Re: [tip:perf/core] perf/x86: Use INST_RETIRED.PREC_DIST for cycles: ppp

[Ingo Molnar <mingo@kernel.org>]

* Peter Zijlstra <peterz@infradead.org> wrote:

> On Sun, Dec 06, 2015 at 02:11:02PM +0100, Ingo Molnar wrote:
> 
> > the symptom is that latest 'perf top' and 'perf record' produces no samples.
> > 
> > So I've removed this commit and the related Skylake commit from -tip:
> > 
> >  4576ceaa56a8 perf/x86: Use INST_RETIRED.PREC_DIST for cycles:ppp
> >  ac1e1d30cf90 perf/x86: Use INST_RETIRED.TOTAL_CYCLES_PS for cycles:pp for Skylake
> > 
> > you need to do better testing next time around. Note: if you resubmit the patches, 
> > please also pick up the updates commit changelogs from the tip-bot emails, don't 
> > use your original changelogs.
> 
> OK, so I need:
> 
>  lkml.kernel.org/r/1449177740-5422-1-git-send-email-andi@firstfloor.org
>  lkml.kernel.org/r/1449177740-5422-2-git-send-email-andi@firstfloor.org
> 
> On my IVB because that keeps triggering that case with :ppp, other than
> that this seems to work fine on IVB.
> 
> I've also tried on SNB (which does not support the new :ppp thing) and
> that too works.
> 
> Sadly I do not have older hardware anymore :/ 
> 
> 
> Also, perf tools DTRT and will use :ppp by default if available.

So I checked my NHM box with your latest queue and it now works correctly. Do you 
have any idea what the difference is/was?

Thanks,

	Ingo