing and the BIOS can just > > piss off right now, they should not be touching this _EVER_.
So you realize that hardware level debugging becomes impossible if everyone starts using perf?
I dont know how anyone can construct essentially sabotaging powerful debugging techniques ever as a good thing. In the end it'll just lead to more buggy software (and likely hardware) for everyone.
> > I yelled at BIOS engineers over their PMU usage and $vendor added a BIOS > knob to disable that, I'll yell at BIOS engineers again, just give me > their number. > > Really, say NO already.
Ok, so no technical reason, merely a "me vs you" power play.
Thank you for not stating that earlier and wasting everyone's time.
-Andi
-- ak@linux.intel.com -- Speaking for myself only.
| |