Re: [PATCH 1/5] perf, x86: Don't assume the alternative cycles encoding is architectural

Peter Zijlstra
2012-06-06T14:14:36Z

On Wed, 2012-06-06 at 07:12 -0700, Andi Kleen wrote:
> On Wed, Jun 06, 2012 at 12:39:48PM +0200, Peter Zijlstra wrote:
> > On Tue, 2012-06-05 at 17:56 -0700, Andi Kleen wrote:
> > > From: Andi Kleen <ak@linux.intel.com>
> > >
> > > cycles:p uses an special cycles encoding by default. However that is not
> > > architectural, so it can only be used when the CPU is known
> > > (it already caused problems on Sandy Bridge). It may or may not work
> > > on future CPUs.
> > >
> > > So make it opt-in only. Right now I enabled it on Core2, Nehalem, Westmere
> > > and not on Sandy-Bridge or Atom.
> >
> > No.
>
> What do you mean? Are you claiming it's architectural?

I mean this patch is shite.

You don't disable it because it doesn't work some place, you fix it.

But don't bother, its already done.