Re: [PATCH 2/2] perf, x86: Enable PDIR precise instruction profiling on IvyBridge

Peter Zijlstra
2012-06-13T21:44:06Z

On Wed, 2012-06-13 at 14:36 -0700, Andi Kleen wrote:
> > This patch is just wrong on too many levels.. where do you want me to
> > start. Lets go with the restriction you mention is lifted, the SDM
> > doesn't mention this,
>
> The SDM is wrong. The restriction is Sandy Bridge only.

It would be good to mention this -- at the very least until the SDM is
revised.

> >nor does the patch actually lift it.
>
> Why not? It works for me on a Ivy Bridge.

I'm very sure you didn't test it properly then. Clearly you need a hint:

struct event_constraint intel_snb_pebs_event_constraints[] = {
INTEL_UEVENT_CONSTRAINT(0x01c0, 0x2), /* INST_RETIRED.PRECDIST */

Is still in effect, isn't it..