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

[Peter Zijlstra <peterz@infradead.org>]

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.