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

[Andi Kleen]

> > >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..

Yes it's in effect, and it forces the event to counter 1. 
That is correct and that restriction is still there. 
Just what is gone is the restriction to quiescence the whole PMU.

Also without that we would refuse to enable PEBS anyways
I believe.

-Andi
-- 
ak@xxxxxxxxxxxxxxx -- Speaking for myself only
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/